LONG-TERM DYNAMICS OF ATMOSPHERIC PRECIPITATION IN THE SANGZAR–BAKHMAL REGION (2000–2024)

SCIENCE AND INNOVATION INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 4 ISSUE 10 OCTOBER 2025 ISSN: 2181-3337 | SCIENTISTS.UZ 39 LONG-TERM DYNAMICS OF ATMOSPHERIC PRECIPITATION IN THE SANGZAR–BAKHMAL REGION (2000–2024) B.О. Shermanov Alfraganus University, Uzbekistan, Tashkent, Yunusabad district, st. Yukori Karakamysh, 2A https://doi.org/10.5281/zenodo.17463457 Abstract. This paper presents the results of a long-term analysis of atmospheric precipitation data for the period 2000–2024 in the Sangzar–Bakhmal region. The seasonal and interannual distribution of moisture was assessed, and climatic trends and periods of aridization were identified. The annual amount of precipitation varied from 370.8 mm to 626.7 mm, with an average value of 530.9 mm. The majority of precipitation occurs during the spring–winter period. The results are significant for forecasting agro-climatic conditions, assessing water resources, and ensuring rational land use. Keywords: precipitation, climate, seasonality, variation, Sangzar–Bakhmal, water balance, moisture. Introduction Climatic changes observed over the past few decades have had a profound impact on the hydrometeorological regime of the foothill territories of Central Asia. These regions, situated at the transition between arid plains and mountain systems, are among the most sensitive indicators of global and regional climate fluctuations. Variations in atmospheric circulation, increased temperature anomalies, and shifts in precipitation patterns have led to changes in water availability, soil moisture, and the productivity of agro-ecosystems. For Uzbekistan, where the agricultural sector remains the backbone of the national economy, such transformations have a direct effect on food security, irrigation management, and land productivity. Understanding the long-term dynamics of atmospheric precipitation is therefore essential for the sustainable management of natural resources, as rainfall remains the primary source of soil and groundwater replenishment in non-irrigated territories. The Sangzar–Bakhmal region, located in the foothill zone of Jizzakh region, represents a key area for studying regional climatic variability. The area’s complex orographic structure, encompassing mountain slopes, valleys, and intermountain depressions, generates significant spatial contrasts in temperature and humidity. These geomorphological conditions influence the intensity and distribution of precipitation, forming unique local microclimates. Long-term observation and statistical analysis of precipitation in this region enable researchers to identify periodic fluctuations, long-term trends of aridization or humidification, and their relationship to broader atmospheric circulation patterns, such as the Mediterranean cyclonic activity and Central Asian anticyclonic influence. Furthermore, the Sangzar–Bakhmal region serves as an important natural laboratory for assessing the impact of climate variability on water balance, erosion processes, and pasture productivity. In recent decades, increasing irregularity of rainfall, combined with anthropogenic pressures such as overgrazing and land conversion, has intensified soil degradation and reduced ecosystem resilience. SCIENCE AND INNOVATION INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 4 ISSUE 10 OCTOBER 2025 ISSN: 2181-3337 | SCIENTISTS.UZ 40 Comprehensive monitoring of precipitation dynamics not only provides insights into the hydroclimatic stability of the region but also contributes to the development of predictive models for climate adaptation in agriculture. Such research is crucial for rational water resource management, optimization of crop structure, and implementation of climate-resilient farming systems in Uzbekistan’s foothill landscapes. In this context, the present study aims to analyze the long-term dynamics of atmospheric precipitation in the Sangzar–Bakhmal region over the 25-year period from 2000 to 2024, to determine seasonal and interannual variations, identify phases of aridization and humidification, and provide a scientific basis for improving agroclimatic planning and land management under the changing climate conditions of Central Asia. Literature Review The study of precipitation variability and soil moisture dynamics in the foothill and mountainous regions of Central Asia has become a key direction in modern climate and geoecological research. These areas are particularly sensitive to global and regional climatic shifts, as even small fluctuations in precipitation significantly affect soil fertility, vegetation productivity, and land degradation processes. Regional Research in Uzbekistan A number of recent Uzbek studies have addressed the issues of land degradation and its relationship with climatic and hydrological factors. According to Niyazmetov U.Kh. and Tozhiev Z.T. (2025), the degradation of foothill rainfed lands in Uzbekistan is directly associated with a decrease in