Assessment of the agricultural water use in Jericho governorate using sefficiency under climate change uncertainty

ii Nasser A. S. Tuqan Assessment of the Agricultural Water Use in Jericho Governorate Using Sefficiency Under Climate Change Uncertainty Doctoral Thesis Doctoral Programme in Civil Engineering Work developed under the supervision of: Professor Doutor Naim Haie November 2020 ii DECLARATION COPYRIGHTS AND TERMS OF USE BY THIRD PARTIES Third parties can use this academic work as long as the internationally accepted rules and good practices are respected in terms of copyright and the other relevant rights. The terms of use by third parties are available in the license below. If users need permission to use the content of this work under conditions that are not provided in the indicated license, they must contact the author through the RepositóriUM of Minho University. License granted to users © 2020 by the author. Submitted to the RepositóriUM of Minho University for publication under the terms and conditions of the Creative Commons Attribution (CC BY) license: http://creativecommons.org/licenses/by/4.0/ iii I dedicate this work to the memory of my late father. To my inspiring mother. To Ammar who was the first to support it. To the future of Sophia. To Lama who never gave up on me. iv ACKNOWLEDGEMENT Pursuing this journey of doctoral research work has been challenging, enriching, and life changing. I would like to acknowledge and express my great appreciation for a group of individuals and organisations who significantly contributed to the completion of this thesis. First, I would like to acknowledge and thank my supervisor, Professor Naim Haie, for his limitless support, inspiration, and guidance. He has always offered me unlimited access, unconditional support, and the optimism I needed to keep me heading forward. Without his mentorship and guidance, I would have never reached the level where I am right now. Second, I would like to acknowledge and thank my older brother, Ammar Tuqan, who personally funded the tuition fees of the first three years of my doctoral programme. Without his endless motivating support, love, and compassion, I would have never been able to join the programme in the first place. In addition, I would like to thank Ms. Givara Budeiri for establishing our connection with Eng. Mazen Ghoneim, Head of the Palestinian Water Authority (PWA). Likewise, I would like to thank Eng. Ghoneim for arranging our interview with Eng. Deeb Abdulghafour, Director-General of Water Resources Management at PWA. Besides, I would like to thank Eng. Abdulghafour for his great contribution to this work. I would also like to thank my friend, Eng. Abdul-Rahim Barqawi, who helped me to reach farmers in that region to participate in our survey. Correspondingly. I would like to dedicate a special thanks to every single farmer who took the time to participate. I am very grateful to Minho University, to the Doctoral Programme of Civil Engineering staff, especially the secretary office and the academic services, and to the Territory, Environment and Construction Centre (CTAC) for their support. I have always found myself in a very welcoming and cooperative environment while pursuing both my master and doctoral studies at UMinho. Finally, and most importantly, I would like to express my greatest gratitude to my wife, Lama Alhaddad, who has been the most influential person during my doctoral journey and my life. Lama has offered me every second she had to keep me motivated, ensuring my work-life-familystudy balance, reminding me of the big picture, and setting up my priorities in the right place. Two years ago, she gave birth to our Sophia, and ever since, she has been guiding me to become a father who can make a difference. I would have never achieved the end of this journey without having Lama next to me. v STATEMENT OF INTEGRITY I hereby declare having conducted this academic work with integrity. I confirm that I have not used plagiarism or any form of undue use of information or falsification of results along the process leading to its elaboration. I further declare that I have fully acknowledged the Code of Ethical Conduct of the University of Minho. University of Minho, November 2020. Full Name: Nasser A. S. Tuqan Signature: Nasser A. S. Tuqan Digitally signed by Nasser A. S. Tuqan Date: 2020.11.24 14:06:39 Z vi ABSTRACT Addressing water use efficiency in the Middle East is challenging due to the limited water resources availability, geopolitical complexity, climatic conditions, and a variety of managerial issues. Groundwater is the dominant water resource for Palestinians amid their inability to access other natural water resources. Jericho Governorate constitutes most of the Palestinian part of the Jordan Valley and represents a high economic significance for the nation, especially in agriculture. This made the agricultural water use in Jericho as the main user of the Eastern Aquifer Basin (EAB). The objective of this doctoral work is to assess the efficiency of the agricultural water use in Jericho, which we defined as the Water Use System (WUS), and its interaction with the main source, the Eastern Aquifer Basin (EAB), using the Sustainable Efficiency (Sefficiency) method. In addition, we aim, through developing scenarios, to understand the impacts of the uncertainty associated with climate change on our WUS’s performance and its water variables. Sefficiency is a composite multi-level efficiency indicator that is based on water balance and considers the usefulness criterion of the WUS’s variables. As Sefficiency requires, the analysis was not limited to the quantities of the different water path types within our WUS, but it also considered their quality and beneficial weights. We surveyed local farmers, interviewed a water manager, and collected an extensive dataset to achieve an understanding of the water paths dynamics and conclude our water balance schematic. Besides, we simulated six different scenarios under two representative concentration pathways (RCPs), namely RCP2.6 and RCP6.0, corresponding to the projected changes in temperature and precipitation in three intervals (years 2025, 2055, and 2090) to assess the impact of climate change on water use efficiency. The results demonstrated that: 1. Improving the quality of returns has a great positive impact. 2. Increasing water abstractions is not beneficial if it is not linked to an increase in yield production. 3. Precipitation rates can influence water use efficiency. 4. More careful treatment of the unwanted plants and a selection of high socio-economic value crops would enhance Sefficiency. Finally, the results of the developed scenarios under climate change projections indicated a minor impact on the efficiency itself, since the system is already operating under scarce water conditions; however, it showed an anticipated significant impact on the sustainability of the main source, EAB. Keywords: Eastern Aquifer Basin; irrigation management; Sefficiency; water crisis in Palestine; water use efficiency. vii RESUMO Avaliar a eficiência do uso da água no Médio Oriente constitui um desafio importante uma vez que a disponibilidade de água é muito limitada, a situação geopolítica é muito complexa, as condições climáticas são desfavoráveis e a gestão de recursos hídricos apresenta diversas fragilidades. A água subterrânea constitui o recurso hídrico dominante para os Palestinianos, não sendo possível o acesso a outras massas de água. A província de Jericó é a maior área da Palestina no vale do rio Jordão e apresenta um papel económico importante, especialmente no sector da agricultura. Assim, o uso agrícola em Jericó é responsável pelas captações mais intensas no aquífero leste ( Eastern Aquifer Basin - EAB). O objetivo deste trabalho é avaliar a eficiência do uso da água na agricultura em Jericó, sendo este o sistema selecionado para estudo ( Water Use System – WUS), assim como a sua interação com a principal fonte de água (EAB), utilizando-se o Método de Eficiência Sustentável ( Sefficiency ). Além desta avaliação, foram considerados cenários para analisar mudanças circunstanciais no sistema, tais como as mudanças climáticas, de modo a quantificar o seu impacto no desempenho do WUS. O Sefficiency é um indicador composto por vários níveis de eficiência, que é baseado no balanço hídrico e considera um critério de utilidade das variáveis do WUS. Em conformidade com os requisitos do Sefficiency , a análise considerou, além das quantidades dos diferentes tipos de fluxos de água, a sua qualidade e o seu benefício. Foram entrevistados agricultores locais e um gestor responsável pela gestão da água e foi recolhido um conjunto de dados para compreender a dinâmica dos fluxos da água no sistema selecionado, concluindo-se com a imposição de balanço hídrico nulo para o WUS. Foram simulados seis cenários de alterações climáticas correspondentes a diferentes valores de emissões combinados com distintos horizontes temporais ( representative concentration pathways - RCP) — RCP2.6 e RCP6.0 — considerando as mudanças previstas para a temperatura e a precipitação (anos 2025, 2055 e 2090). Os resultados demonstraram que: (1) melhorar a qualidade dos fluxos de retorno tem um grande impacto positivo; (2) o aumento da captação de água não é benéfico se não estiver vinculado a um aumento na produção agrícola; (3) as variações de precipitação podem influenciar a eficiência; e (4) um tratamento mais cuidadoso das espécies vegetais invasoras e uma seleção de culturas de alto valor socioeconómico aumentariam a eficiência do uso da água. Por fim, os cenários desenvolvidos para avaliação do impacto das mudanças climáticas indicaram uma menor influência nos valores da eficiência, uma vez que o sistema já está sob condições de escassez de água severas, mostrando, no entanto, um impacto significativo na sustentabilidade da principal fonte de água, a EAB. Palavras-chave: Eastern Aquifer Basin ; eficiência do uso da água; escassez da água na Palestina; gestão de irrigação; Sefficiency . xiv Figure 4.4: Water movement and resources in the study area ................................................ 69 Figure 4.5: Population of Jericho Governorate from 1997 to 2021 (Projection)....................... 70 Figure 4.6: Territorial Jurisdiction Division in Jordan Valley. ................................................... 71 Figure 4.7: Soil classification of the study area ...................................................................... 72 Figure 4.8: Geology of the study area .................................................................................... 73 Figure 4.9: Farmers' assessment of their drip irrigation systems’ quality ................................ 77 Figure 4.10: Schematic of the actual water path instances (WPIs) flowing in and out of water use system (WUS) ................................................................................................................ 79 Figure 4.11: Annual average nitrate content in selected wells in the Jordan Valley .................. 80 Figure 5.1: Sefficiency results at meso level considering farmers and managers objectives. ... 85 Figure 5.2: Sefficiency results of SC1, SC2, SC3, and SC4 .................................................... 87 Figure 6.1: Area of farmlands variation, population growth, and precipitation per season between 1993 and 2011 in Jericho governorate .................................................................... 95 Figure 6.2: Sefficiency results under RCP2.6-2025 ................................................................ 97 Figure 6.3: Sefficiency results under RCP2.6-2055 ................................................................ 99 Figure 6.4: Sefficiency results under RCP2.6-2090 .............................................................. 100 Figure 6.5: Sefficiency results under RCP6.0-2025 .............................................................. 102 Figure 6.6: Sefficiency results under RCP6.0-2055 .............................................................. 104 Figure 6.7: Sefficiency results under RCP6.0-2090 .............................................................. 105 Figure 6.8: Percentage change of PP, VA, and ET under RCP2.6 pathway scenarios ............ 107 Figure 6.9: Percentage change of PP, VA, and ET under RCP6.0 pathway scenarios ............ 108 Figure I.1: Arabic version of the survey ................................................................................ 136 Figure I.2: English version of the survey .............................................................................. 137 Figure I.3: Geographic distribution of surveyed farmers by village or city .............................. 138 Figure I.4: Number of farmers according to their answers about their farm’s area in Dunums .......................................................................................................................................... 138 Figure I.5: Number of farmers according to their answers about the quantity of water they monthly use for irrigation .................................................................................................... 139 Figure I.6: Number of farmers according to their answers about their use of artificial fertilisers and pesticides .................................................................................................................... 139 xv Figure I.7: Number of farmers according to their answers about their assessment of the weeds percentage among their crops ............................................................................................. 140 Figure I.8: Percentage of surveyed farmers based on the method of irrigation they use ........ 140 Figure I.9: Number of farmers according to their answers about their first and second sources of irrigation water ................................................................................................................ 141 Figure I.10: Percentage of surveyed farmers based on their position of reclaimed wastewater use in irrigation ................................................................................................................... 141 Figure I.11: Percentage of surveyed farmers based on the highest price they agree to pay for reclaimed wastewater ......................................................................................................... 142 Figure I.12: Farmers’ answers to the polar questions .......................................................... 143 Figure III.1: CROPWAT model using the metrological data from Jericho station .................... 151 xvi TABLE OF TABLES Table 1.1: West Bank Wadis Long-term Annual Discharge ....................................................... 8 Table 2.1: Projected water demand and deficit (assuming no increase of 2004 supplies) ....... 35 Table 4.1: Meteorological characteristics of study area extracted from Jericho weather station. ............................................................................................................................................ 65 Table 4.2: Evapotranspiration (ET) modelling results for the top 5 planted crops of each category ............................................................................................................................... 75 Table 4.3: Area under different irrigation methods (km2). ...................................................... 76 Table 4.4: Summary of the water instances quantities ........................................................... 79 Table 4.5: WUS full characteristics ........................................................................................ 83 Table 6.1: Area of farmlands, population, and precipitation per season between 1993 and 2011 in Jerich governorate ............................................................................................................ 94 Table 6.2: WUS characteristics under RCP2.6-2025 .............................................................. 96 Table 6.3: WUS characteristics under RCP2.6-2055 .............................................................. 98 Table 6.4: WUS characteristics under RCP2.6-2090 ............................................................ 100 Table 6.5: WUS characteristics under RCP6.0-2025 ............................................................ 102 Table 6.6: WUS characteristics under RCP6.0-2055 ............................................................ 103 Table 6.7: WUS characteristics under RCP6.0-2090 ............................................................ 105 Table III.1: ET details and results ........................................................................................ 153 Table III.2: ET details and results under 0.5°C increase ...................................................... 158 Table III.3: ET details and results under 1.0°C increase ...................................................... 162 Table III.4: ET details and results under 1.5°C increase ...................................................... 166 Table III.5: ET details and results under 3.0°C increase ...................................................... 170 xvii GLOSSARY OF ACRONYMS AMS American Meteorological Society AQUASTAT FAO's Global Information System on Water and Agriculture ARIJ Applied Research Institute–Jerusalem ASAE American Society of Agricultural Engineers ASCE American Society of Civil Engineers BAU Business as Usual BC Before Christ BGR German acronym of "Bundesanstalt für Geowissenschaften und Rohstoffe", meaning: German Federal Institute for Geosciences and Natural Resources CCME Canadian Council of Ministers of the Environment CE Classical Efficiency CGE Computable General Equilibrium CIA Central Intelligence Agency CIHEAM French acronym of "Centre International de Hautes Études Agronomiques Méditerranéennes", meaning: International Centre for Advanced Mediterranean Agronomic Studies CMIP5 Coupled Model Intercomparison Project - Phase 5 CROPWAT Crop water requirements calculation tool under climatic circumstances CRU CL Climatic Research Unit - Climatology CWD Crop Water Demand CWQGs Canadian Water Quality Guidelines CWQI Canadian Water Quality Index DC District of Columbia EAB Eastern Aquifer Basin EE Effective Efficiency xviii EQA Palestinian Environment Quality Authority ET EvapoTranspiration FAO Food and Agriculture Organization of the United Nations FI Farmer Irrigation GDP Gross Domestic Product GDWQI Global Drinking Water Quality Index GHG GreenHouse Gas GIS Geographic Information System GTZ German acronym of "Deutsche Gesellschaft für Technische Zusammenarbeit", meaning: German Agency for Technical Cooperation HYDE History Database of the Global Environment ICC International Criminal Court ICID International Commission on Irrigation & Drainage IHP Intergovernmental Hydrological Programme IPCC Intergovernmental Panel on Climate Change IS Irrigation Sagacity JAWRA Journal of the American Water Resources Association JWC Joint Water Committee KRB Kano River Basin MOA Palestinian Ministry of Agriculture MOPIC Palestinian Ministry of Planning and International Cooperation NAP National Adaptation Plan NEAB North-Eastern Aquifer Basin NGO Non-Governmental Organisation NIGP Portuguese acronym of "Núcleo de Investigação em Geografia e Planeamento", meaning: Research Group on Geography and Planning NIS New Israeli Shekel xix NR NonReusable OCHA United Nations Office for the Coordination of Humanitarian Affairs OLR Outgoing Longwave Radiation OS Other Sources PCBS Palestinian Central Bureau of Statistics PCM Parallel Climate Model PM Penman-Monteith PNA / PA Palestinian National Authority / Palestinian Authority PP Precipitation pp Percentage point PRECIS Providing REgional Climates for Impacts Studies PWA Palestinian Water Authority RCM Regional Climate Model RCP Representative Concentration Pathway RF Return Flow RFF Resources for the Future RP Potential Return SAM Social Accounting Matrices SDG Sustainable Development Goals SOMs Self-Organising Maps SSP Shared Socioeconomic Pathway SWR Solar Shortwave Radiation TI Tensiometer Irrigation UK United Kingdom UN United Nations UNCTAD United Nations Conference on Trade and Development xx UNEP United Nations Environmental Program UNESCO United Nations Educational, Scientific and Cultural Organization UN-ESCWA United Nations Economic and Social Commission for Western Asia UNFCCC United Nations Framework Convention on Climate Change US United States USCID United States Committee on Irrigation and Drainage USD United States Dollar VA Volume of Abstracted water VD Volume of water Upstream VU Volume of water Downstream WAB Western Aquifer Basin WAFA Arabic acronym of "ةينيطسلفلا ءابنلأا ةلاكو", meaning: Palestine News Agency WBWD West Bank Water Department WEAP Water Evaluation and Planning WHO World Health Organisation WIT Wessex Institute for Health Research & Development WPI Water Path Instances WPT Water Path Types WQI Water Quality Index WQSAM Water Quality Systems Assessment Model WUS Water Use System WWAP World Water Assessment Programme WWDR World Water Development Report WWTP WasteWater Treatment Plant 1 CHAPTER ONE. INTRODUCTION Water is a life main component that guarantees creatures’ existence, continuity, and thrive. For humankind, one of the essentials that made us who we are and let us achieve what we have accomplished is the colour of our planet, blue. Water extends beyond being the substance in which the first form of life on earth developed. It has undoubtedly become a wealth indicator, a basic element in health and hygiene, an important driver of renaissance, a war cause, and a peace guardian. Back in history, humans chose to establish their early forms of communities often in proximity to a water body. The more complex and developed human communities became over time, the greater such choice our ancestors had enhanced in planning and development. Thinking of all of the great ancient civilisations, from the Mesopotamian civilisations (including the Sumerian, Assyrian, Akkadian, and Babylonian) to the succession of the great Pharaoh monarchies, we intuitively link them to a water body. It did not take much for old cities’ founders to realise that water bodies are not only crucial to support basic life needs (drinking, irrigation, fishing, and sanitation), but their importance further extends to include other vital elements such as transportation, trade, entertainment, military purposes, and protection. Most if not all great ancient cities, which made it until today, if not flourished, have a great level of proximity to at least one water body, especially rivers. The way we previously interacted with water bodies had contributed to different perceptions about water as a resource. Nowadays, although we no longer have that much dependence when we build our new cities or grow the existing ones on the proximity to water bodies, nevertheless this is only because our understanding of water as a resource and the way we approach its management has become more advanced. Water today has a level of engagement in human activities that is unprecedented. Food, energy, manufacturing, global trade, and even modern technology are only a few examples of sectors of which their development is dependent on water. 