Application of HEC-HMS for the Assessment of Water Availability in Fincha and Didessa Sub-basin, Ethiopia

Abstract

The water resources availability assessment required for determination of optimal allocation and planning of water resources. This study is mainly focus on the water resources availability in the Fincha and Didessa sub-basin of Ethiopia by using HEC-HMS. The performance of the model was assessed via calibration at gauging station using Relative Volume Error (D), coefficient of determination (R²) and Nash-Sutcliffe Efficiency (NSE) performance coefficients. Then the model was validated using the parameters optimized during model calibration. The availability of water resources assessed at different watershed created to see at local level and finally at outlet point to Main River for each sub-basin separately. The HEC-HMS model shows a good performance Little anger which resulted D=2.58, R²=0.75 and NSE=0.63 during calibration and D=4.32, R²=0.77 and NSE=0.46 during validation and Neshi D=-1.37, R²=0.53 and NSE=0.58 during calibration and D=6.98, R²=0.68 and NSE=0.58 during validation for Didessa and Fincha Sub basin respectively. The parameters optimized at little Anger and Neshi gauging station was used for flow simulation to assess water resources availability on monthly and annual basis. The flow components were also separated at small catchment considered for all sub-basin. The result shows that high percentage of flow occupied by Direct Runoff for both Didessa and Fincha sub basins. So the available water in the sub-basins should be allocated fairly and accurately for water resources projects for effective utilization of the country water resources.

Keywords: Fincha and Didessa sub-basin, HEC-HMS, Water Resources Availability.

DOI: 10.7176/JEES/10-11-05

Publication date: November 30^th 2020