atmospheric moisture and the intensification of erosion [1]. The authors emphasize the importance of protecting soil cover through organic matter restoration and water conservation practices. Similarly, Voitov A.B. et al. (2023) point out that the degradation of pastures and the spread of desertification are consequences of both anthropogenic pressure and climatic aridization [2]. Their methodological guidelines propose a system of sustainable land management and monitoring measures for arid ecosystems. The studies by Parpiev G.T. et al. (2022) focus on improving the fertility of irrigated loess soils by regulating moisture balance and nutrient content, while Ruzmetov M.I. (2023) highlights the cyclic character of climatic oscillations in Jizzakh Region, identifying alternating wet and dry periods with an 8–12-year frequency. These findings underline the importance of long-term climatic observation for predicting soil productivity and degradation risks [3,4]. Further evidence is provided by Turaev R.A. and Davronov O.O. (2021), who documented an increasing amplitude of annual precipitation variability in the foothill areas of Central Uzbekistan [5]. They report that the contrast between wet and dry seasons is becoming more pronounced, resulting in irregular vegetation growth and enhanced erosion. At the same time, Norkulov M.N. (2023) and Sharopov R.N. (2023) underline the role of modern technologies such as remote sensing (RS) and geographic information systems (GIS) for continuous monitoring of moisture dynamics and pasture conditions. Their PhD research demonstrates how automated observation systems and spatial modeling improve the precision of climatic and land-use assessment [6,7]. Overall, Uzbek scientific literature confirms that land degradation and the hydrometeorological instability of the Sangzar–Bakhmal and other foothill regions stem from a combination of natural climatic variability and human-induced land mismanagement. The prevailing trend toward aridization calls for systematic observation and adaptation strategies. International Research on Precipitation Dynamics At the global and regional level, several studies provide essential insights into the temporal variability and drivers of precipitation in arid Central Asia. Ding D.G. et al. (2023) reconstructed SCIENCE AND INNOVATION INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 4 ISSUE 10 OCTOBER 2025 ISSN: 2181-3337 | SCIENTISTS.UZ 41 precipitation records from the Pamir Plateau over the past 2500 years, revealing alternating phases of humidification and aridization [8]. These long-term oscillations contextualize the modern precipitation decline within broader paleoclimatic cycles. Similarly, Jiang J. et al. (2021) in Journal of Climate demonstrated that precipitation variability in Central Asia is strongly influenced by tropical Pacific conditions (ENSO and PDO phases), highlighting the teleconnection between remote oceanic processes and regional hydroclimate [9,20]. Chen J. et al. (2022) analyzed daily precipitation extremes across Central Asia, identifying clear spatial trends toward more frequent short-term heavy rains [10]. These events, while increasing annual totals in some regions, also contribute to soil erosion and runoff instability. A related study by Feng K. et al. (2025) confirmed that Central Asia experiences intensified drought cycles and hydrological imbalance, driven by changes in large-scale atmospheric circulation and rising temperatures [12]. Guo C. et al. (2025) examined the spatiotemporal characteristics of extreme precipitation events and found that the foothill areas of Uzbekistan and southern Kazakhstan display a “bimodal” precipitation regime, with wet springs and dry summers. This pattern is consistent with observations from the Sangzar–Bakhmal region and supports the classification of the local climate as semi-arid continental with strong seasonality [11,12]. The assessment by Zhu Z. et al. (2025) in Earth’s Future applied an environmental sustainability framework to the entire Central Asian arid belt, concluding that water scarcity and land degradation are closely interlinked phenomena that require integrated management approaches combining hydrology, land use, and climate policy [13]. Remote Sensing and GIS Applications in Monitoring Moisture and Land Degradation Modern research also highlights the crucial role of geospatial technologies in quantifying and monitoring precipitation-related processes. Sodikova G. et al. (2025) conducted a GIS-based assessment of soil erosion in Uzbekistan’s mountain and rainfed territories, identifying critical zones of degradation through the integration of terrain, vegetation, and hydrological data layers [14]. Similarly, Khazieva E. et al. (2023) proposed a multi-data approach combining satellite imagery and field surveys to assess progress toward land degradation neutrality (LDN), offering a framework that can be adapted for the Sangzar–Bakhmal region [15]. These approaches align closely with the findings of Sharopov R.N. (2023), who