2 1.1. Water Resources in Nature Water is continuously in motion. Scholars characterise that motion in what we know as the hydrological cycle, which is constrained by the law of conservation of mass (water balance). Such dynamics resulted to have water as a renewable source (resource). While water is preserved in quantity, however, it may very well change in location, form, quality, and thus usefulness. As we understand water resources today, we can split them into two main categories: 1. Conventional resources a. Surface water: i. Rivers ii. Lakes iii. Ice and snow b. Groundwater i. Wells ii. Springs c. Glaciers and icecaps 2. Unconventional resources a. Desalination b. Wastewater treatment and reuse c. Rainwater harvesting d. Atmospheric moisture harvesting Scholars have widely considered water as the most essential among natural resources (C. J. Vörösmarty et al., 2010) covering 70.90% of the blue planet’s surface (CIA, 2013). As illustrated in Figure 1.1, 96.5% of earth’s water is found in seas and oceans, while 1.7% in groundwater (0.77% fresh and 0.93% saline). There is 1.7% in glaciers and the ice caps of Antarctica and Greenland, and a smaller fraction in other large water bodies; 0.001% in the air as vapour, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Only 2.5% of the Earth’s water is freshwater, and 98.7% of that quantity is in ice and groundwater. Less than 0.3% of all freshwater is in rivers, lakes, and the atmosphere, and an even smaller amount of the Earth’s freshwater (0.003%) is contained within biological bodies and manufactured products (Peter H. Gleick, 1993). 3 It is important to understand that freshwater is continuously moving, flowing in rivers, evaporating and spreading as vapour, falling as rain or snow, or infiltrating slowly through soil textures as groundwater (Bidlack, Wang, & Clemens, 2004). Water evaporates annually from the oceanic surface (502,800 km3) and lands (74,200 km3). The same amount of water falls as atmospheric precipitation (458,000 km3 on oceans and 119,000 km3 on lands). The difference between precipitation and evaporation from the land surface (44,800 km3/year) represents the total runoff of the Earth’s rivers (42,700 km3/year) and direct groundwater runoff to the ocean (2,100 km3/year) (Shiklomanov, 1998). This water cycle, which is constantly controlled by the law of conservation of mass, is the principal source of freshwater to support life essentials and human activities. Figure 1.1: Distribution of Earth's water Source: (Peter H. Gleick, 1993) 1.2. Water Use Systems and Sectors Since water contributes to all human development activities, it is highly competitive among several users. Categorising water use by sectors has a considerable significance for management-related purposes. Such activity is basic for water resources’ allocation, offers a tool for better understanding of the complex water use systems, and plays a key role in shaping stakeholders’ decisions. 10 (a) The Mountain Aquifer A high-quality freshwater resource in the region (Lazarou, 2016) that has three main basins: 1. The Western Aquifer Basin (WAB) It is the largest basin among the three, where 1,767 km2 of the entire basin’s area is within the West Bank borders. Its long-term recharge ranges between 318-430 Mm3 (PWA, 2018). In 2011, Israelis withdrew 411 Mm3 from WAB, while Palestinians had 25 Mm3 (PWA, 2012). 2. The North-Eastern Aquifer Basin (NEAB) It is the smallest basin among the three, where 981 km2 of the entire basin’s area is within the West Bank. Its long-term recharge ranges between 135-187 Mm3 (PWA, 2018). In 2011, Israelis withdrew 103 Mm3 from NEAB, while Palestinians had 20 Mm3 (PWA, 2012). 3. The Eastern Aquifer Basin (EAB) It is located entirely in the West Bank and has an area of 2,767 km2. Its long-term recharge ranges between 125-197 Mm3 (PWA, 2018). The low volume of recharge is due to the climatic conditions of its location, which we will elaborate on later. In 2011, Israelis withdrew 50 Mm3 from EAB, while Palestinians had 42 Mm3. PWA claims that Israel abstracts an additional 100 Mm3 from Dead Sea springs; and restricts the Palestinians from developing any infrastructure to get additional abstractions (PWA, 2012). (b) The Coastal Aquifer The entire Gaza Strip (365 km2) lays above the coastal aquifer basin, which has a long-term recharge ranges between 55-60 Mm3. Palestinians withdraw from the coastal aquifer in staggering numbers. For example, in 2011, the total number of abstractions for both agricultural and urban uses was around 178.8 Mm3, three times the long-term average recharge. As a result, the quality of these abstractions suffers from seawater intrusion and uplift of the deep brine water level. The Palestinian Authority reported that more than 97% of the water tested samples did not meet the water quality standards of the World Health Organization (PCBS & PWA, 2019). 11 1.6. Overview of the Agricultural Water Use in Jericho Governorate and Problem Statement Description The Jordan Valley (Figure 1.4) is named after its divider the Jordan River. It extends between Nablus, Jerusalem, and Hebron Mountains chain (known in Israeli sources as Judaean and Samaria Mountains) in the west and the northwestern Jordanian highlands in the east. The Palestinian part of the valley has an estimated area of 845 km2. Administratively, two Palestinian governorates share the vast majority of the valley: the entire Jericho & Al-Aghwar Governorate (in short, Jericho) and the eastern half of Tubas and the Northern Valleys Governorate (in short, Tubas). The Valley represents a great economic value, mainly in agriculture due to its yearlong convenient climatic conditions, for both Palestinians and Israelis. Although the area under consideration falls entirely within the West Bank, it is part of a region where Israel produces 80% of its dates and 45% of its bananas (Israeli Ministry of Agriculture, 2019). As for Palestinians, the Jordan Valley contains 50% of their agricultural lands in the West Bank, producing 60% of the Palestinian’s total yield of vegetables there (WAFA, 2015). According to the latest census of the Palestinian Central Bureau of Statistics (PCBS) in 2017, the population of Jericho is 50,001, which accounts for 1.1% of Palestine’s population and makes it the least populous governorate (PCBS, 2018). The main reason behind this low population density is due to constraints that are limiting the economic development, especially in agriculture as suggested by multiple local, Israeli, and international reports (ARIJ, 2016; B’Tselem, 2013; UNCTAD, 2015). That is of no surprise considering the geopolitical complexity of this specific part of West Bank. The Oslo II Agreement in 1995 (a follow-up agreement to the Declaration of Principles known as Oslo I, which both sides signed in 1993) come in interest. The agreement designed the territorial jurisdiction dividing the West Bank into areas A, B, and C. Palestinians have control over areas A and B, but substantial restrictions in regards to land access, infrastructure and water resource development in area C (World Bank, 2009). In regards to the main water issues of concern that impact the agricultural water use sector in the Jordan Valley, it can be identified as the following: 12 Figure 1.4: Location of the Palestinian part of Jordan Valley Source: (Hamada, Vieira, & Ghodieh, 2015) 1.6.1. Limited Water Resources As mentioned earlier, Palestinians rely on groundwater for 95% of their supplies. Purchased water from Israel, treated wastewater and desalination constitute the remaining 5%. The primary purpose of the purchased water from the Israeli national water company Mekorot is for municipal uses only. In addition, the level of wastewater treatment is below the standards for direct reuse in municipal and agricultural uses. Last, the desalinated Mediterranean seawater is a source that is only available in Gaza Strip. All PWA reports suggested that Palestinians in Jericho solely 13 depended in 2011 on abstracted water from the Eastern Aquifer Basin (EAB) for their agricultural activities (PWA, 2012, 2013, 2016, 2017). 1.6.2. Arid Climatic Conditions The area is generally characterised as arid. In terms of topography, elevations vary from around 300 m above to 400 m below sea level (elevation tends to decrease heading southeastward closer to the Dead Sea) (MOPIC, 1998). Such weather conditions are suitable for growing fruits and vegetables, including dates, banana, tomato, and cucumber. Moreover, the typical Jordan Valley’s warmer winters enable farmers to have early harvest seasons, which is economically advantageous, especially for exports. Precipitation rates vary within a short distance from up to 300 mm per year in the north, down to less than 100 mm per year close to the Dead Sea (EcoPeace Middle East, 2015). The 25-yearaverage of annual precipitation recorded by the Jericho weather station is 147 mm. These precipitation rates accompanied by high evaporation records result in a greater dependence on irrigation. The PCBS reported in 2011 that 97% of the cropland areas in Jericho were irrigated (PCBS, 2012). 1.6.3. Water Management Shortcomings The Palestinians have been placing their efforts into expanding access to the available resources and exploring the potentials to develop additional resources. An extensive review of the governmental reports exposes a clear absence of strategic planning and management insights apart from the aforementioned efforts. For instance, the PWA Strategic Water Resource and Transmission Plan (PWA, 2014) and the Water Sector Reform Plan 2016–2018 (PWA, 2016) tackle filling the water gap mainly through reallocation. There is an absence of discussion about enhancing efficient use practices, facilities rehabilitation, and demand management, however, multiple scholars have suggested the latter two approaches as viable options to address water shortage in the region (Bursche, 2011; Haddad, 1998; Shevah, 2017). 14 1.6.4. Geopolitical Complexity 87% of the Palestinian part of the Jordan Valley falls within Area C (EcoPeace Middle East, 2015), making the sustainability of the Palestinian agricultural activities in that area very difficult. According to an economic monitoring report to the Ad Hoc Liaison Committee of The World Bank (World Bank, 2012), agriculture’s contribution to the Palestinian GDP dropped from 9.3% in 1999 to 4% in 2012. The report immediately links the drop to have the Jordan Valley by itself constituting 46% of total area C, denying Palestinians from a major portion of one-third of groundwater reserves and thousands of fertile hectares in the West Bank. In light of these circumstances, what Palestinians can do is to ensure making the most of every single drop of water, thus efficiency arises a key factor. 1.7. Research Framework In the following subsections, we will layout the research framework by stating the research’s motivation, clarifying its objectives, highlighting its contribution, and presenting a summary of the thesis structure. 1.7.1. Research Motivation Amidst the efforts to reach peace in the Middle East, water arises as one of the most controversial topics. One of the main discussion points on the negotiation table between the different rivals have been circling water shares’ allocation. While exploiting the different options to get access to additional water resources and to develop a solid infrastructure to enhance the adopted management approaches are all viable efforts, they become less effective as long as the water use efficiency was not made at the core of the decision-making process. In reality, the Palestinians are failing to address this matter thus far. One of the key challenges, which participates in the Palestinian failure to address water use efficiency as a decision-making indicator, is the capability to construct a comprehensive understanding of the dynamics of a water use system (WUS) and the interactions between its different variables. Moreover, the limited resources (financial, human, and technical) and 15 expertise shape a perception of urgency among the water managers to prioritise investment in expanding water quantities rather than increasing efficiency. Under informal coordination with the Palestinian Water Authority, we attempt in this work to highlight the significance to consider water use efficiency as a decision-making indicator to establish solid water policies. Furthermore, we aim to highlight the role of understanding efficiency dynamics in order to achieve a better understanding of the potential future scenarios and thus adding the comprehensiveness element into the policies. 1.7.2. Research Objectives The main objective of this research is to assess the agricultural water use efficiency in the Palestinian part of Jordan Valley during the 2010/2011 season. We selected this season in particular because it is the most recent season for which the Palestinian official sources provide a complete data set that fits the purpose of this study. Jericho governorate, which constitutes more than 70% of the Valley’s area, used more than 62% of the total Palestinian abstractions from the Eastern Aquifer Basin (EAB) (PWA, 2012) making the governorate’s agricultural sector the main user of EAB. It represents the major economic activity in the region due to the yearlong favourable climatic conditions. As mentioned earlier, the Jordan Valley contains 50% of the Palestinian agricultural lands in the West Bank, being responsible for 60% of their total vegetables’ production there (WAFA, 2015). The main research objective can be broken down into the following five sub-objectives: 1. To achieve a comprehensive understanding of the different water variables in the hydrological cycle of the water use system (WUS) under consideration, which is the agricultural water use sector in Jericho Governorate. This understanding must satisfy the law of water balance. 2. To demonstrate the relationship between the different water variables considering quantity, quality, and beneficial dimensions in terms of their impact on the WUS’s efficiency. 3. To highlight the significance of water use efficiency as a tool in the decision-making process and the water management approaches. 16 4. To demonstrate how Sefficiency can be an effective tool in highlighting the weak points and improvements opportunities within our WUS in particular, and the Palestinian agricultural sector in general. 5. To understand the impacts on our WUS’s performance and its water variables considering the uncertainty associated with climate change and future demand increases. 1.7.3. Research Contribution This research work contributes directly to the knowledge in the field of water use efficiency assessment. Its added value is represented in providing a model that can be followed in Palestine to fill the gap created by the absence of any official water use efficiency discussions. Up to the author’s knowledge at the time of writing this thesis, there are no publications that assess the performance of any water use in the study area. We could hardly find studies about assessments of water use efficiency in Palestine, apart from a few but important publications that come across efficient irrigation techniques to maximise local crop yields, e.g., Rahil and Qanadillo (2015), which are not water-centric and consider water as one of the inputs into the evaluation of other resources or outputs. For example, crop yield, as an objective, is influenced by water as well as fertilisers, seed variety, pesticides, soil types, etc. Other attempts, such as Al-Juneidi and Isaac (2000) and Alsharif, Feroz, Klemer, and Raab (2008), assessed the efficiency of local irrigation methods and the relative efficiencies of water supply systems at the municipal level as water management strategies. However, all of these assessments were based on an outdated efficiency evaluation approach, namely Classical Efficiency (CE), which is defined as the ratio of the water beneficially used to total water applied. As simple and basic as it may appear, there is a fundamental flaw behind CE, which is the absence of water balance. Many researchers highlighted the CE’s inability to address critical elements such as irrigation water recovery, water reuse, water quality, beneficial aspects of all the water flows, and to distinguish between water consumption and water use. This study will rely on one of the most novel water use efficiency assessment approaches called Sustainable Efficiency (Sefficiency), which is comprehensively water-centric and systemic. 17 1.7.4. Thesis Structure The structure of this thesis consists of seven chapters. In chapter one, we present a general overview of the field related to this research, a brief background of the water problem in Palestine, and the research framework. In the second chapter, we provide a detailed review of the available literature in this domain of research. Chapter three covers Sefficiency, which is the method that the efficiency assessment is based on, and present the methodology that our climate change scenarios’ building will follow. Then, in chapter four, we enrich the reader with an extended set of data and maps of the study area, its water resources, and general characteristics. In addition, we provide in chapter four details about the different variables needed to apply Sefficiency (water quality, quantity, and beneficence). In the fifth chapter, we present the results and their interpretation of the Sefficiency application and apply a sensitivity analysis through hypothesising four scenarios in order to understand the impacts of some potential changes or suggested improvements on the results. In chapter six, we develop different scenarios under climate change uncertainty and discuss the impacts. Finally, in chapter seven, we present the conclusion of this research work and recommendations for future potential developments. 18 CHAPTER TWO. LITERATURE REVIEW In this chapter, we will navigate through the available literature in relevance to this research. First, we will come across the emerging issue of water scarcity from a global perspective in order to provide a brief overview of the latest global position in this regard. Then, we will briefly explore the most common water resources management approaches to highlight the need for integrated efforts. In the third section, we will introduce to the reader climate change as a concept, the main drivers behind it, and a brief overview of the available literature about its impact on water resources. In section 2.4, we will briefly review some of the publications that investigated the impact of water reallocation policies. Then, section 2.5 will enrich the reader with a historical presentation of the evolution in the approaches to assess water use efficiency starting from classical efficiency, reaching the Sefficiency method. The sixth section will elaborate on the available literature that addressed the different water crisis factors in Palestine including the population growth, climate, water management, and the geopolitical complexity. Last, section 2.7 will go through the available studies and publications that investigated water use efficiency of the agricultural sector in Palestine and Jericho Governorate. 