Assessment of Soil Erosion Potential in Lagelu Local Government Area, Oyo State Nigeria

Soil erosion is a critical environmental issue that affects soil fertility, agricultural productivity, and ecosystem stability, particularly in developing regions. This study assesses soil erosion susceptibility in Lagelu, Oyo State Southwestern Nigeria, using an integrated approach that combines topographic, climatic, and soil-related factors within a Geographic Information System (GIS) environment. The major factors considered include slope, rainfall, land use/land cover, soil texture, and soil organic matter. Slope gradient was derived from ASTER Digital Elevation Model (DEM), while land use/land cover classification was obtained from Landsat 8 imagery. Soil texture (sand, silt, and clay fractions) and organic matter content were analysed to evaluate soil resistance to erosion, and rainfall data were used to determine the precipitation. The Analytical Hierarchy Process (AHP) was employed to assign weights to these factors, and a weighted overlay analysis was conducted to produce an erosion hazard map. The results reveal that areas with steep slopes, high rainfall intensity, sparse vegetation cover, and high sand content are more vulnerable to erosion, whereas soils with higher clay, silt, and organic matter content exhibit greater stability. The erosion susceptibility map indicates that 19% of the area falls within low risk, 76% within moderate risk, and 5% within high-risk zones. The predominance of moderate-risk areas suggests widespread exposure to erosion processes across the region. The study highlights the combined influence of natural and anthropogenic factors on soil erosion and provides a scientific basis for implementing effective soil conservation measures, land use planning, and environmental management strategies in the study area.