Influence of Urbanisation on Landforms/Landscape Changes in Benin City, Edo State, Nigeria

 Corresponding author: Bisco PG Copyright © 2025 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. Influence of Urbanisation on Landforms/Landscape Changes in Benin City, Edo State, Nigeria Bisco P G *, Obafemi A. A. and Ogoro M Department of Geography and Environmental Management, University of Port Harcourt, Port Harcourt, Nigeria. World Journal of Advanced Research and Reviews, 2025, 27(03), 1692-1706 Publication history: Received on 19 August 2025; revised on 25 September 2025; accepted on 27 September 2025 Article DOI: https://doi.org/10.30574/wjarr.2025.27.3.3330 Abstract The study examined the influence of urbanization on landforms/landscape Changes in Benin City, Edo State, Nigeria. The study made use of Landsat imagery of 1990, 2000, 2010 and 2020 to determine the rate of urbanization and digital elevation model of 2000 and 2020 to discover the geomorphological changes over time in the study area. Descriptive statistics were used for data analysis. Findings reveal that built up area increased from 194.24 km2 in 1990 to 407.19 km2 in 2020 of the total study area suggesting 109.62% increase in the spatial extent of the built area, The landforms evolution between 2000 and 2020 in Benin City observed that the valley covered a spatial extent of 487.16 sq km (19.21%), flat surfaces/middle slope covered 703.42 sq km (27.74%), upper slope covered 1016.66 sq km (40.09%) and peak/hill covered 328.49 sq km (12.95%). In the year 2020, the landform evolution revealed valley covering 384.62 sq km (15.10%), flat surfaces/middle slopes covering 1366.9 sq km (53.66%) and peak/hill covered 795.62 sq km (31.24%). The study concluded that the landuse and land cover change over time has affected the evolution of landforms pattern in Benin City; and in most areas, erosion has deeply taken place which has reduced the heights of some parts of the topography. It is recommended that the urban growth or sprawl evidently demonstrated in Benin City should be controlled under the supervision of the Town Planning Offices at the State level and Local Government Areas levels to ensure that the environment is prevented against unwanted environmental hazards. Keywords: Urbanisation; Landforms; Landuse; Evolution; Elevation; Hazard 1. Introduction Urbanization is one of the major challenges that the world faces today. At least 0.5% of the terrestrial area is now urbanized (Schneider et al. 2009). In 2015, 54% of the world population was living in urban areas and in some countries this percentage is close to 100%. Humans have been using land and its resources for centuries in a pursuit of their better lives. The way humans have used land and exploited its resources over time is a serious problem (Cieslewicz, 2002; Ochola, 2024) as it has altered land cover and impacted the functioning of the ecosystem. With the advent of agriculture, modern technology, and the rise of capitalist mode of economy, the exploitation of land and its resources has increased dramatically. More seriously, at least 0.5% of the terrestrial area is now urbanized (Schneider et al. 2009). In 2015, 54% of the world population was living in urban areas and in some countries this percentage is close to 100%). In several parts of the world annual urbanization rates exceed 5% (e.g. Oman 8.54%; Rwanda 6.43%; Burkina Faso 5.87%; Uganda 5.43%; Burundi 5.66%; Tanzania 5.36%; Niger 5.14%; Data: CIA), which means that urban sprawl is a widespread phenomenon. Urbanization and correlated infrastructure building highly impact and sometimes completely destroy landforms. Human activities have a substantial and cumulative effect on the landscape and its landforms. World Journal of Advanced Research and Reviews, 2025, 27(03), 1692-1706 1693 Geomorphologic changes result from a range of anthropogenic activities including forest clearing, agriculture, land draining and filling, mining and quarrying, channelization, irrigation, and construction