2.1. Global Water Scarcity Freshwater is an essential element for well-being and sustainable socio-economic development. According to the UN World Water Development Report (WWDR) of 2014, volume 1: Water and Energy, a range of serious global and regional issues that threaten the livelihood of a huge population, especially the three billion living on less than 2.5 USD per day, has a link to water (WWAP & UNESCO Director-General, 2014). These issues include climate, poverty, hunger, health, and finance. Demographers and archaeologists in the extensive research of Goldewijk, Beusen, Drecht, and Vos (2011) estimates the global population in 10,000 BC was 2 million. 10,000 years later, it was still under the 200 million threshold (Figure 2.1). As we already know today, the global population exceeded 7,600 million people and fast approaching 8 billion. While the human 19 population is booming, individual life expectancy has remarkably increased and our lifestyle has dramatically changed during the last 100 years. Besides, governance approaches changed significantly in the post-war era in a way that accentuated economic growth as a top priority. As a result of all of these rapid unprecedented changes, our ecosystem and natural resources suffered an extraordinary degradation. Figure 2.1: 10,000 years of global population and carbon dioxide concentration Sources: Population data from Hyde 3.1 database. CO2 concentration data from Dome C and Mauna Loa datasets. Plotted by Peter Gleick in 2019 In many regions, water shortage is considered as one of the most crucial issues. One-fourth of the world’s population is concentrated in arid or semi-arid areas, where water resources management is evolving as one of the most difficult and urgent problems (Kondili, Kaldellis, & Papapostolou, 2010). Water demand and supply substantially vary in those regions periodically, which makes the management practices, including demand management and supply chain management, very challenging. UN estimates the number of people whose right to water is not satisfied (regardless of the reason) could be as high as 3.5 billion, while 2.5 billion remain without access to improved sanitation (WWAP & UNESCO Director-General, 2014). 26 Figure 2.7: Recorded global mean temperature variance for land and water from 1850 to 2012 (a) Recorded global average for land and water surface temperature variances between 1850 and 2012 relative to the mean temperature of 1961−1990. The upper series represent the annual average values, while the lower series represent the decadal average values. (b) Map of the recorded land and water surface temperature variances between 1901 and 2012. Source: (Cubasch et al., 2013). 27 Starting with Arnell (1999), he provided a detailed assessment of the potential consequences of climate change, which will affect the global hydrological systems and water resources. Relatedly, Adams and Peck (2008) provided an informative overview of the expected physical and economic effects of climate change on water resources (focusing on water scarcities). Whereas, C. J. Vörösmarty et al. (2010) presented a comprehensive assessment of global threats to human water security, among which climate change is one of the most serious. Moreover, other authors investigated the effects of climate change on water resources in certain regions rather than the entire globe. This is useful since climate change effects are not the same everywhere. For instance, Barnett et al. (2004) described the results of an assessment of the potential effects of climate change on water resources in the western United States (the river basins of Columbia, Sacramento/San Joaquin, and Colorado). Also, Warren and Holman (2012) used baseline and future climate projections and a daily soil water balance model in order to determine the potential impacts of climate change on the Elan Valley, mid-Wales, which supplies the public water network of Birmingham city in the United Kingdom. Anyhow, when talking about the nation-scale effects of climate change on water resources, the world’s most populous country and a massive emitter of greenhouse gases, China, has to be mentioned. A comprehensive investigation about the impacts of climate change on China’s water, especially precipitation, was presented by Piao et al. (2010). They argue that, aside from the clear warming that has occurred in China in recent decades, current understanding does not allow a clear assessment resources and agriculture, and thus they recommend future work to improve regional simulations. Modelling methods of climate change impacts on water resources constitute a considerable portion of the available literature in this field. For example, the Parallel Climate Model (PCM), which is supported by the US Department of Energy, was inclusively explained and studied by Washington et al. (2000). Additionally, Guo, Wang, Xiong, Ying, and Li (2002) proposed and developed a macro-scale and semi-distributed monthly water balance model to simulate and predict the sensitivities of hydrology and water resources to global warming. Other authors contributed to this subject by making comparisons between different models, such as Slaughter, Mantel, and Hughes (2014). They compared the Water Evaluation and Planning (WEAP) model and the Water Quality Systems Assessment Model (WQSAM) regarding possible climate change effects on water quality. Their results showed that WEAP does not simulate water quality within 28 reservoirs and water quality simulation facilities within WEAP are too simple, while WQSAM demonstrated several advantages to water quality modelling. As there are many works in the literature demonstrating water resources sensitivity to climate change, upgrading water resources planning approaches, therefore, is a necessary action. In this regard, Wood, Lettenmaier, and Palmer (1997) identified major uncertainties in water resources climate change assessments as: a) climate modelling skill; b) errors in regional downscaling of climate model predictions; and c) uncertainties in future demands. They designed a simulation study to provide a better understanding of these uncertainties. Also, Charles J. Vörösmarty, Green, Salisbury, and Lammers (2000) presented numerical experiments combining climate model outputs, water budgets, and socioeconomic information in order to assess the future adequacy of freshwater resources. Moreover, Arnell and Lloyd-Hughes (2014) provided a preliminary assessment of the effects of climate change rates, its patterns, and the expected population growth on regional and global exposure to water resources stress. Relatedly, from another perspective though, Leavesley (1994) reviewed the assessment of climate change impacts using hydrologic models, which provides a framework to conceptualise and investigate the relationships between climate and water resources. 2.4. Impacts of Water Allocation Policies Decision-makers adopt water (re)allocation policies to deal with challenges, improve conditions, or mitigate severe impacts for the benefit of the users, water resources, and the surrounding environment of a WUS. Topics such as water shortage, enhancing growth and development, adapting to climate change impacts on water resources, the sustainability of the available resources and the environment, etc. have to be addressed and reflected in these policies. Many authors addressed the impacts of water (re)allocation policies on several aspects. For example, Seung, Harris, and MacDiarmid (1998) and Seung, Harris, Englin, and Netusil (2000) analysed the economic impacts of transferring surface water from irrigated agriculture to recreational use using the Computable General Equilibrium (CGE) model. Also, Fang, Roe, and Smith (2006), Juana, Strzepek, and Kirsten (2010), Qin, Su, Bressers, Jia, and Wang (2013), Qtaishat (2013), Dai, Zhang, Han, Huang, and Geng (2016), and Garrick, Chautard, and Rawlins (2019) analysed the impact of water reallocation from agriculture to other sectors (urban, 29 industrial, and others) on the economy and household income in different regions. Whereas, Rosegrant and Ringler (1999) investigated the potential impacts of water transfers from agricultural to urban and industrial areas on global food supply and demand. They found that comprehensive reforms are required to mitigate the potentially inconvenient impacts of water transfers for local communities and to sustain crop yield and output growth to meet increasing food demands at the global level. In addition, Bjornlund, Zuo, Parrack, Wheeler, and de Loë (2011) approached the same issue of irrigation water reallocation from another perspective. They investigated the public acceptance of this matter, in addition to whether such acceptance differs between urban and rural residents. They concluded that urban inhabitants are more likely to prefer government intervention while rural inhabitants are more likely to support policies that aim to protect farmers' water rights. They also found that people, both in urban and rural areas, could be categorised into three categories depending on their attitudes towards water and the environment: 1) pro-environment, 2) proeconomy, and 3) undecided. In the same context, Savenije and van der Zaag (2002) argued from a different perspective about water pricing which should primarily serve the purpose of financial sustainability through cost recovery in addition to necessarily drive adequate attention for equity considerations. On the other hand, Fielding et al. (2013) made a huge effort to promote water conservation in the field experimentally. They reported an experimental study to test the longterm impact of three different interventions on household water consumption. Also, Araral and Wang (2013) and Tortajada and Joshi (2013) focused on the important issue of public participation, where water conservation requires the engagement of the public and private sectors as well as of the society at large. Regarding the environmental impacts of water (re)allocation policies, Colby, McGinnis, and Rait (1991) argued about the continuity of water reallocation to reflect environmental benefits alongside the traditional uses of water. They presented some examples from the American recent history about changes in water allocation, forced by law, to mitigate hazards threatening the nature. Also, Howe, Schurmeier, and Shaw Jr (1986) discussed the shortcomings of water users, especially related to quantity and quality return flow effects, confirming that they can be minimised through changes in the administrative framework of the water rights system. They proved that an efficient water allocation system must integrate quantity and quality management. Furthermore, Weber (2001) modelled a suggested optimal allocation of surface water and pollution rights in a river system with water quality constraints in order to answer the question of 30 whether it is possible to maintain water quality under a certain alternative mechanism for allocating surface water and pollution rights. 2.5. Evolution of Water Use Efficiency From Classical Efficiency to Sefficiency The approaches and methodologies to assess water use efficiency vary because reaching a comprehensive approach that represents and evaluates the dynamics and performance of a certain water use system (WUS) is a complex matter. The better we understand the complexity of the great number of variables influencing water use systems, the more critical scholars have been toward the classical definition of efficiency – Classical Efficiency (CE): the ratio of the water beneficially used to total delivered. CE was adopted by Orson Winso Israelsen (1932) and O. W. Israelsen (1950), which are pioneered publications in irrigation. Later, further studies went more in-depth about CE in irrigation such as Feddes, Kowalik, and Zaradny (1978) in their book about the theory of field water use and crop production, and French and Schultz (1984) who investigated the relations between the crop of wheat yield and water use from a technical standpoint. Following the same path, Burt et al. (1997) presented a detailed definition and framework of CE in irrigation during their presentation and evaluation of irrigation performance indicators. The technical engineering element in enhancing water use efficiency in irrigation gained attention among several authors. For instance, Onta, Loof, and Banskota (1995) developed and applied an optimisation model for an irrigation system for land and water allocation during the dry season in order to obtain optimum cropping patterns for different management strategies. Similarly, Small and Rimal (1996) evaluated under varying degrees of water shortage, using a simulation model, the irrigation performance implications of alternative water distribution rules for a dry season. Within this context, Howell (2001) discussed the concept of enhanced CE in irrigation and its impacts on water conservation from different viewpoints. In order to approach enhanced water efficient use in irrigation, he recommended increasing the output per unit of water and reducing water losses to unusable sinks (engineering aspects), reducing water degradation (environmental aspects), and reallocate water to higher priority uses (societal aspects). One last example, Gohar and Ward (2011) evaluated the potential economic benefits that can be 31 supported by Egypt's irrigation water use through developing an integrated catchment scale framework. CE’s use as an efficiency assessment method in irrigation is common worldwide up to date (AlJuneidi & Isaac, 2000; Çakir, Kanburoglu-Çebi, Altintas, & Ozdemir, 2017; Ibragimov et al., 2007; Liu et al., 2017). However, many researchers highlighted the CE’s inability to address critical elements such as irrigation water recovery, water reuse, water quality and to distinguish between water consumption and water use (Haie & Keller, 2014; M. E. Jensen, Harrison, Korven, & Robinson, 1980; Marvin E. Jensen, 2007; Pereira, Cordery, & Iacovides, 2012; Willardson, Allen, & Frederiksen, 1994). They emphasized the necessity of improving the definition of water use efficiency using a more comprehensive approach. Furthermore, Willardson et al. (1994) and Allen, Clemmens, and Willardson (2005) discussed terms such as evaporated, reusable, nonreusable, and consumed fractions. Hence, important contributions aiming toward a more comprehensive and complete understanding of water use efficiency and water system performance evaluation started taking place in the last couple of decades. An explicit example of this transition is Irrigation Sagacity (IS), which is defined as the ratio of irrigation water beneficially and reasonably used to the total irrigation water applied. This new efficiency term (IS) was first presented by Kruse (1978) and later improved by Solomon and Burt (1999). Nevertheless, Keller and Keller (1995) introduced a more comprehensive concept into the knowledge and understanding of water use efficiency to overcome the limitations of CE, which is Effective Efficiency (EE). They defined EE as the irrigation water consumed (evaporated) by crops divided by the effective use of water (the effective inflow minus the effective outflow). The major step forward in the definition and approach of Keller and Keller (1995) is the ability of its application on other uses of water and other measures of change in water quality or value, in other words, the inclusion of water quality dimension. This important addition, which came after solely quantitative approaches of water use efficiency, paved the road toward other significant contributions in this regard. Later, Haie and Keller (2008) developed EE models based on water quantity and quality, with the possibility of considering water reuse (recycling), for two scales (the first is called Project EE and the second is called Basin EE). They compared then between CE and EE results and found that CE values were less than EE due to water reuse absence in calculations. Thus, the real importance of their work comes from their defence favouring EE over 32 CE, especially after the increased voices among researchers advocating the use of different concepts instead of efficiency concepts. Finally, Haie and Keller (2012) made another major step forward by incorporating a third dimension to the definition of water use efficiency, which is the beneficence of water use. They employed the concept of water balance, based on conservation of mass, to develop three levels of composite efficiency indicators (macro, meso, and micro levels) called Sustainable Efficiency, or Sefficiency. They achieved that through the definition of Usefulness Criterion, which is defined as the product of quality and beneficial weights assigned to the quality and the beneficial attributes of water use. The authors continued their efforts with other informative publications (Haie, 2016; Haie & Keller, 2014) to better describe and, at the same time, examine the terminology associated with water use efficiency. Also, they proposed integrated terminologies, starting from flow-path types in water balance and expanded into the three-level efficiencies formulation. Lately, Professor Naim Haie has gathered the available knowledge about Sefficiency in his book “Transparent Water Management Theory” (Haie, 2020). Sefficiency application to evaluate the performance of the water use system started to emerge recently. Apart from the publication produced out of this work (Tuqan, Haie, & Ahmad, 2020), two studies by M.T. Ahmad and Haie (2018) and Muhammad Tajuri Ahmad, Haie, Yen, and Tuqan (2018) used Sefficiency to evaluate the efficiency and water allocation of the Kano River Basin (KRB) project in Nigeria. In addition, they assessed the impacts of population growth and climate change on the system’s performance. Another example is a study by Kazem Attar, Noory, Ebrahimian, and Liaghat (2020), who used Sefficiency to investigate the quality of return flows and to examine its impact on the assessment of efficiency in irrigation. 2.6. Water Crisis in Palestine Water resources management in the Middle East is challenging due to the variety of complex issues that threatens water sustainability in that region. Palestine is no exception. Scholars have addressed the different elements in Palestine that construct a crisis level of water resources’ availability, accessibility, quality, and efficiency. These elements include, but are not limited to: 1. Increased demand due to the high population growth rates. 2. The impact of a changing climate in a semi-arid to arid region. 3. Absence of the strategic dimension within the national- 33 level of water resources management and planning. 4. The geopolitical complexity caused by sharing the transboundary freshwater resources between hostile neighbours. 2.6.1. Increased Demand Due to Population Growth The Palestinian Water Authority (PWA) estimates the projected demands for all sectors according to the population. As in the Water Status Report of 2011 (PWA, 2012), they estimated the demand of each governorate on the basis of 150 litres per capita per day (l/c/d). They do not provide a clear justification for the adoption of this criterion other than the referral to the World Health Organisation (WHO) standards. However, the purpose of the WHO’s recommendations of minimum water requirement for water service level is to promote health. Moreover, in their Domestic Water Quantity, Service, Level and Health 2003 guidelines, the WHO estimated that 100 l/c/d is sufficient to ensure meeting all hygiene and basic domestic needs (Howard et al., 2003). While the WHO estimation mainly refers to domestic use, the PWA however, refers to the total demand of all use sectors. Whether the 150 l/c/d criterion is well developed and justified or not, the bottom line is that the PWA estimates the Palestinian demand based on population, which is, in fairness, not unique by all means. According to the latest estimates of the Palestinian Central Bureau of Statistics (PCBS, 2020) in Figure 2.8, the average population growth rate in Palestine is around 2.66%, which led to an increase in population from 2.78 million in 1997 to 4.73 million in 2017 (the year in which PCBS conducted the most recent census). The projections for the four years that follow the last census (from 2018 until 2021) show a continuation of the same trend, where the population is expected to reach 5.23 million in 2021. Since PWA estimates water demand based on population, such an increasing trend consequently means a continuous increase in demand. Among the few authors who addressed this issue and its impact on the future scenarios of the region were Jayyousi, Jarrar, McKee, and Kaluarachchi (2004). They presented a short but focused estimation of the supply-demand gap due to the population growth reaching the year 2020 according to the Palestinian national targets at the time of publishing their work. As shown in table 2.1, they concluded that the deficit in 2004 was around 177 Mm3/year and quickly increasing to reach a supply-demand gap of 513 Mm3/year in 16 years if the existing supplies at that time are not expanded. 