Performance Comparison of Conceptual Rainfall-Runoff Models on Muger Catchment (Abbay River Basin)
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Date
2011-01
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Addis Ababa University
Abstract
The research is aimed at conducting catchment modeling for better understanding of hydrologic functioning and runoff generation mechanisms of the Muger catchment and selecting the best conceptual rainfall-runoff model that can be used in the design, planning, and management of water resources in Muger sub catchment (Abbay River basin. The conceptual rainfall runoff models chosen for this study are SMAR and HBV-light (Beta Version). Each of the models was applied to test the catchment, using split record evaluation, involving the calibration and verification periods (about 60% for calibration and 40% for verification). During calibration period of each model, the optimized parameters which give good performance result were determined (Reff=0.7) for both models. These optimized parameters are validated. Performance of the model in the validation period indicates that the efficiency is better than calibration period for both models. For the models SMAR and HBV the obtained Reff during validation is 0.70 and 0.71 respectively. Qualitative analysis of models shows that both models have poor performance in producing extreme flows such as floods and low flows. Model parameter transferability test was conducted on the daily time step models showed less performance in Aleltu catchment; whereas the monthly time step model showed high Reff values for both models. The discrepancy occurred between simulated and observed runoff may be due to in adequacy of model structure, human intervention, incorrect estimation of parameters especially in case of manual optimization , if there is an interflow between catchments, the quality of data and the absence of any substantial, consistent , or coherent relationship in the data used to calibrate the models. Key words: Muger; HBV; SMAR; Rainfall-Runoff
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Keywords
Muger; HBV; SMAR; Rainfall-Runoff