of dams or other engineering features (Nir, 1983). These activities involve the intentional removal and deposition of material as well as the unintentional effects of hydrological changes and resulting erosion and sedimentation (Hooke, 2000). Anthropogenic landforms are created at a variety of spatial scales. Local scale landforms result from excavation, cutting, and grading to modify slopes and drainage patterns to create level ground for development and transportation infrastructure (Nir, 1983). Broader scale landforms are created by mining and quarrying, as well as subsidence due to water or mineral resource extraction. Depositional landforms, or ‘man-made ground’ typically entail the use of fill material, as well as waste dumps, and may occur at a range of scales (Douglas et al., 2010). The cumulative geomorphologic effects of anthropogenic activity are most pronounced in areas of dense human occupation (e.g. in urban spaces) and primarily occur in the early-urban to the mid-urban stages of development (Nir, 1983). Anthropogenic activities result in processes that considerably change the landscape (Machar, 2012) and even surpass the activeness of natural exogenic processes (Hooke & Martín-Duque 2012; Nir & Man 1985). These activities often have great importance from the economic point of view (quarrying, mining fossil fuels, urban development, adjusting landscape for agriculture, construction of large dams which provide water reserves for industries and cities etc.), but from the conservation point of view, they lead to degradation of the landscape (Goudie 2006) and protected areas (Oprsal et al., 2018). In some cases the landscape is completely remodeled and there is no evidence of past landforms (Szabó et al., 2010; Kilianova, et al., 2017). An anthropogenic landform is created by human activity, particularly by construction, excavation, hydrological interference and farming (Kilianova et al, 2017). Anthropogenic landforms can be classified by the character of their impact: direct or indirect (Li et al., 2017), and respectively intentional or unintentional (primary anthropogenic landforms and secondary anthropogenic landforms). A few of the previous studies reported the impact of urbanization on landform changes over time and as a result the present study is focusing at examining the influence of urbanisation on landforms/landscape changes in Benin City, Edo State, Nigeria. 2. Materials and Methods The study was carried out in Benin City, Edo State, Nigeria (Figure 1). Benin is the state capital of Edo State; it is located in the Southern part of Nigeria. Situated approximately 40 kilometers North of the Benin Rivers and 320 Kilometers by road east of lagos. Benin City is one of the oldest cities in Nigeria. The population of Benin at as 2006 is 1,147,188 and a land mass of 56,807 hectares (NPC 2006). The metropolis of the city cuts across four local government areas, Egor, Oredo, Ovia North-East and Ikpoba-Okha. The city has remained a major commercial has linking the western, eastern, northern, and southern part of Nigeria. Agricultural production is a major occupation of the people. The city lies within the tropical rainforest belt of Nigeria and it is a home to several forest production including timber, oil notion and rubber. The people of Benin City are known as Edo or Bini. They have one of the richest dress cultures on the African continent and are known for their beads, body marks, bangles, anklets and raffia work. Benin City is a home of Nigeria’s institutions of higher learning. These educational institutions, industrial activities coupled with socio-economic encourage the movement of population growth. The sources of data for this study were both primary and secondary data sources. The primary data included the recording of the coordinates of some of the landmarks that can guide in the classification of the landuse/land cover and other geomorphic features present in each of the study locations. This was achieved by using the global