34 Figure 2.8: Population of Palestine from 1997 to 2021 (Projection) Where r: the population growth rate. Source: (PCBS, 2020) It is worth mentioning that Jayyousi et al. (2004) differentiated between the urban and domestic demands and the agricultural demand. They followed the national targets that were based on the WHO guidelines of 150 l/c/d in the urban areas and 100 l/c/d in the rural areas. As for agriculture, they adopted a local study conducted at An-Najah National University and sponsored by the Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) in 1996. It estimated the average annual consumption of irrigated crops around 272 kg per capita; broken down into 179 kg vegetables, 40 kg melons, and 53 kg oranges and bananas. Such a distinction is absent in the national water strategic development reports and literature. Others, such as J. L. Chenoweth and Wehrmeyer (2006) and J. Chenoweth (2011), analysed the impact of population increase among the three neighbouring countries, Jordan, Isreal, and Palestine, which share the transboundary surface and groundwater resources. They used the population growth projections for the year 2050 based on the United Nations Population Division estimates. In regards to Palestine, their analysis concluded that a stable political environment is 2,783,084 2,871,568 2,962,226 3,053,335 3,138,471 3,225,214 3,314,509 3,407,417 3,508,126 3,611,998 3,719,189 3,820,801 3,922,130 4,023,462 4,124,795 4,226,410 4,327,751 4,429,084 4,530,416 4,632,025 4,733,357 4,854,013 4,976,684 5,101,152 5,227,193 r = 2.66% 0 1,000,000 2,000,000 3,000,000 4,000,000 5,000,000 6,000,000 POPULATION YEAR 35 necessary and predicted that the West Bank will be able to cover the increased demand only through gaining a larger share of the available resource. Nevertheless, the Gaza Strip will need desalination, water imports, or a combination of both to bridge the gap. Table 2.1: Projected water demand and deficit (assuming no increase of 2004 supplies) Presented by (Jayyousi et al., 2004) Year 2000 2005 2010 2020 Sector Demand Deficit Demand Deficit Demand Deficit Demand Deficit Domestic 226 125 288 187 332 231 432 331 Agriculture 224 52 266 94 299 127 353 182 Total 450 177 554 281 631 358 785 531 Similarly, J. Lautze and Kirshen (2009) and Jonathan Lautze, Reeves, Vega, and Kirshen (2005) have simulated eight different scenarios to project the conditions in the years 2020 and 2025. The scenarios varied between Business as Usual (BAU) to the official Palestinian desired and claimed position under population growth and climate change uncertainties in both years. The results showed, on the one hand, that these uncertainties would create an allocation’s disproportion and environmental vulnerabilities within the BAU scenarios. On the other hand, under the Palestinian desired position, conditions are more equitable, but associated with critical ecological consequences, especially when considering climate change impacts. 2.6.2. Vulnerability to the Climatic Conditions Palestine has a total area of 6,020 km2 (United Nations Statistics Division, 2012). Despite the small number, the variation in climatic zones is considerable due to the variation in topography. Within tens of kilometres, the elevation could drop from more than 800 m above mean sea level at some points in the central part of West Bank down to less than 400 m below mean sea level next to the Dead Sea. A considerable number of authors addressed the great vulnerability to a change in the climatic conditions in Palestine and its impact on the availability and distribution of the water resources, especially amidst the other complications. For example, as mentioned earlier in their discussions about the population growth issue J. L. Chenoweth and Wehrmeyer (2006), J. Lautze and Kirshen (2009), and J. Chenoweth (2011) could not but to include the climate changes potential impacts 42 design for the city of Tubas as a study area and a brief plan for a sustainable implementation of such a project. Although they did not assess efficiency, but their article is useful in promoting a sustainable practice that would enhance the efficiency of agricultural water use systems. A similar attempt on a small scale in Jenin city as a study area can be found in the publication of Z. A. Mimi, Ziara, and Nigim (2003). 2.7.2. Water Use Efficiency in Jericho When it comes to the Jordan Valley area and the city of Jericho, the studies become scarcer. One of the few local attempts was Barghouthi (2009), who addressed the water use efficiency, especially in irrigation, through investigating the water use variables of a local important spring called Ein Sultan. Although the study is not very well structured and has some flaws from a technical perspective, it is unique in introducing terms such as micro and meso levels of efficient allocation of irrigation water. The author concluded that there are water use inefficiencies in the utilisation of the spring, and the potential cause behind these efficiencies is mainly having a supply-driven rather than demand-based management approach. While the argued cause makes sense considering the managerial challenges in the region, however, the author’s conclusions are not strongly supported by the article’s methodology and results. Nonetheless, although Ziad A. Mimi and Abu Jamous (2010) approached water use efficiency in a primitive way, they importantly attempted to assess the impact of climate change on the total crop water demand in Jericho. They followed standard models to estimate evapotranspiration, effective precipitation, and leaching requirements. Their results showed that a 3°C increase in temperature combined with a 20% decrease in precipitation would require a 2.9 Mm3 increase in water supplies in order to compensate for the increased crop water demands. Besides, Al-Khatib, Shoqeir, Özerol, and Majaj (2017) addressed the reuse of treated wastewater in irrigation in Jericho city area as a case study. They focused their analysis on the understudied governance element. Their study managed to identify governance-related concerns, including the weak coordination between the different governance stakeholders. This gab is obvious in the overlapping responsibilities. Other concerns they identified included the absence of a robust legislative system and a set of laws to govern the overall processes, in addition to the absence of infrastructure development. 43 Apart from wastewater reuse, Al-Jayyousi (1999) suggested to enhance irrigation efficiency in Jericho through rehabilitation of the existing irrigation distribution network. The author proposed a design that is based on transforming the existing irrigation open channel system to a distribution network of pressurised pipes. Finally, and after careful consideration of the available literature up until the time of writing this thesis, we can confidently state that the topic of water use efficiency of the agricultural sector in Palestine, especially under climate change impacts, is understudied. This is more evident when it comes to the area of Jericho city and Eastern Aquifer Basin. Furthermore, among the tens of articles we reviewed, we could find no publication that addressed any of those topics in Palestine using an efficiency evaluation approach other than classical efficiency. 44 CHAPTER THREE. METHODOLOGY In this chapter, we will clarify the methodology of which this research work is based on. First, we will provide a brief description of Sefficiency, which is the adopted method for the water use efficiency assessment that is carried out in this research. Then, in the following three sections (3.2 to 3.4), we will explain the definitions and estimation methods of the different variables required to apply Sefficiency in regards to their quantity (section 3.2), quality weight (section 3.3), and beneficial weight (section 3.4). Finally, section 3.5 will come across the approach to construct the different climate change scenarios. 3.1. Sefficiency Sefficiency was first introduced by Haie and Keller (2012) in their extensive publication: “Macro, Meso, and Micro-Efficiencies in Water Resources Management: A New Framework Using Water Balance” . It is a composite indicator to estimate efficiency using the law of mass conservation (water balance), considering two types of total flows: total inflow and total consumption. The preliminary steps are to characterise a water use system (WUS), whether that system was a farm, basin, region, city, or something else. WUS characterisation in Sefficiency is to locate WUS boundaries; to distinguish between the different inflow and outflow water path types (WPTs) (Figure 3.1); and to define the associated attributes, namely quality and benefits — the useful dimension. 3.1.1. Water Path Types Water path types (WPTs) are the nine different possible flow types in any given WUS. Any WPT can potentially consist of zero, one, or more water path instances (WPIs), which are the real water instances flowing in or out of the WUS. As shown in Figure 3.1, there are two categories of WPTs based on the flow direction, namely, inflow and outflow pathways. Inflow paths can be of three sources:  VA: Volume of abstracted water from the main source or alternatively VU; the level of the aquifer at the beginning of the period 45  PP: Precipitation  OS: Volume of water from other sources (e.g., purchased water) Figure 3.1: Generic water use system (WUS) schematic including all water path types. Outflow paths can be of four types:  RF: Return flow to the main source or alternatively VD; the level of the aquifer at the end of the period  ET: Evapotranspiration  RP: Potential return (the water returned to the environment, but not the main source)  NR: Nonreusable, non-ET water consumption (e.g., evaporation resulting from nonagricultural activities) Useful remarks about the distinction between the different WPTs are available in (Haie & Keller, 2014). 3.1.2. Water Balance The change in storage over the analysis period (for example annually) should sum to zero, thus: total inflow = total outflow. Translating water balance: (VA + OS + PP) – (ET + RP + RF + NR) = 0 (3.1) It is important to bear in mind the consistency of flow units, e.g., Mm3. The (VA + OS + PP) part of the equation is the total inflow, which will be denoted by index 𝑖 (inflow models), and subtracting ET and NR from the total inflow (VA + OS + PP – RF – RP) represents the WUS effective consumption, which will be denoted by index 𝑐 (consumption models). 𝑖 and 46 𝑐 are binary indices with values 0 or 1, where 𝑖+𝑐=1, in order to differentiate between the two models. To clarify, Equation (3.1) can be rewritten to include these two types of totals: [(VA + OS + PP) – c(RF + RP)] – [(ET + NR) + i(RF + RP)] = 0 (3.2) For example, giving the values 𝑖=1 and 𝑐=0 in Equation (3.2) will result in Equation (3.1). The significance of considering these two totals is a result of their association with real-water saving mechanisms, whether it was consumptive or abstraction savings. Further details about the link between the two totals and the saving mechanisms can be found in the method’s development publication (Haie & Keller, 2012). 3.1.3. Usefulness Criterion Sefficiency considers two dimensions for making a variable useful: beneficial dimension, b, and quality dimension, q. Having both dimensions defined, then, the useful dimension of a WPI = X is Xs: Xq=WqX×X Xb=WbX×X WsX =WbX ×WqX Xs=WsX×X (3.3) Where: Xq: the quality dimension of X. Xb: the beneficial dimension of X. WqX: the quality weight of X. WbX: the beneficial weight of X. WsX: the usefulness weight of X. Weights are between zero and one with zero being the poorest. The quality weight of a water instance can be quantified based on its physical, chemical, and biological characteristics. While its beneficial weight, however, can be quantified according to tangible and intangible values of water and in accordance with stakeholder participation processes. 47 3.1.4. Levels of Water Management Sefficiency assesses the WUS’s performance at three different levels: macro-, meso-, and microEfficiencies (3ME). Macro-Sefficiency (𝑀𝑎𝑐𝑟𝑜𝑆𝐸) assesses the impact of a WUS on the main source. Meso-Sefficiency (𝑀𝑒𝑠𝑜𝑆𝐸) relates to a situation between micro and macro levels indicating, for example, the impact of return flows generated by a WUS. Micro-Sefficiency (𝑀𝑖𝑐𝑟𝑜𝑆𝐸) is about the internal efficiency of a WUS, i.e., no consideration of its returns nor impact on the main source (Haie, 2016; Haie & Keller, 2012, 2014). 𝑀𝑎𝑐𝑟𝑜𝑆𝐸 is more suitable for a larger (transboundary) scale assessment that is centred on the aquifer. It would require measures of water table level at the beginning and end of the analysis period to replace VA and RF with VU and VD, respectively. 𝑀𝑖𝑐𝑟𝑜𝑆𝐸, on the other hand, ignores the impact of the return flow on the main source, which is an important objective for this work. Therefore, the assessment in this study will focus on Sefficiency at meso level in order to reflect on the interaction between the useful outflow and total flow. A proper application would be the impact of return instances the system generates. Such an application examines, among different aspects, the impact of the WUS on the downstream users, including the ecosystem. To calculate the Sefficiency of a WUS at the meso level, we use the following equation – for its proof see (Haie & Keller, 2012) or (Haie, 2020): MesoSE= [ ET+ NR + 𝑖(RF+ RP) VA+ OS + PP − 𝑐(RF + RP)]s (3.4) The presence of 𝑖 or 𝑐 indicates the I/O models, i.e., 𝑖𝑀𝑒𝑠𝑜𝑆𝐸 means 𝑀𝑒𝑠𝑜𝑆𝐸 calculated as in full inflow model, while 𝑐𝑀𝑒𝑠𝑜𝑆𝐸 means meso-Sefficiency calculated as in consumption model. Full inflow 𝑀𝑒𝑠𝑜𝑆𝐸 gives the percentage of total useful inflow that is useful outflow, whereas consumptive 𝑀𝑒𝑠𝑜𝑆𝐸 provides the percentage of effective consumption that is useful consumption. 3.2. Water Instances Quantities As mentioned earlier, water instances are categorised based on their paths into three inflow paths types and four outflow paths types. Based on a robust analysis and understanding of the variables 48 of the water use system (WUS), we can determine how many instances each path type consists of, if any. The first step into characterising the WUS is to estimate the volumes of each of the instances that constitute the different WPTs in that WUS. 3.2.1. Precipitation (PP) Precipitation (PP) is the amount, usually expressed in millimeters or inches of liquid water depth, of the water substance that has fallen at a given point over a specified period of time (AMS, 2019). Typically, meteorological agencies and specialists frequently report precipitation rates for a given area using their field measurements from one or more meteorological stations in that area. In lack of field measurements, PP amounts can be estimated using techniques such as the isohyetal maps of the area under consideration, which are maps constructed of lines that connect points of equal long-term averages of precipitation depth. As we are looking for a volume of water rather than depth, and to keep consistency in units, average PP depth is multiplied by the area under consideration to estimate the volume of precipitation in a volumetric unit such as Mm3. 3.2.2. Abstraction From the Main Source (VA) The amount of water abstracted from the single main water source of the WUS, which could be a river, a basin, or any other source that is central to the stakeholders and users in the WUS. At a national level, official water authorities and agencies measure and control such amounts. Alternately, the volume of water upstream or water table before abstraction (VU) can replace VA value if the assessment considers the macro-level Sefficiency. For this study, the main source is an aquifer basin. Thus, we will depend on the water authority official reports of withdrawals. Such reports commonly include details about the distributions of withdrawals among the different sectors of water use. 3.2.3. Other Sources (OS) It is not rare for a large size WUS to have additional sources besides the precipitation and main source’s abstractions. For instance, abstractions from secondary sources, purchased water, and reclaimed water reuse can be forms of other sources. 49 3.2.4. Evapotranspiration (ET) Evapotranspiration is the combined processes through which water is transferred to the atmosphere from open water and ice surfaces, bare soil, and vegetation that make up the earth's surface (AMS, 2019). ET estimation, alternatively, the total crop water demand (CWD), is of high complexity due to the variety of the included variables. We will use the CROPWAT model (Smith, 1992), which is based on the Penman-Monteith method, illustrated in FAO Irrigation and Drainage Paper 56 by Allen, Pereira, Raes, and Smith (1998). To estimate the reference ET (ETo), which is the evapotranspiration rate of a referenced crop (usually alfalfa) at standard meteorological conditions, the PM equation is: 𝐸𝑇𝑜=0.408∆(𝑅𝑛−𝐺)+ 𝛾 900 𝑇+273𝑢2(𝑒𝑠−𝑒𝑎) ∆+𝛾(1+0.34𝑢2) (3.5) Where 𝐸𝑇𝑜: Referenced evapotranspiration in 𝑚𝑚.𝑑𝑎𝑦−1 𝑅𝑛: Net radiation at the crop surface in 𝑀𝐽.𝑚−2.𝑑𝑎𝑦−1 𝐺: Soil heat flux density in 𝑀𝐽.𝑚−2.𝑑𝑎𝑦−1 𝑇: Mean daily air temperature at 2 𝑚 height in ℃ 𝑢2: Wind speed at 2 𝑚 height in 𝑚.𝑠−1 𝑒𝑠: Saturation vapor pressure in 𝑘𝑃𝑎 𝑒𝑎: Actual vapor pressure in 𝑘𝑃𝑎 𝑒𝑠−𝑒𝑎: Saturation vapor pressure deficit in 𝑘𝑃𝑎 ∆: Slope vapor pressure curve in 𝑘𝑃𝑎.℃−1 𝛾: Psychrometric constant in 𝑘𝑃𝑎.℃−1 Then, to convert ETo to actual crop ET (ETc), the crop coefficient approach shall be used: 𝐸𝑇𝑐=𝐾𝑐×𝐸𝑇𝑜 (3.6) Where: ETc: crop evapotranspiration in mm.day-1 Kc: crop coefficient (dimensionless) 50 The crop coefficient, Kc, is the ratio of the crop ETc to the reference ETo, and it represents an integration of the effects of primary characteristics that distinguish the crop under consideration from a reference crop. The crop coefficient integrates the effect of characteristics that distinguish a typical field crop from a reference grass, which has a constant appearance and a complete ground cover. Consequently, different crops will have different Kc coefficients. The changing characteristics of the crop over the growing season also affect the Kc coefficient. Finally, as evaporation is an integrated part of crop evapotranspiration, conditions affecting soil evaporation will also affect Kc. We will use the metrological data from the Jericho station to estimate the reference crop evapotranspiration (ETo) per each growing period. The growing period and the crop coefficient (Kc) for each of the different crop types were estimated based on the extensive local research work in this field conducted by the Applied Research Institute—Jerusalem (ARIJ) in 1998 (J. Isaac & Sabbah, 1998). Then, we utilised Kc to estimate the actual crop evapotranspiration (ETc) per the growing period of each crop. The areas of irrigated farmland in the governorate for each crop were acquired from the 2010 agricultural census (PCBS, 2012). Furthermore, we verified the growing periods in ARIJ’s book for each crop by comparing them with the growing periods of several crops listed by the surveyed farmers in one of the questions in the survey, and with the opinion of local agricultural engineers. 3.2.5. Return Flow (RF) Return flow is the volume of water that returns to the main source. Such volume can be one or more of different forms including runoff outflowing to a stream, infiltration within an aquifer basin, discharge of urban wastewater networks (as long as its destination is the main source), etc. The quality of the returned flow is not considered here. Alternately, in case of using VU as a type of inflow when the assessment considers the macro-level Sefficiency, the volume of water downstream after the occurrence of the return flow (VD) can replace RF, regardless of the water source type. Estimation of RF depends on the form of it, which by itself varies from a WUS to another. In this study, as the main source in question is an aquifer basin, we will analyse the spatial characteristics, the used irrigation methods, and the soil classification of the area under consideration. In addition, we will include questions to the local farmers in the survey that will 51 help us to draw a better understanding of the study area, including the irrigation patterns, methods, and the irrigation equipment’s conditions and quality. 