SIMULATING EROSION AND SEDIMENTATION RATE IN GOLINGA DAM CATCHMENT USING SWATPLUS MODEL, GHANA

Abstract

Soil erosion and sedimentation pose significant challenges to water resource management, particularly in dam catchments. Assessing the sediment yield and erosion rate on dam catchment is vital for sustaining the environment. This research employed the use Soil and Water Assessment Tool Plus (SWAT+) model to simulate sediment yield and erosion rates in the Golinga Dam catchment, Northern Ghana. The study rigorously adapted the following methodology: simulation, sensitivity analysis and calibration and validation, attaining NSE of 0.85, R2 of 0.85 and a PBIAS of 7.29% during calibration with a validation result depicting NSE of 0.81, R2 of 0.84 and a PBIAS of 8.11%. Using topographic, land use, soil properties and hydro-climatic data information, the model was used to accurately simulate erosion and sediment yield in the catchment, identified erosion prone areas with intensive agriculture or minimal vegetation cover and predicted best management practices which significantly reduced erosion and sedimentation. Results indicated a range of 1.3 to 2.7 tons/ha/yr of sedimentation in the landscape unit resulting in sediment yield of 49.8 to 52 ton/ha/yr in the dam. 6 scenarios of best management practices (BMP) were implemented to find an efficient soil and water conservation practice which would drastically reduce sediment yield, slow down erosion rate, and improve water quality. Out of the 6, a combined management practice (ie; grassed water way and filter strips) was the most effective (about 90% efficiency). This study emphasizes the importance of proactive management strategies in water resource planning and agriculture. It highlights the urgent need for responsive policies to strengthen resilience against anthropogenic activities that trigger sediment environmental degradation. Such measures are essential for ensuring the sustainable management of the Golinga Dam catchment, promoting long-term environmental stability and water security.