Modelling Surface Water Potential of Somodo Watershed Using SWAT Model

Abstract

Despite increased worldwide water demand, freshwater availability is decreasing as a result of population expansion, industrialization, land use, and climate change. As a result, in order to provide strategic information for long-term water security planning, it is required to quantify the water resources potential. The objective of this study was to determine the surface water potential of the Somodo watershed. GPS, GIS, Arc SWAT, and SWAT-CUP software were all utilized to collect data. Secondary data, such as DEM, land use/land cover maps, soil maps, stream flow, and meteorological data, were collected from appropriate institutions. We investigated the model's sensitivity, calibration, and validation. According to the findings, surface runoff and base flow were the most sensitive parameters of stream flow in the Somodo watershed. The statistical results for model performance revealed a very good agreement (R² of 0.795 and NSE of 0.68) between the simulated and observed flow for calibration, and a very good agreement (R² of 0.821 and NSE of 0.7) between the observed and simulated stream flow for validation. The catchment, with a total watershed area of 19860 hectares, generated 56.75 million cubic meter (MCM) surface runoff per year, according to the model. The watershed's surface water potential of 56.75 MCM is sufficient to meet a variety of water demands.