suggested that the implementation of automated monitoring stations in Uzbekistan’s foothill regions would enable real-time climate analysis and early warning of drought conditions [7,20]. Climatic Drivers and Teleconnections Several studies have identified global atmospheric drivers affecting the hydroclimate of Central Asia. Chen Z. et al. (2022) revealed that precipitation response differs markedly between strong and weak El Niño events, which modify the westerly jet and moisture inflow patterns across Central Asia [16]. Khadgarai S. et al. (2021) and Gummadi S. et al. (2025) further demonstrated that extreme precipitation variability correlates with shifts in large-scale circulation indices such as the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) [17,18]. These findings provide a physical explanation for the multi-phase precipitation trends (2000–2009, 2010–2016, 2017–2024) observed in the Sangzar–Bakhmal data, suggesting that global atmospheric teleconnections are the underlying cause of regional moisture fluctuations. Summary of Research Gaps Despite the growing body of literature, several gaps remain evident: 1. Limited integration of regional and global data: Uzbek research focuses mainly on local land degradation without linking it to broader atmospheric circulation patterns. SCIENCE AND INNOVATION INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 4 ISSUE 10 OCTOBER 2025 ISSN: 2181-3337 | SCIENTISTS.UZ 42 2. Insufficient temporal continuity: Many studies cover short (10–15 year) observation periods, which complicates long-term trend analysis. 3. Need for applied hydrological modeling: Few works simulate future precipitation scenarios or estimate their impact on agricultural productivity. 4. Underutilization of combined methods: Integrating bio-geochemical, remote sensing, and field monitoring data remains an emerging task for climate resilience strategies. Conclusion of the Literature Review In summary, the reviewed literature demonstrates that precipitation variability and land degradation in Uzbekistan’s foothill regions are shaped by the interaction of regional climatic dynamics and global teleconnection systems. Local studies confirm the trend toward seasonal asymmetry and increasing interannual variation, while international research explains these phenomena through large-scale atmospheric mechanisms. To advance this field, future research should focus on multi-scale monitoring, climate modeling, and adaptive land management, ensuring the sustainable development of mountain and foothill ecosystems under conditions of global climate change. Materials and Methods The present study is based on the observational data from the Sangzar–Bakhmal meteorological station (Jizzakh region, Uzbekistan) for the period 2000–2024 (25 years). The dataset includes monthly and annual totals of atmospheric precipitation, recorded according to the standards of the Uzbekistan Hydrometeorological Service (Uzhydromet). A comprehensive statistical analysis of climatic time series was conducted using both descriptive and inferential methods, allowing for the detection of long-term trends and cyclic variations. The following procedures were applied:  Calculation of multi-year mean values and standard deviations;  Determination of minimum and maximum precipitation levels;  Computation of the coefficient of variation (Cv) to evaluate interannual irregularity;  Trend analysis using moving averages and regression equations to assess the direction and rate of climatic change;  Construction of dynamic, seasonal, and interannual graphs to visualize long-term variability. Additionally, seasonal totals were calculated for winter (December–February), spring (March–May), summer (June–August), and autumn (September–November), allowing the determination of each season’s contribution to the annual water balance. To ensure accuracy, data consistency was verified by cross-checking with adjacent meteorological stations (Zomin and Gallaorol). The statistical analysis was performed using Microsoft Excel 2021 and IBM SPSS Statistics 25.0. The level of statistical significance for differences and trend slopes was set at p < 0.05. Results and Discussion 1. General Characteristics of Moisture The average annual precipitation for the 25-year period amounted to 530.9 mm, indicating moderately humid climatic conditions. The maximum annual total was recorded in 2002 (626.7 mm), while the minimum occurred in 2015 (370.8 mm). The amplitude of variation (Δ = 256 mm) demonstrates high interannual variability, typical for the foothill climatic zones of Central Asia. Seasonal analysis revealed that 70–75% of total annual precipitation occurs during the winter– SCIENCE AND INNOVATION INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 4 ISSUE 10 OCTOBER 2025 ISSN: 2181-3337 | SCIENTISTS.UZ 43 spring period, confirming the dominance of Mediterranean cyclonic activity and western air mass advection.  Winter (December–February): 350–380 mm (≈30–35% of annual total).  