3.2.6. Potential Return (RP) The definition of potential returns is very comparable to RF, but differs in terms of the outflow destination downstream. Hence, it is the volume of water that returns to a different downstream destination other than the main source. The estimation of RP is also similar to RF while bearing in mind the downstream direction. 3.2.7. Nonreusable (NR) The nonreusable is the consumed volume of water, apart from ET, that does not return to the main source nor can be reused in any form within the defined WUS. Similar to the other variables, the identification, and thus the estimation, of the nonreusable volumes differ between the different types of water use systems. For agricultural systems, the evaporation that is not accounted for in ET is an example of NR. NR can be estimated either through analysis or by using it the slack variable to achieve water balance. In this study, we will use the same approach to estimate NR and RP to account for NR as well. The next chapter includes details about the applied approach to estimate RF, RP, and NR. 3.3. Quality Weights Water quality variables are of high complexity due to the variety of conditions and characteristics under consideration from physical to chemical and biological conditions. Moreover, the quality dimension is not only about the quality of water and the system that water flows through, but also the level of toleration for a design quality, which is a management decision (Haie & Keller, 2012). Water quality is a qualitative characteristic that is usually indicated by a lot of field or lab tests and measurements. There are several quantification approaches to quantify water quality. For example, the water quality index (WQI) (Lumb, Sharma, & Bibeault, 2011) is a single number that expresses water quality by aggregating the measurements of water quality parameters (such 58 Figure 3.4: SOMs analysis of average temperature and precipitation changes in Palestine under RCP6.0 using CMIP5. Source: (Smithers et al., 2016) 59 Figure 3.5: Projected changes in temperature in Palestine under RCP2.6 and RCP6.0 for the years 2025, 2055, and 2090. Source: (Smithers et al., 2016) 60 Figure 3.6: Projected changes in precipitation in Palestine under RCP2.6 and RCP6.0 for the years 2025, 2055, and 2090. Source: (Smithers et al., 2016) 61 CHAPTER FOUR. CHARACTERISING THE WATER USE SYSTEM In this chapter, we will enrich the reader with an extended set of data and maps of the study area, its water resources, and general characteristics. Then, we will provide details about the characterisation approaches to achieve a representative understanding and estimation of the different variables needed to apply Sefficiency (water quantity, quality, and beneficence). The maps included in this chapter, where there is no reference indicated below the map, are a result of the author’s ArcMap GIS work based on the shapfiles provided from the Palestinian Ministry of Planning and International Cooperation (MOPIC, 1998). This ministry was later renamed as the Ministry of Planning. 4.1. Study Area This study will use Sefficiency as an approach to assess the agricultural water use efficiency in the Palestinian part of Jordan Valley during the 2010/2011 season. We selected this season in particular because it is the most recent season for which the Palestinian official sources provide a complete data set that fits the purpose of this study. The Jordan Valley is one of the most significant areas in Palestine for several reasons. It represents a great economic value and sustainable development potentials for the Palestinians. The main water source in the Palestinian part of the Jordan Valley is the Eastern Aquifer Basin (EAB). Jericho governorate, home of Jericho city, which some scholars including Kenyon (1954) claimed to be the oldest town in the world, is selected as the study area. The main reasons for selecting Jericho as a study area are: 1. During the season under consideration, Jericho used more than 62% (26.0 Mm3) of the total Palestinian abstractions (41.7 Mm3) from EAB (PWA, 2012). The governorate’s agricultural sector used 24.2 of the 26.0 Mm3, making it, by far, the main user of EAB in Palestine. 2. It constitutes more than 70% (592.9 km2) of the total area of the Jordan Valley. 62 3. Jericho has a vital position within the Palestinian national economy. It is a governorate with a substantial volume of agricultural activities in addition to its being an attractive destination for religious, archaeological, and medical tourism. 4. It has a weather station providing metrological data for the governorate. 4.1.1. Location The Jordan Valley extends between the Nablus, Jerusalem, and Hebron Mountains chain (known in Israeli sources as Judaean and Samaria Mountains) in the west and the northwestern Jordanian highlands in the east. The Palestinian part of the valley has an estimated area of 845 km2 (MOPIC, 1998). Administratively, two governorates share the vast majority of the valley: the entire Jericho and Al-Aghwar Governorate (in short, Jericho) with an area of 592.9 km2 and the eastern half of Tubas and the Northern Valleys Governorate (in short, Tubas) with an area of 252.1 km2. As in Figure 4.1, Jericho is located in the central-eastern part of the West Bank. It shares boundaries with the Hashemite Kingdom of Jordan to the east, Nablus, Ramallah & Al-Bireh, and Jerusalem governorates to the west, Tubas governorate to the north, and Jerusalem governorate and the Dead Sea to the south. 4.1.2. Topography As shown in Figure 4.2, the elevations in Jericho Governorate vary from around 300 m above to 400 m below sea level. The elevation tends to decrease heading southeastward closer to the Dead Sea. 4.1.3. Climate and Precipitation The area under consideration is arid. Jericho enjoys relatively warm winters compared to the rest of the Palestinian governorates, hence it became a destination for winter housing. Summers are considerably hot with temperatures that exceed 40°C in a typical summery day there. Meteorological characteristics of Jericho are summarised in Table 4.1. 63 Figure 4.1: Location and land use of the study area 64 Figure 4.2: Topography of the study area 65 Precipitation rates (Figures 4.3) vary within a short distance from up to 300 mm per year in the north, down to less than 100 mm per year close to the Dead Sea (EcoPeace Middle East, 2015). The 25-year-average of annual precipitation recorded by the Jericho weather station is 147 mm. These precipitation rates accompanied by high evaporation records result in a greater dependence on irrigation. The Palestinian Central Bureau of Statistics (PCBS) reported in 2011 that 97% of the cropland areas there were irrigated (PCBS, 2012). Table 4.1: Meteorological characteristics of study area extracted from Jericho weather station. Weather conditions data cover years 1972–1997. Evaporation and precipitation data cover years 1988–2012. Source: Palestinian Meteorological Department—Ministry of Transport. Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Avg. high Temp. (°C) 19.1 20.9 24.3 29.3 33.7 36.7 37.8 37.6 36.1 32.3 26.4 20.5 Avg. low Temp. (°C) 7.4 8.3 10.5 14.2 17.6 20.4 22.1 22.4 21.2 17.9 12.9 9 Mean Temp. (°C) 13.2 14.6 17.4 21.7 25.6 28.5 29.9 30 28.6 25.1 19.6 14.7 Avg. relative humidity (%) 70 65 57 45 38 38 40 44 47 51 60 70 Avg. daily sun (h) 5.5 5.9 7.7 9.3 9.4 11.8 11.7 11.6 10.5 8.7 6.5 5.6 Avg. atm pressure (mbar) 1048 1046 1044 1041 1040 1037 1034 1035 1039 1042 1046 1048 Avg. wind speed (km/h) 4.5 5.2 6.5 8.1 7.9 7.7 8 7.4 6.3 4.7 4 3.8 Avg. evaporation (mm) 71 74 128 182 259 288 294 274 225 148 96 62 Avg. precipitation (mm) 36 29 20 9 1 1 0 0 0 6 17 28 66 Figure 4.3: Long-term average annual precipitation of the study area 67 4.1.4. Water Resources On the topic of water supplies, as mentioned earlier, Palestinians rely on groundwater for 95% of their supplies. Purchased water from Israel, treated wastewater and desalination constitute the remaining 5%. The primary purpose of the purchased water from the Israeli national water company Mekorot is for municipal uses only. In addition, the level of wastewater treatment is below the standards for direct reuse in municipal and agricultural uses. Last, the desalinated Mediterranean seawater is a source that is only available in Gaza Strip. In 2011, all PWA reports suggested that Palestinians in Jericho solely depended on abstracted water from the Eastern Aquifer Basin (EAB) for their agricultural activities (PWA, 2012, 2013, 2016, 2017). EAB has a total area of 2,767 km2 (PWA, 2018), which is around half of the total area of the West Bank, and a long-term average recharge of 125–197 Mm3 (PWA, 2013). The annual yield abstracted from EAB by Palestinians tends to increase: 23 Mm3 in 2003 (J. Lautze & Kirshen, 2009), 42 Mm3 in 2011 (PWA, 2012), 53 Mm3 in 2012 (PWA, 2013), up to 64.8 Mm3 in 2015 (latest published PWA update) (PWA, 2017). Israelis also abstract from EAB their allocation (40 Mm3) according to the Oslo II Agreement in 1995 (a follow-up agreement to the Declaration of Principles known as Oslo I, which both sides signed in 1993). The Palestinian’s share in the agreement is set to be 54 Mm3 per year, while “an additional 78 Mm3 are to be developed” (Shamir, 1998) – presumably by both sides. PWA claims that the Israeli side abstracts from EAB an estimated additional 100 Mm3 (PWA, 2012), exceeding the agreed 78 Mm3 while preventing Palestinians from developing any further abstractions there. On the other hand, the Israeli Water Authority reports Palestinian undesirable practices, including the drilling of 300 unauthorised wells until 2011, the disposal of untreated wastewater, and the dereliction of developing unconventional sources (Israel Water Authority, 2012; Tal-Spiro, 2011). Out of the 42 Mm3 that the Palestinian abstracted from EAB in 2011, Jericho got 26 Mm3 (62%). Jericho’s share in that year was broken down into 24.19 Mm3 for the agricultural sector and 1.81 Mm3 for the domestic use. This is a clear indicator of the volume of the agricultural activities in the governorate. Figure 4.4 provides an overview of the water resources movement in the region. It shows the main catchments around Jericho and the wadies that runoff as a result. As mentioned earlier in 74 In addition, in order to acquire the stakeholder and public participation data, we interviewed the Director-General of Water Resources Management at PWA, Eng. Deeb Abdulghafour, and surveyed a random sample of 40 local farmers. The selection of farmers considered both population density and geographic distribution across the study area. For instance, 30% of the sample were farmers from Jericho city, which is the area of highest density, another 30% from the northern villages (green areas in the north of Jericho in Figure 4.1) and the remaining 40% were from the remaining villages across the governorate. 4.2. WPIs Quantities Estimation Considering the generic schematic in Figure 3.1, the three main inflow path types are water abstractions from EAB (VA), precipitation (PP), and other sources (OS). In the opposite direction, the four main outflow path types are evapotranspiration (ET), aquifer basin recharge (RF), other return types replenishing any source other than the aquifer (RP), and what flows out without replenishment potentials within the system itself nor its neighbour(s) (NR). 4.2.1. Inflow WPIs The total abstracted water from the Eastern Aquifer Basin as reported from the Palestinian Water Authority (PWA) for agricultural use during the 2010/2011 season, abbreviated here as VAPWA, was 24.19 Mm3 (PWA, 2012). Precipitation inflow during the same season was noticeably low, with a total of 99 mm, which is 48 mm below the 25-year-average. In fact, multiple Palestinian sources refer to 2010/2011 as a drought season. The Palestinian Central Bureau of Statistics (PCBS) surveyed 36.28 km2 of irrigated farmland in the area (PCBS, 2012), hence, the 99 mm precipitation produced 3.59 Mm3 (PP). Finally, as there was no water supplied from other sources than EAB, the water path type of other sources (OS) is assumed to be negligible. The outflow variables, estimated in the next subsection, will suggest that there must be additional inflows to satisfy the law of water balance. Due to the absence of any further data in regards to water supplies, we will need to consider an inflow slack variable for water balance. 75 4.2.2. Outflow WPIs To estimate ET, alternatively, the total crop water demand (CWD), as explained in subsection 3.2.4, we used the CROPWAT modelling tool. Metrological data from the Jericho station (Table 4.1) were used to estimate the reference crop evapotranspiration (ETo) per each growing period. The growing period and the crop coefficient (Kc) for each of the different crop types were estimated based on J. Isaac and Sabbah (1998). Then, we utilised Kc in order to estimate the actual crop evapotranspiration (ETc) per the growing period of each crop. Irrigated areas for each crop were acquired from the 2010 agricultural census (PCBS, 2012). Table 4.2 shows CWD modelling results for the top five planted crops of each category (categorised into trees, vegetables, and field crops following the baseline of PCBS). The final estimated value of the total crop water demand was 33.09 Mm3 for the season under consideration (2010/2011). Full details about ET data are available in Appendix III. Table 4.2: Evapotranspiration (ET) modelling results for the top 5 planted crops of each category Crop Area (km2) ETo (mm/period) Kc ETc (mm/period) CWD (Mm3/year) Trees Date 4.79 1668 0.935 1559 7.47 Banana 1.11 1330 0.872 1160 1.29 Lemon 0.25 1668 0.796 1327 0.33 Grape 0.25 1668 0.509 850 0.22 Valencia Orange 0.14 1668 0.678 1132 0.16 Vegetables Squash 7.60 983 0.904 888 6.75 Eggplant 3.88 1504 0.751 1130 4.38 Maize 3.83 806 0.720 580 2.22 Tomato 2.38 806 0.832 670 1.59 Jew's Mallow 0.71 1668 0.832 1388 0.98 Field Crops Wheat 0.66 925 0.840 777 0.51 Sorghum 1.18 257 0.720 185 0.22 Dry Onion 0.10 1145 0.916 1049 0.10 Mint 0.04 1668 0.832 1388 0.05 Barley 0.29 240 0.715 171 0.05 76 In order to estimate RF, RP, and NR, we analysed the spatial characteristics and the used irrigation methods in the region. The soil classification of the area under consideration ranges from clay loam to sandy loam. In addition, the entire sample of farmers who participated in our survey mentioned that they use drip irrigation as their only irrigation technique, which confirms the PCBS and Ministry of Agriculture 2010 agricultural census results as shown in Table 4.3. Table 4.3: Area under different irrigation methods (km2). Source: (PCBS, 2012) Crop Type Surface Irrigation Drip Irrigation Sprinklers Irrigation Field Crops 0.17 1.91 0.07 Vegetables 1.28 24.65 0.37 Trees 0.43 5.46 0.06 Total (%) 1.88 (5.5%) 32.01 (93.0%) 0.51 (1.5%) Despite the common perception among farmers that drip irrigation’s non-beneficial water consumption is nearly negligible, scholars have been less keen on this idea. A number of studies such as Burt, Mutziger, Allen, and Howell (2005) demonstrated that classic (surface) drip irrigation could produce non-beneficial consumption in evaporation. Moreover, one of the main issues of drip irrigation is the high potential of excess deep percolation (J. Schwankl & R. Hanson, 2007), which can occur as a result of applying the total crop water demand to a relatively small soil surface area. We have asked the farmers to assess the drip irrigation systems they use in terms of technical quality. Survey results in Figure 4.9 indicate 42% of farmers use the best available drip irrigation options in the market, while 45% and 13% use systems that need improvements or require replacement, respectively. Although drip irrigation systems’ design imperfections and technical malfunctions are beyond the scope of this work, we understand that such issues lead to a higher percentage of water consumed in non-beneficial forms for the farmers. On a different note, we asked the local experts about the time interval in which farmers typically irrigate, which helps in understanding the direction of these non-beneficially consumed quantities. Irrigation application during warm times of the day could lead to higher evaporation, while application during the cold times of the day potentially generates higher infiltration rates. Every expert confirmed that farmers irrigate during the cold periods, in either mornings, evenings, or a combination of both. 77 Figure 4.9: Farmers' assessment of their drip irrigation systems’ quality To summarise, we are assessing the agricultural water use of an area that has precipitation in low intensity and frequency, high permeable soil types, semi-arid to arid weather conditions allyear-long, and a dominance of irrigated farmlands via drip irrigation. Based on the available data and survey results, it was estimated that 15% of the applied irrigation from abstractions were flowing into directions other than satisfying CWD, which agrees with previous studies such as Martínez and Reca (2014). Thus: RFEq +NREq =0.15×VA (4.1) Where: RFEq: Infiltration back to EAB due to irrigation equipment shortcomings. NREq: Evaporation caused by irrigation equipment shortcomings. Similarly, we cannot anticipate that the crop will benefit from the entire rainfall quantity to achieve its water demand under the aforementioned circumstances. Following the FAO guidelines about effective rainfall (Brouwer & Heibloem, 1986; Smith, 1992), if the monthly precipitation rate is lower than 17 mm, the effective rainfall is negligible, meaning that the crop will get none of this rain to meet its water demand. In only 3 months (January, February, and December), the precipitation rate exceeded the 17 mm/month threshold by a small margin, which indicates that only 8 mm of effective precipitation out of the 99 mm total precipitation was available over the entire growing season. 42% 45% 13% Best in the market Needs improvement Needs replacement 78 The remaining 91 mm, therefore, flows into other directions. Due to soil type, low intensity, and quantity of rain events and weather conditions, it was assumed that the surface runoff was negligible. Thus, RP = zero, and: RFPP+NRPP =91 mm×Area (4.2) Where: RFPP: Infiltration back to EAB after rainfall events. NRPP: Evaporation after rainfall events. 4.2.3. Water Balance Application Applying water balance (Equation (3.1)) of the quantities calculated thus far indicates an excess of water flowing out of the system compared to inflows from groundwater withdrawal and precipitation. According to the PWA official reports and local agricultural experts, there are no other water resources available, hence, the difference is compensated through unreported abstractions from local wells or springs. This instance will be abbreviated as VAUnr. Engineer Deeb Abdulghafour confirmed this conclusion during our interview. He also explained that a substantial number of unreported wells and springs are old and family inherited properties, which farmers do not report in fear of closure. Therefore, and in order to reflect the actual flows in and out of the WUS, Equation (3.1) was adapted to: VAPWA +VAUnr +PP=ET+RFEq +NREq +RFPP +NRPP (4.3) As a result, the generic schematic in Figure 3.1 can be transformed to represent the actual water flow instances depicted in Figure 4.10. Applying Equations (4.1), (4.2), and (4.3) resulted in the values of RFEq, NREq, RFPP, NRPP, and VAUnr, taking into consideration that VAUnr is the slack variable in order to maintain water balance as explained. 79 Figure 4.10: Schematic of the actual water path instances (WPIs) flowing in and out of water use system (WUS) Table 4.4 summarises the final estimation results of the quantities of the different water instances in our water use system. Table 4.4: Summary of the water instances quantities Variable PP VAPWA VAUnr ET RFEq NREq RFPP NRPP 𝑿 (Mm3) 3.59 24.19 14.40 33.09 3.47 2.32 1.98 1.32 4.3. Quality Weights Assessment Water quality variables are of a high complexity due to the variety of conditions and characteristics under consideration. Moreover, the quality dimension is not only about the quality of water and the system that water flows through, but also about the level of toleration for a design quality. For instance, PWA reported around 45% of EAB wells’ abstraction in 2011 from shallow layers of poor water quality (i.e. brackish). This becomes more noticeable among the springs’ abstraction, especially the closer we move towards the Dead Sea area. Therefore, we would anticipate the quality weight to reflect that by being less than 1. Yet, if farmers used such water for planting high tolerance crops, such as dates, that should mitigate the impact of salinity on the quality weight. 