Assessment of Water Balance Components by Using Wetspass Model: The Case of Dengego Sub-basin, Eastern Ethiopia

Abstract

The search for new water resources, as well as the development of water balance models that can be used to control and manage the resource, is at the heart of the search for new water resources in eastern Ethiopia, particularly in the Dengego sub-basin, and its socio-economic significance in terms of water demand for agriculture and domestic use. The water balance components of the Dengego sub-basin were investigated using the WetSpass hydrological model. The goal of this study is to assess the water balance components in the Dengego sub-basin. According to WetSpass, the mean annual evapotranspiration, surface runoff, and groundwater recharge were 494.2, 173.6, and 20.2 mm, respectively. Actual evapotranspiration and surface runoff accounted for 25.2 percent and 71.8 percent of precipitation, respectively and recharge made up 2.9 percent of precipitation. Annually 7.3 million m3 of water recharges into the groundwater table as recharge from the precipitation on the entire watershed.The contribution of this study could be used as baseline information for regional water resource experts, policy makers and researchers for further investigation. It can also be concluded that integrated WetSpass and GIS-based models are good indicators for estimating and understanding of water balance components in a given watershed to implement an integrated watershed management plan for sustainable utilization and sustainable development.