positioning system (GPS). The secondary data included multi-temporal landsat satellite datasets of 1990, 2000, 2010 and 2020. The 1990 landsat imagery was obtained from Landsat 4 or 5 Thematic Mapper (TM), while that of 2000 and 2010 were obtained from Landsat 7 Enhanced Thematic Mapper-plus and 2020 was Landsat 8 Operational Land Imager/Thermal Infrared Sensor (OLI/TIRS). All these imageries have 30 m resolution using nonlinear classification and artificial visual interpretation methods. The Digital Elevation Map of Shuttle Radar Topographic Mission (STRM) of 1 Arc-Second Global resolution from the website of Earth Resources Observation and Science (EROS) Center. This was collected for the years 2000 and 2020 to examine the variation in the topography of the study area. The STRM of 2000 and 2020 were used because they were the available DEM that are from reliable sources while those of 1990 and 2010 were not available. The urban growth pattern of the study locations was determined using the landsat imageries of 1990, 2000, 2010 and 2020. The elevation, slope rise percent, slope degree, relief contours drainage network and landforms were obtained from the DEM imagery of 2000 and 2020. The landsat imageries of the study locations were classified into different major landuse/land cover using the maximum likelihood supervised classification method in the ArcGIS environment. World Journal of Advanced Research and Reviews, 2025, 27(03), 1692-1706 1694 Source: Edo State Ministry of Land and Surveying, 2024 Figure 1 Benin City Metropolis The workflow chart for the evolution of landscape change patterns in this study was obtained by using topographical position index (TPI). The Topographic Position Index (TPI) is a geospatial analysis tool used to classify terrain by comparing the elevation of a cell to the average elevation of its surrounding cells within a defined radius (De Reu et al., 2013). This comparison helps in identifying landforms and slope positions, such as ridges, valleys, and slopes. Essentially, TPI highlights whether a cell is higher or lower than its neighbours. Topographic Position Index (TPI) is a topographic position classification identifying upper, middle and lower parts of the landscape. “TPI measures the difference between elevation at the central point (z0) and the average elevation (ẑ) around it within a predetermined radius (R), where (n) the total number of surrounding points employed in the evaluation”[Wilson and Gallant, 2000; Jenness, 2006; Al-Sababhah, 2023]: Ẑ = 1/𝑛R 1 nR ∑i ∈ R Zi …………………………………………………. Equ 1. World Journal of Advanced Research and Reviews, 2025, 27(03), 1692-1706 1695 The output of the TPI value is positive when the central point is situated higher than its neighborhood and negative when it is situated lower. The output values mostly range between +1 and −1, and values outside this range may indicate anomalies within the DEM. Moreover, “DEV measures the topographic position of the central point (z0) using TPI, and the standard deviation of the elevation (SD)” [22]. This can be represented as follows: DEV = z0−Ẑ/SD …………………………………………………………………… Equ. 2 TPI is computed with the focal function by Arc GIS tools, as follows: TPI < − focal(x, w = f, fun = function(x, . . . ) x[5] −mean(x[−5]))……………….. Equ 3 Where positive TPI values point to high areas as ridges, negative values represent lower areas as valleys, and zero value indicates flat areas (Wilson, 2000) Figure 2(a) Landform types according to TPI values, (b) Positive and negative TPI values Descriptive statistics were employed for the data analysis. Figure 3 Elevation values change according to TPI, at three scales: a TPI is zero, b TPI higher than zero, c TPI lower than zero (Wilson, 2000; Al-Sababhah, 2023) World Journal of Advanced Research and Reviews, 2025, 27(03), 1692-1706 1696 3. Results and Discussions 3.1. Landuse and Land cover Analysis of Benin City from 1990 to 2020 Table 1 shows the landuse/land cover pattern in Benin City of Edo State between 1990 and 