Comparison of Degree-Day and Radiation base of Snowmelt Runoff Model (SRM) for Estimating Runoff from Snow Melting

In mountainous and snowy watersheds, runoff generated by snow melting is an important factor in changes in flow regime and plays an important role in stream water Supply and water resources. However, in such watersheds, hydrological and meteorological required data for simulation, especially snow survey data are usually not available. Therefore, there are many problems for simulation and forecasting runoff generated by snow melting. In this study, were used the degree-day and radiation base of SRM to estimate the runoff in the Beheshtabad watershed. The aim of this study was to evaluate the degree-day and radiation version of the model for estimating runoff from snow melting. Therefore, prepared the variables of classical and radiation SRM and snow cover was obtained from MODIS satellite images and then models were run for calibration period (2012-13) and validation period (2013-14). The efficiency factor (R2) in the validation period for SRM radiation model (0.71) is 13% more than the classic model (0.58) and the difference between total runoff volumes in the radiation SRM improved 7% compared to the classical model.