ASSESMENT OF SOIL EROSION AND SEDIMENTATION IN SOME RIVER AROUND OYO TOWN

Soil erosion and sedimentation are pressing environmental issues that significantly impact agricultural productivity, water quality, and the sustainability of ecosystems. This study evaluates the extent and implications of soil erosion and sedimentation in selected rivers around Oyo town, with a focus on understanding the contributing factors, assessing the impacts, and proposing sustainable management practices. The research is justified by the growing degradation of soil and water resources in the region, driven by both natural and anthropogenic factors, which pose a threat to sustainable land use, food security, and environmental health.The study employed a comprehensive methodology to achieve its objectives. Soil samples were collected using an auger at a depth of 2 m, with the top 1 m discarded to ensure representative sampling. The samples were sieved using standard mesh sizes (2 mm, 1 mm, 0.5 mm, 0.25 mm) to determine particle size distribution. Water samples from rivers were collected and analyzed for key physicochemical parameters, including pH, total dissolved solids (TDS), electrical conductivity (EC), and heavy metal concentrations such as aluminum (Al), cadmium (Cd), and lead (Pb). Statistical analyses were performed to evaluate spatial variations and relationships among the parameters, while the results were used to identify trends and assess the impact of sedimentation on water quality. The results revealed that soil erosion is prevalent in the study area, with clay-dominated soils showing higher vulnerability due to poor drainage and cohesion. Water analysis indicated pH values ranging from 5.85 to 7.89, reflecting slightly acidic to neutral conditions, which can influence the solubility and mobility of nutrients and contaminants. TDS and EC values demonstrated variability, indicating the influence of sedimentation and runoff from agricultural and urban activities. Heavy metals were detected at varying concentrations; cadmium and lead were present at low levels, while aluminum showed significant spatial variability, with a maximum concentration of 1.907 mg/L. These findings underscore the dual impact of natural erosion processes and anthropogenic activities, such as deforestation, improper land use, and poor agricultural practices, on soil and water quality in the region. The study concludes that soil erosion and sedimentation significantly contribute to the degradation of both land and water resources in Oyo town. Current erosion control measures are insufficient to address the scale of the problem. The findings emphasize the need for the adoption of sustainable land management practices, including contour farming, terracing, afforestation, and the installation of sediment traps along riverbanks. These measures, combined with public awareness campaigns and policy interventions, are essential for mitigating erosion, conserving soil, improving water quality, and promoting environmental sustainability in the region