80 As farmers adapt their practices to the available level of water quality, it was assumed that the quality of the water abstracted would be as high as 0.9. Note that, as Eng. Abdulghafour confirmed, the PWA applies some basic level of treatment on the abstracted quantities, hence, we could not set this value to be as high as 1. In regard to the precipitation, evapotranspiration, and the nonreuseables, since they are WPTs of pure water forms, their quality values were assumed to be 1 for each. The nitrate concentration results of the PWA-tested samples of randomly selected wells in the region between 2005 and 2009 (Figure 4.11) indicate a trend of increase. Figure 4.11: Annual average nitrate content in selected wells in the Jordan Valley It is important to note here that: 1. FAO’s guidelines for interpretations of water quality for irrigation suggest a slight to moderate degree of restrictions on use at 5–30 mg/l nitrate concentration range (Ayers; 5 8 4 10 5 2 57 45 37 42 48 30 29 31 35 42 44 51 93 0 10 20 30 40 50 60 70 80 90 100 2005 2006 2007 2009 Nitrate Concentration (mg/l) Year 19-14/003 19-14/062 19-14/067 19-14/073 20-17/018 81 & Westcot, 1985), which includes 3 of the 5 tested wells and provides a sense of controllability. 2. Nitrate is not the only parameter that defines water quality. Despite these two facts, the aim here is not to assess the water quality itself but to estimate the impact weight of the WUS’s return flow on the main source. Although this trend is more apparent in certain wells than others, it indicates a considerable intensity of agricultural activities, especially between 2007 and 2009. Consequently, the quality weight of the return flow would be significantly low. We assumed this weight to be 0.2, and then made part of the scenario analysis later. 4.4. Beneficial Weights Assessment Sefficiency reflects on the system’s objectives of each of the stakeholders via quantifying the benefit of a water use accordingly. Typically, the different interests of stakeholders vary from being economic, social, environmental and even political. The key here is to realise the differences in objectives and in water management and efficiency perceptions between the local farmers and the local managers in the Palestinian Water Authority (PWA). From the survey conducted, farmers clearly expressed their main objective from using the abstracted water is to maximise their yield. While 4 out 10 farmers expressed difficulty in getting access to the water they need, around 58% mentioned they will expand their agricultural activity if they get access to more water. From the managers’ perspective, the Director General of Water Resources Management at PWA, Eng. Deeb Abdulghafour, mentioned that their main objective is, on the one hand, to keep a balance between satisfying the high demand, which is vital for the economy and, on the other hand, to preserve the aquifer from its steady-state of deterioration. He added that the PWA plans to do that through getting access to other resources, mainly unconventional resources such as wastewater treatment, in order to mitigate the pressure on the EAB system. In fact, 70% of the surveyed farmers indicated they were willing to use treated wastewater in irrigation. When it comes to the beneficial weight for all forms of inflow, both sides agree to set the beneficial weights for these instances at relatively high values. Although this is true for the abstracted water instances (VAPWA and VAUnr), our analysis of the effectiveness of rainfall events for crop demand 82 suggests that the beneficial weight of PP cannot be as high. Based on that analysis, we estimated the beneficial weight of PP for both managers and farmers as equal to 0.6. For the outflow instances, however, managers consider preserving the long-term level of the basin, while farmers do not share such concerns. Thus, the beneficial value for RF is quite different between the two parties. Engineer Abdulghafour confirmed that all returned quantities to the aquifer are essential, hence we set the beneficial values of RF instances to be as high as 1 for managers. On the other hand, only 2 out of every 10 farmers expressed interest or showed awareness about the significance of these quantities, thus we set the WbRF value for farmers to be 0.2. Note that the aforementioned 70% of farmers, who are willing to use treated wastewater, were referring to the planned PWA projects of municipal wastewater treatment plants. The NR instances are non-useful by definition. Neither the interviewed manager nor the surveyed farmers expressed an interest in it. Therefore, we assumed the beneficial weight values of NR instances to be as low as 0.1 for both stakeholders. We could have assumed this weight to be 0 as well, nevertheless, the influence of such difference (0 or 0.1) on the final results is rather negligible. In regard to ET’s beneficial value, which represents the yield, although the entire WUS is designed to maximise it, in reality, it cannot be set to the highest possible value. This is because of the unwanted plants (weed) issue. In the survey, 47.5% of farmers claimed they treat these plants proactively using pesticides and do not suffer this issue. The remaining 52.5% of farmers estimate the size of these plants as a percentage of their total farmlands: two-third estimated 15%, while the other third estimated 10%. Based on these estimates, the beneficial weight value of ET was set to 0.92. Finally, Table 4.5 summarises the full characteristics of our water use system, including the WPIs’ quantities, quality, and beneficial weights. 83 Table 4.5: WUS full characteristics Variable 𝑿 (Mm3) 𝑾𝒒𝑿 𝑾𝒃𝑿 Farmers 𝑾𝒃𝑿 Managers 𝑿𝒔 (Mm3) Farmers 𝑿𝒔 (Mm3) Managers PP 3.59 1 0.6 0.6 2.15 2.15 VAPWA 24.19 0.9 1 1 21.77 21.77 VAUnr 14.40 0.9 1 1 12.96 12.96 ET 33.09 1 0.92 0.92 30.44 30.44 RFEq 3.47 0.2 0.2 1 0.14 0.69 NREq 2.32 1 0.1 0.1 0.23 0.23 RFPP 1.98 0.2 0.2 1 0.08 0.40 NRPP 1.32 1 0.1 0.1 0.13 0.13 90 advantageous. Likewise, managers could also contribute through establishing policies and programmes that enhance the selection of high socio-economic value crops. Since yield production is the centre of this WUS, the results of this scenario show a significant increase in the system performance with such a change. The performance of both farmers’ and managers’ objectives increased significantly in both models by more than 6 pp. 91 CHAPTER SIX. IMPACTS OF CLIMATE CHANGE ON SEFFICIENCY In this chapter, we will examine the climate change impacts on the different water path instances and Sefficiency results. In order to do that, we will construct in section 6.1 different scenarios that include potential changes in temperature and precipitation under the climate change projections presented in the Palestinian National Adaptation Plan (NAP) to Climate Change. In addition, we will evaluate the validity of including the population growth in these scenarios. In sections 6.2 and 6.3, we will present and discuss the changes in the water use system’s variables under the constructed scenarios, and the impact of these changes on the Sefficiency results. 6.1. Scenarios Building No one can predict future events; instead, scientists attempt to simulate the potential impacts of likely changes following a scientific methodological approach within a margin of uncertainty. Most of the common approaches to simulate changes are based on analysing historical trends and existing conditions to project future behaviours. Climate change is a clear example of where such approaches are used. 6.1.1. Climate Change Considerations In this study, we are assessing the efficiency of agricultural water use in a defined WUS in which farmers mainly depend on irrigated farming. Among the most critical factors that influence irrigated farming are the climatic conditions. Such influence is most evident in precipitation and evapotranspiration. In the upcoming sections and subsections, we will focus our analysis on temperature and precipitation variations due to their significance. On the other hand, we will neglect the variations in sunshine hours, relative humidity, and wind speed despite their influence in ET. This is because, according to Forster et al. (2007), the projected changes in these variables are insignificant and widely uncertain. 92 As explained in section 3.5, we will rely in this domain on the simulation results of the Palestinian National Adaptation Plan (NAP) to Climate Change report (Smithers et al., 2016). Consequently, we will adopt their time intervals for scenarios’ building, RCPs’ selections, and results of the temperature and precipitation projections. These projections are outcomes of a simulation on an annual basis and we assumed them to be uniform over the 12 months. We understand that such an assumption does not represent reality, however, the objective here is to assess a range of impacts, and thus we claim that the effect of the monthly variations of these changes is minor to our objective. Under two representative concentration pathways (RCPs), namely RCP2.6 and RCP6.0, we will hypothesise six different scenarios corresponding to the projected changes in three years. These scenarios will be identified as the following: - RCP2.6-2025 - RCP2.6-2055 - RCP2.6-2090 - RCP6.0-2025 - RCP6.0-2055 - RCP6.0-2090 To clarify, for instance, RCP2.6-2055 corresponds to the projected temperature and precipitation changes under RCP2.6 in the year 2055. RCP2.6 is the pathway considering a change in climate resulting from a target change in energy flux equals 2.6 W/m2 by the year 2100. 6.1.2. What About Population Growth? Undoubtedly, the Middle East is one of the regions where the population is growing. Palestine and Jericho are not an exception with positive population growth rates of 2.66% and 2.27%, respectively. If this study had been about domestic water use, population growth would have been a key. Nonetheless, since the WUS under consideration for this study is the agricultural water use, the argument may differ. Despite Jericho’s size that represents around 9% of the total area of Palestine, it is home for around 50% of West Bank’s agricultural lands, where 60% of the total vegetable production in that region takes place (WAFA 2015). Hence, the impact of any growth in the overall Palestinian 93 population, not only in Jericho Governorate, on the agricultural sector has to be carefully examined. From a broad perspective, population growth as an indicator of the agricultural activities’ expansion in a given region is a robust approach. As discussed in subsection 2.6.1, Jayyousi et al. (2004) adopted a local study to estimate the average annual consumption of irrigated crops, which was around 272 kg per capita; broken down into 179 kg vegetables, 40 kg melons, and 53 kg oranges and bananas. An analysis could follow a similar approach to estimate the increased demand, and thus the projected increase in the agricultural activities according to the population growth. However, by following that, such an analysis would be falling under the assumption that the potential to develop additional farmlands exists. On the contrary, taking a closer look at the agricultural development in Jericho over the past 25 years, we cannot see a trend of expansion. Although 2010/2011 was the only season in which the Palestinian Central Bureau of Statistics conducted a comprehensive agricultural census, we could gather from scattered reports PCBS previously published rough estimates of the total number of farmland dunums. The data we found covers most of the seasons in the period between 1993 and 2011. For the seasons with no data, we assumed their inputs based on interpolation for simplicity since we are looking for a trend rather than accurate estimates. Table 6.1 and Figure 6.1 summarise these data against the population growth during these years to compare. Besides, we thought it would be useful to include in this analysis the annual precipitation rates in each of those years to reflect if there was any correlation between the volume of agricultural activities and the precipitation rate in a given season. According to the outcomes of Figure 6.1, we can observe no correlation between the precipitation rates and the agricultural activities in a given season. This is quite expected in an arid region that heavily depends on irrigated farming. More importantly, over the 18-year-period shown in the graph, there is an apparent irregularity in the number of farmland dunums from one year to another. Nonetheless, several indicators lead us to believe farmlands are not expanding (if not shrinking). First, the season that has the most farmlands dunums is the oldest among those analysed (1993/1994). In addition, the most recent season shown in the graph has the third least number of farmland dunums. Finally, as we have discussed earlier, agriculture’s 94 contribution to the Palestinian GDP dropped from 9.3% in 1999 to 4% in 2012 (World Bank, 2012). Table 6.1: Area of farmlands, population, and precipitation per season between 1993 and 2011 in Jerich governorate Source: A collection of reports that can be found in (PCBS, 2016) Season Area of Farmlands (Dunums) Population Precipitation (mm) 1993/1994 57,467 28,116** 147.0*** 1994/1995 46,276 29,106** 147.0*** 1995/1996 39,547 30,098** 147.0*** 1996/1997 36,037 31,089 224.6 1997/1998 36,749 32,105 90.1 1998/1999 34,179 33,145 48.7 1999/2000 41,159 34,188 152.8 2000/2001 37,524 35,162 148.4 2001/2002 39,399* 36,154 147.0*** 2002/2003 41,274 37,173 194.0 2003/2004 50,089 38,232 128.5 2004/2005 44,752 39,378 117.0 2005/2006 45,194 40,559 147.0*** 2006/2007 45,607 41,776 115.2 2007/2008 52,150 42,587 118.8 2008/2009 46,859* 43,389 115.7 2009/2010 41,569* 44,184 124.2 2010/2011 36,278 44,973 99.0 * Area was estimated via interpolation due to lack of official data ** Population was estimated according to the growth rate due to lack of official data *** Due to lack of official records, the number presented is the long-term annual average As a result, we can conclude that the assumption of a potential expansion in the agricultural activities in the region is not an accurate representation of reality. Therefore, we assumed that the population growth will not have a significant impact on the size of the agricultural activities, and henceforth excluded from our scenario analysis. 95 Figure 6.1: Area of farmlands variation, population growth, and precipitation per season between 1993 and 2011 in Jericho governorate 6.2. Sefficiency Under RCP2.6 Pathway RCP2.6 pathway represents the UNFCCC’s target for the maximum increase in global mean temperature of 2.0°C. According to the Palestinian NAP, the most likely changes under RCP2.6 pathway in Palestine are a temperature increase of 0.5°C in 2025, 1.0°C in 2055, and 1.5°C in 2090. For precipitation, there is a projected slight decrease of 2% in 2025, 5% in 2055, and goes up to 10% in 2090. In the following subsections, we will present for each year’s scenario a table that summarises the new quantities of the water paths instances and the changes in Sefficiency at meso level (𝑀𝑒𝑠𝑜𝑆𝐸𝑠) comparing to the values in the 2010/2011 season. 0 50 100 150 200 250 0 10,000 20,000 30,000 40,000 50,000 60,000 70,000 mm Dunum | Capita Season Dunums of Farmlands Population Precipitation 96 6.2.1. RCP2.6-2025 Scenario Under this scenario, the temperature will increase by 0.5°C and the precipitation will decrease by 2%. Table 6.2 presents the new values of each variable in our WUS considering these temperature and precipitation changes. The full details about the changes in ET values for each crop under this scenario and the following remaining scenarios are available in Appendix III. As shown in the table, along with the anticipated decrease in precipitation that leads to a 1% decrease in both RFPP and NRPP, there is a relatively significant 4% increase in ET. These increases have necessarily to be compensated by additional abstractions to maintain water balance. The WUS will need as much as an 11% increase in abstractions considering the aforementioned changes under RCP2.6-2025 to maintain the same yield production, which will result in a 4% increase in both RFEq and NREq. Under this scenario and the following remaining scenarios, we assumed the additional abstractions to be unreported abstractions rather than VAPWA, but in either way, each would have the same influence on Sefficiency results. Besides, we analysed the impact of these changes on the values of the quality and beneficial weights of each variable and found that there would be no tangible change. Table 6.2: WUS characteristics under RCP2.6-2025 Variable 𝑿 (Mm3) % of Change 𝑿𝒔 (Mm3) Farmers 𝑿𝒔 (Mm3) Managers PP 3.52 -2 2.11 2.11 VAPWA 24.19 0 21.77 21.77 VAUnr 15.94 11 14.35 14.35 ET 34.37 4 31.62 31.62 RFEq 3.61 4 0.14 0.72 NREq 2.41 4 0.24 0.24 RFPP 1.96 -1 0.08 0.39 NRPP 1.31 -1 0.13 0.13 Figure 6.2 illustrates the changes in Sefficiency results under RCP2.6-2025 scenario from both managers’ and farmers’ perspectives. As shown in the figure, from the managers’ perspective, each of 𝑐𝑀𝑒𝑠𝑜𝑆𝐸𝑠 and 𝑖𝑀𝑒𝑠𝑜𝑆𝐸𝑠 has insignificantly increased by 0.1 percentage points (pp). 97 Similarly, from the farmers’ perspective, 𝑐𝑀𝑒𝑠𝑜𝑆𝐸𝑠 and 𝑖𝑀𝑒𝑠𝑜𝑆𝐸𝑠 has both slightly improved by 0.2 pp. The absence of a significant change (neither positive nor negative) clearly shows that the increase in ET value under such a change in climatic conditions would not impact the WUS’s performance if it was accompanied by a proportionate increase in groundwater withdrawals. This is expected in a region under water shortage, where higher quantities of withdrawals above the demand are not expected. Figure 6.2: Sefficiency results under RCP2.6-2025 6.2.2. RCP2.6-2055 Scenario Under this scenario, the temperature will increase by 1.0°C and the precipitation will decrease by 5%. Table 6.3 provides the new values of each variable in our WUS considering these temperature and precipitation changes. As shown in the table, along with the anticipated 5% decrease in precipitation that leads to a 3% decrease in both RFPP and NRPP, there is a 5% increase in ET. These changes have inevitably to be compensated by more groundwater withdrawals to maintain water balance. The WUS will need up to a 15% increase in abstractions considering the 84.1% 84.0% 84.3% 84.2% 86.5% 86.1% 86.6% 86.2% 82.5% 83.0% 83.5% 84.0% 84.5% 85.0% 85.5% 86.0% 86.5% 87.0% iMesoSEs cMesoSEs RCP2.6-2025 Managers 2010/2011 Managers RCP2.6-2025 Farmers 2010/2011 Farmers 98 changes under RCP2.6-2055 to maintain the same level of agricultural activities, which will lead to a 5% increase in each of RFEq and NREq. We analysed the impact of these changes on the values of the quality and beneficial weights of each variable and found that there would be no tangible change. Table 6.3: WUS characteristics under RCP2.6-2055 Variable 𝑿 (Mm3) % of Change 𝑿𝒔 (Mm3) Farmers 𝑿𝒔 (Mm3) Managers PP 3.41 -5 2.05 2.05 VAPWA 24.19 0 21.77 21.77 VAUnr 16.52 15 14.87 14.87 ET 34.82 5 32.03 32.03 RFEq 3.66 5 0.15 0.73 NREq 2.44 5 0.24 0.24 RFPP 1.92 -3 0.08 0.38 NRPP 1.28 -3 0.13 0.13 Figure 6.3 shows the changes in Sefficiency results under RCP2.6-2055 scenario from both managers’ and farmers’ perspectives. Similar to the results under RCP2.6-2025, for each of 𝑐𝑀𝑒𝑠𝑜𝑆𝐸𝑠 and 𝑖𝑀𝑒𝑠𝑜𝑆𝐸𝑠 considering both perspectives, there is no significant change in Sefficiency results due to the allocation of enough abstractions to address the aforementioned increases in ET, RFEq, and NREq. 6.2.3. RCP2.6-2090 Scenario Under this scenario, the temperature will increase by 1.5°C and the precipitation will decrease by 10%. Table 6.4 presents the new values of each variable in our WUS considering these temperature and precipitation changes. As shown in the table, along with the anticipated considerable decrease in precipitation that leads to a 7% decrease in both RFPP and NRPP, there is a relatively weighty 7% increase in ET. These increases shall be compensated by additional abstractions (a significant 19% increase in VAUnr) to maintain water balance and the same rate of yield of production, which will result in a 7% increase in both RFEq and NREq. 99 The impacts of these changes on the values of the quality and beneficial weights of each variable are negligible. Figure 6.3: Sefficiency results under RCP2.6-2055 Figure 6.4 illustrates the changes in Sefficiency results under RCP2.6-2090 scenario from both managers’ and farmers’ perspectives. As shown in the figure, from the managers’ perspective, each of 𝑐𝑀𝑒𝑠𝑜𝑆𝐸𝑠 and 𝑖𝑀𝑒𝑠𝑜𝑆𝐸𝑠 has insignificantly increased by 0.2 percentage points (pp). Similarly, from the farmers’ perspective, 𝑐𝑀𝑒𝑠𝑜𝑆𝐸𝑠 and 𝑖𝑀𝑒𝑠𝑜𝑆𝐸𝑠 has both slightly improved by 0.4 pp. The overall results of the three intervals’ scenarios under RCP2.6 pathway indicate a minor impact on the Sefficiency results, meaning that the WUS will maintain a similar performance at the meso level considering the projected climatic changes under this pathway. However, the more the temperature increases and precipitation decreases, the further abstractions that the system will need to maintain the same level of agricultural activities, which represents a substantial concern on the aquifer’s sustainability. 