Hydrological Modelling of Runoff and Sediment Yield Dynamics Upstream of Eleyele Lake, Oyo State, Nigeria

Water is a critical natural resource, comprising approximately 60% of human body weight and playing a vital role in all physiological processes. However, water quality has deteriorated in recent years due to the presence of harmful contaminants, posing potential health risks. Hence, the objective of this paper is to assess the modelling runoff and sediment yield dynamics of the Upstream of Eleyele Lake Watershed, Oyo State, Nigeria using Geographic Information Systems (GIS) alongside the Soil and Water Assessment Tool (SWAT). The model's predictions indicated an annual surface runoff of 122.56 m³/s and a sediment yield of 26.02 t/ha within the study area. These levels suggest a significant risk of flooding and heightened susceptibility to soil erosion. Consequently, it is recommended that further modeling efforts be employed to identify erosion-prone zones with greater precision across the watershed, enabling the development of effective management strategies to mitigate these risks.