Catchment characterization for water resource monitoring and management, Upper Awash Basin, Ethiopia

This study implements Digital Elevation Model (DEM) of Ethiopia to delineate the catchment, to develop the topographic map and slope map of the study area. Enhanced Thematic Mapper Plus (ETM+) satellite imagery was used to develop land use classification of the catchment; also the soil map of the study area was prepared from data-base of the Northeastern African countries. Finally the hydrologic characteristic of the catchment such as annual groundwater recharge, surface runoff and evapotranspiration was estimated through a grid-based physically distributed model, WetSpass. This method was tested in a 2,20200ha catchment with dominant agricultural lands where Settlement is actively increasing. The land cover classification has an overall accuracy of 96.8%. Agriculture 49.3%, grassland 16.5%, Tree & Shrub 15%, Water body 7% and Settlement 11% are the most dominant land cover within the catchment. The catchment is covered with four different soil textural classes, 54% of silty clay, 34% of silty loam, 8% of clay and 4% of loam soil. The hydrologic characteristic of the catchment in this study demonstrates spatial annual rainfall distribution as surface runoff (17.6%), evapotranspiration (73.5%), and groundwater recharge of (8.9%). The catchment characterization result in this study can be utilized by scientific community, policymakers, donors, non-governmental organizations, and other development practitioners to deliver the right policy and programs for water resource monitoring and management in the study area