84.1% 84.0% 84.3% 84.3% 86.5% 86.1% 86.7% 86.3% 82.5% 83.0% 83.5% 84.0% 84.5% 85.0% 85.5% 86.0% 86.5% 87.0% iMesoSEs cMesoSEs RCP2.6-2055 Managers 2010/2011 Managers RCP2.6-2055 Farmers 2010/2011 Farmers 106 Similar to RCP2.6 pathway, the overall results of the three intervals’ scenarios under RCP6.0 pathway indicate a minor impact on the Sefficiency results, meaning that the WUS will maintain a similar performance at the meso level considering the projected climatic changes under this pathway. Once more, the results clearly show that the increased ET value under such sizeable changes in climatic conditions would not impact the WUS’s performance if it was accompanied by a proportionate increase in groundwater withdrawals. As mentioned earlier, this is expected in a region under water shortage, where higher quantities of withdrawals above the demand are not expected. Nevertheless, the main concern that comes out of our scenario analyses is the sustainability of the main source, the Eastern Aquifer Basin (EAB). Under both pathways, there were substantial increases in abstractions over the consecutive years paralleled with a continuous decrease in precipitation rates. As shown in Figures 6.8 and 6.9, the gap between the increased abstractions from the main source and precipitation, which is the aquifer’s main replenishment source, kept increasing moving forward in time under both RCPs. More importantly, assuming sustaining the same level of agricultural activities, the gap between the main consumptive water use, ET, and the aquifer’s main replenishment source also kept increasing. This combination of changes is substantially damaging for the aquifer’s sustainability. Since 𝑀𝑒𝑠𝑜𝑆𝐸 relates to the interaction between the useful outflow and total flow, such as the WUS’s impact on the downstream users and the effects of its return instances, it will not reflect the WUS’s impact on main source’s sustainability. This is what Macro-Sefficiency (𝑀𝑎𝑐𝑟𝑜𝑆𝐸) is meant to assess. 𝑀𝑎𝑐𝑟𝑜𝑆𝐸 would require measures of water table levels at the beginning and end of the analysis period. Furthermore, the gaps illustrated in Figures 6.8 and 6.9 deliver a message that the region needs a larger (transboundary) scale assessment. The sustainability of EAB would crucially require joint managerial efforts to assess the efficiencies and impacts of the regional WUSs on EAB. Hence, the scale of such an assessment should be wide enough to include other water uses systems that depend on EAB as their main source. 107 Figure 6.8: Percentage change of PP, VA, and ET under RCP2.6 pathway scenarios RCP2.6-2025 RCP2.6-2055 RCP2.6-2090 PP -2 -5 -10 VA 11 15 19 ET 457 -30 -20 -10 0 10 20 30 40 Change (%) Scenario 108 Figure 6.9: Percentage change of PP, VA, and ET under RCP6.0 pathway scenarios RCP6.0-2025 RCP6.0-2055 RCP6.0-2090 PP 0 -10 -20 VA 10 19 30 ET 4 7 10 -30 -20 -10 0 10 20 30 40 Change (%) Scenario 109 CHAPTER SEVEN. CONCLUSIONS AND FUTURE WORKS We will discuss in the final two sections of this thesis the remarks and findings that we can conclude from this study in addition to the recommended future works. This is of a high significance as we consider this research work as a link in the chain of knowledge within the fields of water resources and irrigation management in Palestine rather than a discrete piece. 7.1. Conclusions In regions such as Palestine, the question of water scarcity expands beyond the availability or accessibility of water. Water use systems and the assessment of their efficiency are complex due to the nature of their variables’ dynamics. After applying Sefficiency at meso level (𝑀𝑒𝑠𝑜𝑆𝐸𝑠) in this study, we have reached conclusions that can change, at least, the mindset of the water resources stakeholders in Palestine, especially in irrigation management. The overall results of 𝑀𝑒𝑠𝑜𝑆𝐸𝑠, from the managers’ and farmers’ perspectives considering the inflow and consumption models, have not fallen below 80%. To describe or classify the result into a certain category (e.g. good, satisfactory, poor, and so on) is a management decision based on predefined criteria and objectives. Nevertheless, in a water-scarce region, improvements and efficient water use enhancements are always in need. Additionally, in a future study that includes MacroSE results, we may find out low values at the macro level that demonstrates the need for some fundamental changes in managing water in that part of the world. This study proved that some changes in the three pillars of water management could lead to great impacts on the overall WUS’s performance. To elaborate, improving the quality of return flows for instance, as examined in scenario SC1, has led to substantial changes in the WUS. To begin with, such an improvement can take place through one or a combination of activities such as reducing the use of chemical substances in agriculture and reusing the agricultural wastewater. Each of these actions is, at minimum, a collective effort that encompasses a lot of resources and managerial interventions. Sefficiency results under this scenario indicated how significant an improvement of 𝑊𝑞𝑅𝐹 can be on the overall performance of our WUS. From the managers’ perspective, in both inflow and consumption models, 𝑀𝑒𝑠𝑜𝑆𝐸𝑠 jumped by more than 110 10 percentage points (pp), and from the farmers’ perspective, it jumped by more than 3 pp in both models as well. Although we do not account for the Israeli side’s use in the scope of this study, which is reportedly higher, the meso level and sensitivity analysis results of SC1 demonstrated the impact of chemical substances use on the basin. One of the greatest advantages of adopting Sefficiency is to underline the WUS’s weak points. The number of unreported abstractions is a critical point, which is also a problem in many parts of the world. Despite the PWA’s awareness and acknowledgement of the issue as was confirmed in our interview with Eng. Deeb Abdulghafour, Director-General of Water Resources Management at the Palestinian Water Authority (PWA), and despite the great sensitivity of the issue as he described, we demonstrated how significant it could influence the understanding of the WUS’s performance. In fact, any underestimation of VAUnr values affects Sefficiency results. In all of our hypothesised scenarios, including the six climate change projections, we assumed that the number of unreported abstractions would be as much to satisfy the existing ET values to maintain water balance. Nevertheless, while VAUnr values are unlikely to be lower given the demonstrated analyses, they may well be higher than presented throughout this study, in which case return flows and potential returns maintain water balance. Consequently, the dynamics of the entire system would change, including the usefulness criterion. In order to illustrate that, let us assume that we underestimated the value of VAUnr by 10%, which is the equivalent to the amount of VAPWA increase we hypothesised in SC2. Our analysis of this scenario showed that several consequences will be encountered in the WUS, including a 42% increase in RFEq to maintain water balance accompanied by a change in its 𝑊𝑞 to 0.5. More importantly, it showed that 𝑀𝑒𝑠𝑜𝑆𝐸𝑠 results dropped down by nearly 4 pp from the farmers’ perspective in both inflow and consumption models, which is a significant drop. It has also slightly dropped from the managers’ perspective in both models despite the improvement in 𝑊𝑞𝑅𝐹. The remarkable contrast of 𝑊𝑞𝑅𝐹 improvement’s impact on 𝑀𝑒𝑠𝑜𝑆𝐸𝑠 results between scenarios SC1 and SC2, depending on the reason causing that improvement, is a clear demonstration that the relationship between the different WUS’s variables is not linear, especially when considering the quality and beneficence dimensions of those variables. Furthermore, contrary to what we found in SC2 results, scenario SC3’s analysis proves that an increase in precipitation, which is another form of inflow, could have a noticeable positive impact on 111 𝑀𝑒𝑠𝑜𝑆𝐸𝑠 results. While a 10% increase in VAPWA led to a drop in 𝑀𝑒𝑠𝑜𝑆𝐸𝑠, we found that a 48% increase in PP (to match the long-term average) improved it by more than 2 pp from the managers’ perspective and by more than 1 pp from the farmers’ perspective in both models. This is yet another clear example of the nonlinearity in the systems’ dynamics. Another great advantage of adopting Sefficiency is to highlight the opportunities to enhance the WUS’s sustainability and maximise the benefits according to the defined objectives. For example, scenario SC4 demonstrated the considerable benefit of reducing the unwanted crops (weed) in our WUS (using eco-friendly methods), the selection of high socio-economic value crops, or a combination of both. In our analysis of SC4, we hypothesised that such actions would lead to a 7% increase in 𝑊𝑏𝐸𝑇, a change that resulted in improving 𝑀𝑒𝑠𝑜𝑆𝐸𝑠 considerably by more than 6 pp from both stakeholders’ perspectives in both inflow and consumption models. This last conclusion in particular distinguishes Sefficiency with a unique feature. No other water use efficiency assessment approach can translate policy decisions, field actions, environmental considerations, and socio-economic measures the way Sefficiency does. It facilitates for both stakeholders and WUS’s users a tool and, more importantly, a mindset that helps them achieve the most efficient utilisation of EAB, the main source under consideration. In regards to the potential climate change impacts on temperature and precipitation in the region, our analysis showed a minor effect of those projected changes on 𝑀𝑒𝑠𝑜𝑆𝐸𝑠 results under the six different hypothesised scenarios. For instance, the most sizeable changes are expected to take place within the RCP6.0-2090 scenario, where projections expect the temperature to increase by 3.0°C and precipitation to decrease by 20%. These projections will have dramatic impacts on the different water path instances, such as a 30% increase in VA and a 10% increase in ET consumption. Yet, 𝑀𝑒𝑠𝑜𝑆𝐸𝑠 results from both stakeholders’ perspectives in both inflow and consumption models changed by less than 1 pp. The Sefficiency results of the climate change potential impacts’ within our WUS highlights that the performance at 𝑀𝑒𝑠𝑜𝑆𝐸𝑠 level can be maintained as long as we were able to provide the system with additional abstractions enough to compensate for the increase in ET due to the increase in temperature and decrease in precipitation, and assuming that 𝑊𝑠𝑋 values remain the same. This necessarily means that in order to maintain the same level of agricultural activities and yield production, additional abstractions will be needed, other flows paths are better controlled, or 𝑊𝑠𝑋 values are better adjusted. 112 Correspondingly, supplying additional resources in order to maintain the same yield production in spite of the climate change impacts, if it was possible, would result in possible negative impacts in relation to the basin’s sustainability. However, this does not appear in 𝑀𝑒𝑠𝑜𝑆𝐸𝑠 results because this level of Sefficiency does not reflect the WUS’s impact on the main source. This is 𝑀𝑎𝑐𝑟𝑜𝑆𝐸’s job. 7.2. Recommendations for Future Works As we consider this work as a link in the chain of knowledge in this field rather than a discrete piece, the conclusions that we came across highlight a number of future works that can further complement our efforts. To begin with, the following points explain the areas in which we struggled and what can be done to mitigate that: 1. Agricultural Data in Palestine We selected 2010/2011 season in particular because it is the most recent season for which the Palestinian official sources provide a complete data set that fits the purpose of this study. As we reached the year 2020, a lack of agricultural data is clearly evident in the different Palestinian sources. At the same time as we acknowledge the great efforts of the Palestinian Central Bureau of Statistics, the Palestinian Water Authority, and the Ministry of Agriculture, we can state that the need for additional data collected from the field significantly surpasses these efforts. 2. Water Quality Weights As explained in section 3.3, there are several methods to quantify or score water quality. Besides, we found in this study how significant can the influence of water quality weights be on 𝑀𝑒𝑠𝑜𝑆𝐸𝑠 results (e.g. SC1 scenario results). The application of the previously explained water quality scoring method would require a lot of field quality tests based on the adopted method. Unfortunately, the funding allocated to this research is well below the capacity to perform such tests, and thus we would highly recommend further investigations in this domain. 113 3. Public Participation Since transparency is the core benefit of adopting Sefficiency as a mindset besides being an efficiency assessment method, public participation is a key element in its application. We attempted to reach as many as 40 farmers after spending a lot of time and effort in order to achieve a representable sample of farmers. Yet, there is room to expand this research to include more farmers and other workers in the field of agriculture. Similarly, we managed to interview the Director-General of Water Resources Management at the PWA after a long coordination process, nevertheless, future works can include additional decision-makers, legislators, water resources managers at the local, national, and regional levels. On a different note, any underestimation of the abstracted volumes from EAB, which is a likely situation in our study area, would have a vivid impact on the Sefficiency results and the overall understanding of the water use system. National collective efforts should involve the governmental decision-makers, nongovernmental organisations, researchers and research centres, and the civic community members in order to tackle the unreported abstractions issue. We recommend having these efforts aiming to raise awareness among farmers, improve the technological infrastructure, and enhance public participation in the decision-making process would be a worthy investment. The results of our climate change scenario analysis have highlighted the potential increase in the gap between abstractions, evapotranspiration and precipitation rates under the anticipated climatic changes in the region. Furthermore, during our interview, Eng. Abdulghafour had stressed, more than once, about the negative consequences of the ongoing over-pumping practices and the recently experienced low replenishment rates due to decreased precipitation rates. Therefore addressing the Eastern Aquifer Basin’s sustainability through analysing the relevant water use system(s) on the macro level is extremely needed. We have focused this study only on the agricultural sector in Jericho, which is, by far, the largest use sector among the Eastern Aquifer Basin’s users. Nevertheless, we would recommend a wider analysis that encompasses the different water instances that are flowing in and out of EAB, in addition to its water level at the beginning of the analysis period (VU) and at the end of it (VD), in order to perform macro-level Sefficiency analysis. Such analysis would enable the relevant stakeholders and decision-makers to touch the points where actions are needed. 114 In conclusion, Sefficiency champions transparency. A water balance-based assessment approach is fundamental to reach a thorough understanding of the system’s nature and conclusion about its performance. Additionally, the active participation of all stakeholders involved within the WUS’s boundaries, which constructs a clear definition of water use objectives, enhances the sustainability of our available resources. Joint managerial efforts to assess the performance and impact of the regional water use systems on EAB are crucially important in order to advance its sustainable performance. 115 BIBLIOGRAPHY Adams, Richard M., & Peck, Dannele E. (2008). Effects of Climate Change on Water Resources. CHOICES, 23 (1). Ahmad, M.T., & Haie, N. (2018). Assessing the Impacts of Population Growth and Climate Change on Performance of Water Use Systems and Water Allocation in Kano River Basin, Nigeria. Water, 10 (12). doi:https://doi.org/10.3390/w10121766 Ahmad, Muhammad Tajuri, Haie, Naim, Yen, Haw, & Tuqan, Nasser A. S. (2018). Sefficiency of a Water Use System: The Case of Kano River Irrigation Project, Nigeria. International Journal of Civil Engineering, 16 (8), 929-939. doi:10.1007/s40999-017-0235-2 Al-Jayyousi, O. R. (1999). Rehabilitation of Irrigation Distribution Systems: The Case of Jericho City. Water Resources Management, 13 (2), 117-132. doi:10.1023/A:1008008517186 Al-Juneidi, Faten, & Isaac, Jad. (2000) An assessment of irrigation efficiency in the Palestinian West Bank. Retrieved from: http://www.arij.org/files/admin/1999/1999%20an%20assessment%20of%20irrigation %20efficiency%20in%20the%20palestinian%20west%20bank.pdf. Publisher: ARIJ. Bethlehem, Palestine. Al-Khatib, Nasser, Shoqeir, Jawad Hasan, Özerol, G., & Majaj, Linda. (2017). Governing the reuse of treated wastewater in irrigation: the case study of Jericho, Palestine. International Journal of Global Environmental Issues, 16 , 135-148. Alcamo, Joseph, DÖLl, Petra, Henrichs, Thomas, Kaspar, Frank, Lehner, Bernhard, RÖSch, Thomas, & Siebert, Stefan. (2003). Development and testing of the WaterGAP 2 global model of water use and availability. Hydrological Sciences Journal, 48 (3), 317-337. doi:10.1623/hysj.48.3.317.45290 Allen, Richard G., Clemmens, Albert J., & Willardson, Lyman S. (2005, 10-18 September). Agro-Hydrology and Irrigation Efficiency. Paper presented at the 19th International Cngress on Irrigation and Drainage, Session on Agrohydrology and Efficiency, Beijing, China. Allen, Richard G., Pereira, Luis S., Raes, Dirk, & Smith, Martin. (1998) Crop evapotranspiration - Guidelines for computing crop water requirements - FAO Irrigation and drainage paper 56. Retrieved from: http://www.fao.org/3/x0490e/x0490e00.htm. Publisher: FAO - Food and Agriculture Organization of the United Nations. Rome, Italy. Alsharif, Kamal, Feroz, Ehsan H., Klemer, Andrew, & Raab, Raymond. (2008). Governance of water supply systems in the Palestinian Territories: A data envelopment analysis approach to the management of water resources. Journal of Environmental Management, 87 (1), 80-94. doi:https://doi.org/10.1016/j.jenvman.2007.01.008 AMS. (2019) Glossary of Meteorology. Retrieved from: http://glossary.ametsoc.org/. Publisher: American Meteorological Society. Boston, MA, USA. Accessed on: 07-Aug-2019 122 Kampragou, Eleni, Lekkas, Demetris F., & Assimacopoulos, Dionysis. (2011). Water demand management: implementation principles and indicative case studies. Water and Environment Journal, 25 (4), 466-476. doi:10.1111/j.1747-6593.2010.00240.x Katz, David, & Fischhendler, Itay. (2011). Spatial and temporal dynamics of linkage strategies in Arab–Israeli water negotiations. Political Geography, 30 (1), 13-24. doi:https://doi.org/10.1016/j.polgeo.2010.12.002 Kazem Attar, Hasti, Noory, Hamideh, Ebrahimian, Hamed, & Liaghat, Abdol-Majid. (2020). Efficiency and productivity of irrigation water based on water balance considering quality of return flows. Agricultural Water Management, 231 , 106025. doi:https://doi.org/10.1016/j.agwat.2020.106025 Keller, Andrew A., & Keller, Jack. (1995) Effective Efficiency: A Water Use Efficiency Concept for Allocating Freshwater Resources. Retrieved from: Publisher: Center for Economic Policy Studies - Winrock International. Discussion Paper 22. North Kent St., Arlington VA, USA. Kenyon, Kathleen M. (1954). ANCIENT JERICHO. Scientific American, 190 (4), 76-83. Klawitter, Simone. (2007). Water as a Human Right: The Understanding of Water Rights in Palestine. International Journal of Water Resources Development, 23 (2), 303-327. doi:10.1080/07900620601181697 Kliot, Nurit, & Shmueli, Deborah. (1998). Real and Ideal Institutional Frameworks for Managing the Common Arab-Israeli Water Resources. Water International, 23 (4), 216-226. doi:10.1080/02508069808686775 Kondili, E., Kaldellis, J. K., & Papapostolou, C. (2010). A novel systemic approach to water resources optimisation in areas with limited water resources. Desalination, 250 (1), 297-301. doi:https://doi.org/10.1016/j.desal.2009.09.046 Kruse, E. Gordon. (1978). Describing Irrigation Efficiency and Uniformity. 