2020. In 1990, it is revealed that waterbodies covered 426.58km2 (16.56%) of total study area, thick vegetation had 1547.75 km2 (60.09%), farmlands had 407.01 km2 (15.80%), and built up area had 194.24 km2 (7.54%) (Figure 4). In 2000, it is shown that waterbodies covered 411.58km2 (15.98%) of total study area, thick vegetation had 1510.11 km2 (58.63%), farmlands had 338.21 km2 (13.13%), and built up area had 315.69 km2 (12.26%) (Figure 5). In 2010, it is shown that waterbodies covered 358.87km2 (13.93%) of total study area, thick vegetation had 1418.25 km2 (55.07%), farmlands had 428.2 km2 (16.43%), and built up area had 375.27 km2 (14.27%) (Figure 6). In 2010, it is shown that waterbodies covered 397.45km2 (15.43%) of total study area, thick vegetation had 1358.66 km2 (52.75%), farmlands had 412.29 km2 (16.01%), and built up area had 407.19 km2 (15.81%) (Figure 7). Figure 4 Landuse/Land cover of Benin City in 1990 World Journal of Advanced Research and Reviews, 2025, 27(03), 1692-1706 1697 Figure 5 Landuse/Land cover of Benin City in 2010 World Journal of Advanced Research and Reviews, 2025, 27(03), 1692-1706 1698 Figure 6 Landuse/Land cover of Benin City in 2010 World Journal of Advanced Research and Reviews, 2025, 27(03), 1692-1706 1699 Figure 7 Landuse/Land cover of Benin City in 2020 Table 1 Landuse change from 1990 to 2020 in Benin and Environs Landuse 1990 2000 2010 2020 Areal coverage (km2) Percentage (%) Areal coverage (km2) Percentage (%) Areal coverage (km2) Percentage (%) Areal coverage (km2) Percentage (%) Waterbodies 426.58 16.56 411.58 15.98 358.87 13.93 397.45 15.43 Thick Vegetation 1547.75 60.09 1510.11 58.63 1418.25 55.07 1358.66 52.75 Farmlands 407.01 15.80 338.21 13.13 423.2 16.43 412.29 16.01 Built Up Area 194.25 7.54 315.69 12.26 375.27 14.57 407.19 15.81 Total 2575.59 100.00 2575.59 100.00 2575.59 100.00 2575.59 100.00 World Journal of Advanced Research and Reviews, 2025, 27(03), 1692-1706 1700 The landuse change and percentage change of Benin City is presented in Table 2. From 1990 to 2000, the analysis showed that thick vegetation reduced by 37.64 km2 (23.61%), and waterbodies reduced by 15.0 km2 (3.52%) while the spatial extent of farmlands increased by 68.80 sq km (16.90%), and built up area increased by 121.44 sq km (62.52%). From 2000 to 2010, the analysis showed that thick vegetation reduced by 91.86 km2 (6.08%), and waterbodies reduced by 52.71 km2 (12.81%) while the spatial extent of farmlands increased by 84.99 sq km (25.13%), and built up area increased by 59.58 sq km (18.87%). From 2010 to 2020, the analysis showed that thick vegetation reduced by 59.59 km2 (4.20%), and farmlands reduced by 10.91 km2 (2.58%) while the spatial extent of waterbodies increased by 38.58 sq km (10.75%), and built up area increased by 31.92 sq km (8.51%). In a nutshell, from 1990 to 2020 , it was discovered that thick vegetation reduced by 189.09 km2 (12.22%) and waterbodies reduced by 29.13 km2 (6.83%) while the spatial extent of farmlands increased by 5.28 sq km (1.30%), and built up area increased by 212.94 sq km (109.62%). Table 2 Landuse change and percentage change between 1990 and 2020 in Benin City and Environs Landuse 1990 2000 Rate of Change Percentage of Change (%) Waterbodies 426.58 411.58 -15 -3.52 Thick Vegetation 1547.75 1510.11 -37.64 -2.43 Farmlands 407.01 338.21 -68.8 -16.90 Built Up Area 194.25 315.69 121.44 62.52 Total 2575.59 2575.59 Landuse 2000 2010 Waterbodies 411.58 358.87 -52.71 -12.81 Thick Vegetation 1510.11 1418.25 -91.86 -6.08 Farmlands 338.21 423.2 84.99 25.13 Built Up Area 315.69 375.27 59.58 18.87 Total 2575.59 2575.59 Landuse 2010 2020 Waterbodies 358.87 397.45 38.58 10.75 Thick Vegetation 1418.25 1358.66 -59.59 -4.20 Farmlands 423.2 412.29 -10.91 -2.58 Built Up Area 375.27 407.19 31.92 8.51 Total 2575.59 2575.59 Landuse 1990 2020 Waterbodies 426.58 397.45 -29.13 -6.83 Thick Vegetation 1547.75 1358.66 -189.09 -12.22 Farmlands 407.01 412.29 5.28 1.30 Built Up Area 194.25 407.19 212.94 109.62 Total 2575.59 2575.59