Evaluation of the Accuracy of TRMM Satellite for Estimating Precipitation andRunoff Values in Shapour River Basin in Fars Province

The Rainfall and runoff models are one of the methods for estimating runoff and are suitable tools for studying hydrological processes and assessing water resources. This study amid toevaluate the accuracy of precipitation and run-off estimation from the TRMM Satellite and it’s modified in Shapour river basin in Fars province. For this purpose, the hourly, daily and monthly rainfall data of stations which located in the Shapour basin during 2011-2016 were used. In continue, the calibrated HEC-HMS model was used to assess using precipitation gauge data and satellite TRMM imagery as input in this model to estimate run-off. According to the results of the modified TRMM and corrected TRMM models have less accurate precision in the hourly and daily scales as compared to monthly scale. The results of rainfall estimation from the modified TRMM model in the monthly time scales have the explanation coefficient (R2) more than 0.86 at the studied stations. The results of rainfall-runoff simulation of the calibrated model also showed that the best result of the estimated runoff from the station's rainfall data was obtained, with an RMSE equal to 11.94 m3/s.