104 (1). La Jeunesse, I., Cirelli, C., Aubin, D., Larrue, C., Sellami, H., Afifi, S., . . . Soddu, A. (2016). Is climate change a threat for water uses in the Mediterranean region? Results from a survey at local scale. Science of The Total Environment, 543 , 981-996. doi:https://doi.org/10.1016/j.scitotenv.2015.04.062 Lankford, Bruce A. (2008). Integrated, adaptive and domanial water resources management (Book Section). In C. Pahl-Wostl, P. Kabat, & J. Möltgen (Eds.), Adaptive and Integrated Water Management (pp. 39-59). Berlin, Germany: Springer-Verlag Berlin Heidelberg. doi:10.1007/978-3-540-75941-6 Lautze, J., & Kirshen, P. (2009). Water allocation, climate change, and sustainable water use in Israel/Palestine: the Palestinian position. Water International, 34 (2), 189-203. doi:10.1080/02508060902903175 123 Lautze, Jonathan, Reeves, Meredith, Vega, Rosaura, & Kirshen, Paul. (2005). Water Allocation, Climate Change, and Sustainable Peace The Israeli Proposal. Water International, 30 (2), 197-209. doi:10.1080/02508060508691860 Lazarou, Elena. (2016) Briefing - Water in the Israeli-Palestinian conflict. Retrieved from: http://www.europarl.europa.eu/RegData/etudes/BRIE/2016/573916/EPRS_BRI%28 2016%29573916_EN.pdf. Publisher: European Union. Brussels, Belgium. Leavesley, George H. (1994). Modeling the effects of climate change on water resources - a review. Climatic Change, 28 (1), 159-177. doi:10.1007/BF01094105 Liu, Haijun, Wang, Xuming, Zhang, Xian, Zhang, Liwei, Li, Yan, & Huang, Guanhua. (2017). Evaluation on the responses of maize (Zea mays L.) growth, yield and water use efficiency to drip irrigation water under mulch condition in the Hetao irrigation District of China. Agricultural Water Management, 179 , 144-157. doi:https://doi.org/10.1016/j.agwat.2016.05.031 Lowi, M. R. (1993). Bridging the Divide - Transboundary Resource Disputes and the Case of West-Bank Water. International Security, 18 (1), 113-138. doi:Doi 10.2307/2539034 Lumb, Ashok, Sharma, T. C., & Bibeault, Jean-François. (2011). A Review of Genesis and Evolution of Water Quality Index (WQI) and Some Future Directions. Water Quality, Exposure and Health, 3 (1), 11-24. doi:10.1007/s12403-011-0040-0 Martínez, J., & Reca, J. (2014). Water Use Efficiency of Surface Drip Irrigation versus an Alternative Subsurface Drip Irrigation Method. 140 (10), 04014030. doi:doi:10.1061/(ASCE)IR.1943-4774.0000745 Mason, Michael. (2013). Climate change, securitisation and the Israeli–Palestinian conflict. 179 (4), 298-308. doi:10.1111/geoj.12007 Masui, Toshihiko, Matsumoto, Kenichi, Hijioka, Yasuaki, Kinoshita, Tsuguki, Nozawa, Toru, Ishiwatari, Sawako, . . . Kainuma, Mikiko. (2011). An emission pathway for stabilization at 6 Wm−2 radiative forcing. Climatic Change, 109 (1), 59. doi:10.1007/s10584-0110150-5 McNeill, L. S., Almasri, M. N., & Mizyed, N. (2009). A sustainable approach for reusing treated wastewater in agricultural irrigation in the West Bank – Palestine. Desalination, 248 (1), 315-321. doi:https://doi.org/10.1016/j.desal.2008.05.070 Messerschmid, Clemens. (2012). Nothing New in the Middle East – Reality and Discourses of Climate Change in the Israeli-Palestinian Conflict (Book Section). In J. Scheffran, M. Brzoska, H. G. Brauch, P. M. Link, & J. Schilling (Eds.), Climate Change, Human Security and Violent Conflict: Challenges for Societal Stability (pp. 423-459). Berlin, Germany: Springer Berlin Heidelberg. doi:10.1007/978-3-642-28626-1_22 Mimi, Z. A., Ziara, M., & Nigim, H. H. (2003). WATER CONSERVATION AND ITS PERCEPTION IN PALESTINE: A CASE STUDY. 17 (3), 152-156. doi:10.1111/j.17476593.2003.tb00453.x 124 Mimi, Ziad A., & Abu Jamous, Sireen. (2010). Climate change and agricultural water demand: Impacts and adaptations. African Journal of Environmental Science and Technology, 4(4) , 183-191. doi:10.5897/AJEST09.174 Mizyed, Numan. (2009). Impacts of Climate Change on Water Resources Availability and Agricultural Water Demand in the West Bank. Water Resources Management, 23 (10), 2015-2029. doi:10.1007/s11269-008-9367-0 Mizyed, Numan. (2018). Climate Change Challenges to Groundwater Resources: Palestine as a Case Study. Journal of Water Resource and Protection, 10 (02), 15. doi:10.4236/jwarp.2018.102013 MOPIC. (1998) Emergency Natural Resources Protection Plan for Palestine "West Bank Governorates". Retrieved from: Publisher: Ministry of Planning and International Cooperation (MOPIC). Ramallah, Palestine. OCHA. (2012) Humanitarian Fact Sheet on the Jordan Valley and Dead Sea Area. Retrieved from: https://www.ochaopt.org/sites/default/files/ocha_opt_jordan_valley_factSheet_febru ary_2012_english.pdf. Publisher: United Nations Office for the Coordination of Humanitarian Affairs (OCHA). Jerusalem, Palestine. Onta, Pushpa R., Loof, Rainer, & Banskota, Madhab. (1995). Performance based irrigation planning under water shortage. Irrigation and Drainage Systems, 9 (2), 143-162. doi:10.1007/BF00881673 Pahl-Wostl, Claudia. (2007). Transitions towards adaptive management of water facing climate and global change. Water Resources Management, 21 (1), 49-62. doi:10.1007/s11269-006-9040-4 PCBS. (2010) Metrological Tables - Year 2009. Retrieved from: http://www.pcbs.gov.ps/site/lang__en/1029/Default.aspx. Publisher: Palestinian Central Bureau of Statistics (PCBS). Ramallah, Palestine. Accessed on: 25 April 2020 PCBS. (2012) Agricultural Census 2010 Final Results – Jericho & Al Aghwar Governorate. Retrieved from: http://www.pcbs.gov.ps/Downloads/book1836.pdf. Publisher: Palestinian Central Bureau of Statistics (PCBS). Ramallah, Palestine. PCBS. (2016) Agriculture Statistics. Retrieved from: http://www.pcbs.gov.ps/PCBS_2012/Publications.aspx?CatId=1&scatId=239. Publisher: Palestinian Central Bureau of Statistics (PCBS). Ramallah, Palestine. Accessed on: 14 March 2020 PCBS. (2018) Preliminary results of the general census of population, housing and establishments 2017. Retrieved from: http://www.pcbs.gov.ps/Downloads/book2364.pdf. Publisher: Palestinian Central Bureau of Statistics (PCBS). Ramallah, Palestine. PCBS. (2019) Annual Rainfall Quantity (mm) in the West Bank by Station Location and Year, 2010-2018 Retrieved from: 125 http://www.pcbs.gov.ps/Portals/_Rainbow/Documents/Metrological-2018-04E.html. Publisher: Palestinian Central Bureau of Statistics (PCBS). Ramallah, Palestine. Accessed on: 05 February 2020 PCBS. (2020) Annual Statistics. Retrieved from: http://www.pcbs.gov.ps/site/lang__en/803/default.aspx. Publisher: Palestinian Central Bureau of Statistics (PCBS). Ramallah, Palestine. Accessed on: 02 February 2020 PCBS, & PWA. (2019) Press Release on the Occasion of World Water Day, March 22nd, 2019. Retrieved from: http://www.pcbs.gov.ps/portals/_pcbs/PressRelease/Press_En_21-32019-water-en.pdf. Publisher: The Palestinian Central Bureau of Statistics (PCBS). Ramallah, Palestine. Pereira, Luis S., Cordery, Ian, & Iacovides, Iacovos. (2012). Improved indicators of water use performance and productivity for sustainable water conservation and saving. Agricultural Water Management, 108 , 39-51. doi:https://doi.org/10.1016/j.agwat.2011.08.022 Piao, Shilong, Ciais, Philippe, Huang, Yao, Shen, Zehao, Peng, Shushi, Li, Junsheng, . . . Fang, Jingyun. (2010). The impacts of climate change on water resources and agriculture in China. Nature, 467 (7311), 43-51. doi:10.1038/nature09364 Priscoli, Jerome Delli. (2004). What is Public Participation in Water Resources Management and Why is it Important? Water International, 29 (2), 221-227. doi:10.1080/02508060408691771 PWA. (2012) Annual Status Report on water resources, Water Supply, and Wastewater in the Occupied State of Palestine 2011. Retrieved from: http://pwa.ps/userfiles/file/%D8%AA%D9%82%D8%A7%D8%B1%D9%8A%D8%B1/Annu al%20Water%20Status%20report%202011.pdf. Publisher: Palestinian Water Authority. Ramallah, Palestine. PWA. (2013) Status Report of Water Resorces in the Occupied State of Palestine - 2012. Retrieved from: http://www.pwa.ps/userfiles/file/%D8%AA%D9%82%D8%A7%D8%B1%D9%8A%D8%B1/ %D8%AA%D8%B5%D9%86%D9%8A%D9%81%201/WR%20STATUS%20Reportfinal%20draft%202014-04-01.pdf. Publisher: Palestinian Water Authority. Ramallah, Palestine. PWA. (2014) Strategic Water Resource and Transmission Plan. Retrieved from: http://www.pwa.ps/userfiles/server/%D8%A7%D8%B3%D8%AA%D8%B1%D8%A7%D8%A A%D8%AC%D9%8A%D8%A7%D8%AA/Strategic%20Action%20Plan%20(1).pdf. Publisher: Palestinian Water Authority. Ramallah, Palestine. PWA. (2016) Water Sector Reform Plan 2016-2018. Retrieved from: http://www.pwa.ps/userfiles/server/%D8%A7%D8%B3%D8%AA%D8%B1%D8%A7%D8%A A%D8%AC%D9%8A%D8%A7%D8%AA/Water%20Sector%20Reform%20Plan%2020162018.pdf. Publisher: Palestinian Water Authority. Ramallah, Palestine. 126 PWA. (2017) Groundwater Resources - Utilization 2015. Retrieved from: http://www.pwa.ps/page.aspx?id=NL8EMVa2547842781aNL8EMV. Publisher: Palestinian Water Authority. Ramallah, Palestine. Accessed on: 05 July 2019 PWA. (2018) Water Resources in Palestine. Retrieved from: http://pwa.ps/ar_page.aspx?id=rcF7YCa2566877841arcF7YC. Publisher: Palestinian Water Authority. Ramallah, Palestine. Accessed on: 15 July 2019 Qin, Changbo, Su, Z., Bressers, Hans Th A., Jia, Yangwen, & Wang, Hao. (2013). Assessing the economic impact of North China’s water scarcity mitigation strategy: a multi-region, water-extended computable general equilibrium analysis. Water International, 38 (6), 701-723. doi:10.1080/02508060.2013.823070 Qtaishat, Tala. (2013). Impact of Water Reallocation on the Economy in the Fertile Crescent. Water Resources Management, 27 (10), 3765-3774. doi:10.1007/s11269-013-0379-z Rahil, M. H., & Qanadillo, A. (2015). Effects of different irrigation regimes on yield and water use efficiency of cucumber crop. Agricultural Water Management, 148 , 10-15. doi:https://doi.org/10.1016/j.agwat.2014.09.005 Ronen, Yaël. (2014). Israel, Palestine and the ICC — Territory Uncharted but not Unknown. Journal of International Criminal Justice, 12 (1), 7-25. doi:10.1093/jicj/mqu006 Rosegrant, Mark W., & Ringler, Claudia. (1999) Impact on Food Security and Rural Development of Reallocating Water from Agriculture. Retrieved from: http://ageconsearch.umn.edu/record/97500/files/eptdp47.pdf. Publisher: AgEcon Search. EPTD Discussion Paper No. 47, International Food Policy Research Institute, Washington D.C., USA. doi:10.22004/ag.econ.97500 Russell, Sally, & Fielding, Kelly. (2010). Water demand management research: A psychological perspective. Water Resources Research, 46 (5). doi:10.1029/2009WR008408 Savenije, Hubert H. G., & van der Zaag, Pieter. (2002). Water as an Economic Good and Demand Management Paradigms with Pitfalls. Water International, 27 (1), 98-104. doi:10.1080/02508060208686982 Selby, Jan. (2003). Dressing up domination as ‘cooperation’: the case of Israeli-Palestinian water relations. Review of International Studies, 29 (1), 121-138. doi:10.1017/S026021050300007X Selby, Jan. (2007). Joint Mismanagement: Reappraising the Oslo Water Regime (Book Section). In H. Shuval & H. Dweik (Eds.), Water Resources in the Middle East: Israel-Palestinian Water Issues — From Conflict to Cooperation (pp. 203-212). Berlin, Heidelberg: Springer Berlin Heidelberg. doi:10.1007/978-3-540-69509-7_20 Selby, Jan. (2013). Cooperation, domination and colonisation: the Israeli-Palestinian Joint Water Committee. Water Alternatives, 6 (1), 1-24. Seung, Chang K., Harris, Thomas R., Englin, Jeffrey E., & Netusil, Noelwah R. (2000). Impacts of water reallocation: A combined computable general equilibrium and recreation 127 demand model approach. The Annals of Regional Science, 34 (4), 473-487. doi:10.1007/s001689900011 Seung, Chang K., Harris, Thomas R., & MacDiarmid, Thomas R. (1998). Economic impacts of surface water reallocation policies: A comparison of supply-determined SAM and CGE models. The Journal of Regional Analysis & Policy, 28 (2), 13-34. Shamir, Uri. (1998). Water Agreements Between Israel and Its Neighbors (Book Section). In M. B. Jeff Albert, Roger Kenna (Ed.), Transformations of Middle Eastern Natural Environments: Legacies and Lessons (103 ed.). Yale School of Forestry and Environmental Studies: Yale University, New Haven, Connecticut, USA Shevah, Y. (2017). Chapter Six - Challenges and Solutions to Water Problems in the Middle East (Book Section). In S. Ahuja (Ed.), Chemistry and Water (pp. 207-258): Elsevier. doi:https://doi.org/10.1016/B978-0-12-809330-6.00006-4 Shiklomanov, Igor A. (1998) World water resources: a new appraisal and assessment for the 21st century : a summary of the monograph world water resources. Retrieved from: Publisher: UNESCO International Hydrological Programme (UNESCO-IHP). Paris, France. Slaughter, A.R., Mantel, S.K., & Hughes, D.A. (2014). Investigating possible climate change and development effects on water quality within an arid catchment in South Africa: A comparison of two models. Paper presented at the 7th International Congress on Environmental Modelling and Software, iEMSs 2014, San Diego; CA. Small, Leslie E., & Rimal, Arbindra. (1996). Effects of alternative water distribution rules on irrigation system performance: a simulation analysis. Irrigation and Drainage Systems, 10 (1), 25-45. doi:10.1007/BF01102763 Smith, M. (1992) CROPWAT: A Computer Program for Irrigation Planning and Management (Book). Publisher: Food and Agriculture Organization of the United Nations (FAO). Rome, Italy Smithers, Richard, Harrison, Mike, Mimi, Ziad, Hardan, Khaled, Abdelall, Sadiq, & Hasan, Afif. (2016) National Adaptation Plan (NAP) to Climate Change. Retrieved from: https://www4.unfccc.int/sites/NAPC/Documents%20NAP/National%20Reports/State% 20of%20Palestine%20NAP.pdf. Publisher: Environment Quality Authority (EQA). Ramallah, Palestine. Solomon, K. H., & Burt, C. M. (1999). Irrigation sagacity: a measure of prudent water use. Irrigation Science, 18 (3), 135-140. doi:10.1007/s002710050054 Sowers, Jeannie, Vengosh, Avner, & Weinthal, Erika %J Climatic Change. (2011). Climate change, water resources, and the politics of adaptation in the Middle East and North Africa. 104 (3), 599-627. doi:10.1007/s10584-010-9835-4 Stankey, George H., Clark, Roger N., & Bormann, Bernard T. (2005) Adaptive Management of Natural Resources: Theory, Concepts, and Management Institutions. Retrieved from: 128 Publisher: United States Department of Agriculture - Forest Service - Pacific Northwest Research Station. Portland, OR, USA. doi:https://doi.org/10.2737/PNW-GTR-654 Tal-Spiro, Ori. (2011) Israeli-Palestinian Cooperation on Water Issues. Retrieved from: https://m.knesset.gov.il/EN/activity/mmm/me02767.pdf. Publisher: The Knesset: The Research and Information Center - Center for Research and Information Kiryay Ben Gurion. Jerusalem, Israel. Tortajada, Cecilia, & Joshi, Yugal K. (2013). Water Demand Management in Singapore: Involving the Public. Water Resources Management, 27 (8), 2729-2746. doi:10.1007/s11269-013-0312-5 Tuqan, Nasser, Haie, Naim, & Ahmad, Muhammad Tajuri. (2020). Assessment of the Agricultural Water Use in Jericho Governorate Using Sefficiency. Sustainability, 12 (9), 1-18. doi:https://doi.org/10.3390/su12093634 UN-ESCWA, & BGR. (2013). Chapter 6: Jordan River Basin (Book Section). In Inventory of Shared Water Resources in Western Asia . Beirut, Lebanon: UN-ESCWA (United Nations Economic and Social Commission for Western Asia) and BGR (Bundesanstalt für Geowissenschaften und Rohstoffe) UNCTAD. (2015) The Besieged Palestinian Agricultural Sector. Retrieved from: https://unctad.org/en/PublicationsLibrary/gdsapp2015d1_en.pdf. Publisher: United Nations Conference on Trade and Development (UNCTAD). New York, NY, USA and Geneva, Switzerland. UNESCO-IHP. (2014) Water in the post-2015 development agenda and sustainable development goals. Retrieved from: https://en.unesco.org/events/water-post-2015development-agenda-and-sustainable-development-goals. Publisher: UNESCO International Hydrological Programme (UNESCO-IHP). Paris, France. United Nations Statistics Division. (2012) Demographic Yearbook: Table 3, Population by sex, annual rate of population increase, surface area and density. Retrieved from: https://unstats.un.org/unsd/demographic/products/dyb/dyb2012/Table03.pdf. Publisher: United Nations. New York, NY, USA. van Vuuren, Detlef P., Edmonds, Jae, Kainuma, Mikiko, Riahi, Keywan, Thomson, Allison, Hibbard, Kathy, . . . Rose, Steven K. (2011). The representative concentration pathways: an overview. Climatic Change, 109 (1), 5. doi:10.1007/s10584-011-0148-z van Vuuren, Detlef P., Stehfest, Elke, den Elzen, Michel G. J., Kram, Tom, van Vliet, Jasper, Deetman, Sebastiaan, . . . van Ruijven, Bas. (2011). RCP2.6: exploring the possibility to keep global mean temperature increase below 2°C. Climatic Change, 109 (1), 95. doi:10.1007/s10584-011-0152-3 Vörösmarty, C. J., McIntyre, P. B., Gessner, M. O., Dudgeon, D., Prusevich, A., Green, P., . . . Davies, P. M. (2010). Global threats to human water security and river biodiversity. Nature, 467 (7315), 555–561. doi:https://doi.org/10.1038/nature09440 129 Vörösmarty, Charles J., Green, Pamela, Salisbury, Joseph, & Lammers, Richard B. (2000). Global Water Resources: Vulnerability from Climate Change and Population Growth. Science, 289 (5477), 284-288. doi:10.1126/science.289.5477.284 WAFA. (2015) Palestinian part of Jordan Valley. Retrieved from: http://info.wafa.ps/ar_page.aspx?id=9663. Publisher: Palestinian News and Info Agency (WAFA). Ramallah, Palestine. Accessed on: 18 January 2019 Warren, Andrew J., & Holman, Ian P. (2012). Evaluating the effects of climate change on the water resources for the city of Birmingham, UK. Water and Environment Journal, 26 (3), 361-370. doi:10.1111/j.1747-6593.2011.00296.x Washington, W. M., Weatherly, J. W., Meehl, G. A., Semtner Jr, A. J., Bettge, T. W., Craig, A. P., . . . Zhang, Y. (2000). Parallel climate model (PCM) control and transient simulations. Climate Dynamics, 16 (10), 755-774. doi:10.1007/s003820000079 Weber, Marian L. (2001). Markets for Water Rights under Environmental Constraints. Journal of Environmental Economics and Management, 42 (1), 53-64. doi:https://doi.org/10.1006/jeem.2000.1149 Willardson, L. S., Allen, R. G., & Frederiksen, H. D. (1994). Elimination of Irrigation Efficiencies . Paper presented at the Irrigation Planning and Management Measures in Harmony with the Environment session, 13th Technical Conference, United States Committee on Irrigation and Drainage (USCID). Denver, CO, USA. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.491.7241&rep=rep1&type =pdf Williams, B. K., Szaro, Robert C., & Shapiro, Carl D. (2009) Adaptive management: The U.S. Department of the Interior technical guide. Retrieved from: http://pubs.er.usgs.gov/publication/70194537. Publisher: U. S. Department of the Interior. Washington, D.C., USA. Wood, Andrew W., Lettenmaier, Dennis P., & Palmer, Richard N. (1997). Assessing Climate Change Implications for Water Resources Planning. Climatic Change, 37 (1), 203-228. doi:10.1023/A:1005380706253 World Bank. (2009) West Bank and Gaza - Assessment of Restrictions on Palestinian Water Sector Development (English). Retrieved from: http://documents.worldbank.org/curated/en/775491468139782240/West-Bank-andGaza-Assessment-of-restrictions-on-Palestinian-water-sector-development. Publisher: World Bank Group. Washington, D.C., USA. World Bank. (2012) Fiscal Crisis, Economic Prospects - The Imperative for Economic Cohesion in the Palestinian Territories. Retrieved from: http://documents.worldbank.org/curated/en/350371468141891355/pdf/760230W P0GZ0AH02Box374357B00PUBLIC0.pdf. Publisher: World Bank Group. Washington, D.C., USA. WWAP, & UNESCO Director-General. (2014) The United Nations World Water Development Report 2014. R. Connor & E. Koncagül (Ed.) Retrieved from: 130 http://www.unesco.org/new/en/naturalsciences/environment/water/wwap/wwdr/2014-water-and-energy/. Publisher: United Nations World Water Assessment Programme (WWAP) & UNESCO. Paris, France. WWAP, & UNESCO Director-General. (2019) The United Nations World Water Development Report 2019: Leaving No One Behind. Retrieved from: https://en.unesco.org/themes/water-security/wwap/wwdr/2019. Publisher: United Nations World Water Assessment Programme (WWAP) & UNESCO. Paris, France. Yamout, G., & El-Fadel, M. (2005). An Optimization Approach for Multi-Sectoral Water Supply Management in the Greater Beirut Area. Water Resources Management, 19 (6), 791812. doi:10.1007/s11269-005-3280-6 Yue, Derek P. T., & Tang, S. L. (2011). Sustainable strategies on water supply management in Hong Kong. 25 (2), 192-199. doi:10.1111/j.1747-6593.2009.00209.x Zeitoun, Mark, Messerschmid, Clemens, & Attili, Shaddad. (2008). Asymmetric Abstraction and Allocation: The Israeli-Palestinian Water Pumping Record. Ground water, 47 , 146-160. doi:10.1111/j.1745-6584.2008.00487.x Zhou, Qing, Deng, Xiangzheng, Wu, Feng, Li, Zhihui, & Song, Wei. (2017). Participatory Irrigation Management and Irrigation Water Use Efficiency in Maize Production: Evidence from Zhangye City, Northwestern China. Water, 9 (11). doi:10.3390/w9110822 131 SCIENTIFIC OUTPUT 1. Tuqan, N.; Haie, N.; Ahmad, M.T. Assessment of the Agricultural Water Use in Jericho Governorate Using Sefficiency. Sustainability 2020, 12, 3634. Link (open access): https://www.mdpi.com/2071-1050/12/9/3634 2. Ahmad, M.T., Haie, N., Yen, H. and Tuqan, N.A.S. (2018) Sefficiency of a Water Use System: The Case of Kano River Irrigation Project, Nigeria. International Journal of Civil Engineering 16(8), 929-939. Link: https://link.springer.com/article/10.1007/s40999-017-0235-2 3. Tuqan, N.; Haie, N. Climate Change Impacts on Sefficiency of the Agricultural Water Use in Jericho Governorate (under preparation).