Spring (March–May): 400–450 mm (≈35–40%), marking the key phase of soil moisture accumulation.  Summer (June–August): only 80–120 mm (≈10%), reflecting strong aridity.  Autumn (September–November): 200–250 mm (≈15%), signaling a gradual transition to the humid season. This pronounced seasonal asymmetry defines the continental climate type of the Sangzar– Bakhmal region and indicates that soil moisture and vegetation development depend critically on the timing and amount of winter–spring precipitation. The findings underscore the necessity for water retention and irrigation systems to mitigate summer dryness. 2. Interannual Dynamics The analysis of the 25-year time series revealed three main climatic phases in the evolution of precipitation patterns: 1. 2000–2009 — Moderately humid phase. Average precipitation: 465–480 mm/year. Characterized by relative climatic stability, with balanced seasonal moisture and minor deviations from the multi-year mean. 2. 2010–2016 — Aridization phase. Average precipitation: 370–420 mm/year. This period coincided with a prolonged weakening of westerly atmospheric circulation and the strengthening of continental anticyclonic influence. The reduction in winter and spring rainfall led to soil moisture deficits, reduced crop yields, and accelerated pasture degradation. 3. 2017–2024 — Re-humidification phase. Average precipitation: >500 mm/year. The observed recovery indicates a shift in regional atmospheric circulation, possibly due to the increasing influence of Mediterranean cyclones and rising sea surface temperatures in the Indian Ocean, which enhanced moisture advection into Central Asia. The trend analysis demonstrates a positive slope (R² = 0.63), confirming a gradual recovery of humidity after 2017. This pattern is consistent with global climate models predicting greater interannual variability rather than linear aridization. 3. Seasonal Features Seasonal fluctuations show that March–April and November–December contribute the largest shares to the total annual precipitation — up to 130–136 mm and 120–125 mm respectively. These peaks are linked to the activity of Mediterranean and Black Sea cyclones. The summer months remain distinctly arid, although exceptions such as July 2020 (91.8 mm) indicate occasional convective rainfall anomalies, typically associated with local mesoscale systems. Such events, while episodic, significantly influence short-term water balance and may trigger flash floods or soil erosion in mountainous catchments. The coexistence of drought years (e.g., 2015) and wet years (e.g., 2002, 2021) underscores the region’s climatic instability and supports the hypothesis of an ongoing increase in precipitation variability across Central Asia. 4. Statistical Parameters Indicator Value Average annual precipitation 530.9 mm Minimum (2015) 370.8 mm SCIENCE AND INNOVATION INTERNATIONAL SCIENTIFIC JOURNAL VOLUME 4 ISSUE 10 OCTOBER 2025 ISSN: 2181-3337 | SCIENTISTS.UZ 44 Maximum (2002) 626.7 mm Mean amplitude 256 mm Coefficient of variation (Cv) 25–30% Share of spring–winter precipitation ≈70% The coefficient of variation indicates a moderate-to-high variability level, suggesting the instability of precipitation patterns and high sensitivity of agroecosystems to climatic stressors. This variability emphasizes the need for adaptive agricultural planning, including the selection of drought-resistant crops and efficient irrigation scheduling. Conclusion The Sangzar–Bakhmal region demonstrates a distinctly seasonal precipitation regime and significant interannual variability, characteristic of the foothill zones of Central Asia. Most precipitation is concentrated in winter and spring, forming the main source of soil and groundwater recharge, while summer droughts continue to limit agricultural productivity. Over the 25-year observation period, three climatic phases were identified — moderate humidity (2000–2009), aridization (2010–2016), and partial recovery (2017–2024). These fluctuations reflect the cyclic nature of the regional climate system, driven by the complex interaction of continental and maritime air masses. To enhance the resilience of agro-ecosystems and ensure sustainable water management, it is recommended to:  Implement water-saving and drip irrigation technologies;  Develop reservoirs and runoff accumulation systems to regulate seasonal water availability;  Strengthen regional climate monitoring using GIS-based and remote sensing tools;  Incorporate long-term precipitation forecasting into agro-climatic planning and land-use strategies. The findings of this study can serve as a scientific basis for regional climate adaptation programs, as well as for predictive hydrological modeling, soil protection, and agro-ecological zoning in the context of Uzbekistan’s climate change resilience policies. REFERENCES 1. Niyazmetov U.Kh., Tozhiev Z.T. Tog‘oldi lalmiy yerlarini degradatsiyadan himoya qilish [Protection of Foothill Rainfed Lands from Degradation]. – Tashkent, 2025. – С. 5–35. 2. Voitov A.B. va boshq. 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