COMPARISON OF SATELLITE BASED RAINFALL TO GROUND STATION IN HYDROLOGICAL MODELLING, NESHI WATERSHED, ABBAY RIVER BASIN, ETHIOPIA

Abstract

For rainfall-runoff modeling, precise rainfall measurements are required to examine the geographical and temporal patterns of rainfall at various scales. In many impoverished nations, such as Ethiopia, accurate and reliable rainfall monitoring is scarce. The Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record (PRESIANN_CDR) satellite rainfall products for stream flow simulation are evaluated in this study at daily temporal and 0.05°×0.05° and 0.04°×0.04° spatial resolutions, respectively and simulated by HEC-HMS model. The Soil Conservation Service_Curve number, SCS_Unit Hydrograph, and Muskingum methods were utilized for loss, transformation, and routing computations, respectively, at the stated period and one day time step. The model was calibrated over fifteen years and the daily rainfall readings were verified during five years. The performance of HEC-HMS model and satellite rainfall was assessed using a coefficient of determination (R2 ), Net-Sutcliffe Efficiency (NSE), Root Mean Square Error (RMSE), and Percent of BIAS. The model Calibration and Validation results were described here (R2 =0.81, NSE =0.84, RMSE = 0.5, PBIAS = +30.10) and (R 2=0.79, NSE = 0.82, RMSE = 0.4, PBIAS = +28.72) throughout the periods, respectively. Satellite rainfall products could be useful inputs for modeling in areas where field data is lacking for a variety of hydrological applications. The results revealed that the observed and simulated hydrographs were almost identical. The HEC-HMS model accurately predicted catchment runoff for both satellite rainfall products according to the findings. As a consequence, Neshi discharge was successfully simulated for the time period studied and the results suggested that the utilization of satellite rainfall data was appropriate or solve the problem of data scarcity and the model was adequate for hydrological simulations in the Neshi Watershed.