Comparison of SRM and WetSpa models efficiency for snowmelt runoff simulation

Abstract

Snow melting stems from a part of precipitation in mountainous regions, which confines hydrological and hydraulic activities. Therefore, its role in runoff formation should be evaluated independently. In this paper, the performance of WetSpa and SRM models in snowmelt-runoff simulation is assessed. Aiming at this goal, 2-year regional data of Horo-Dehno watershed (263 km2) located in Iran from September 2006 to September 2008 was chosen. snowmelt-runoff model (SRM) is a conceptual physical model designed to simulate and forecast daily stream flow in mountainous watersheds where snowmelt is the main runoff factor. SRM simulates snowmelt-runoff using meteorological data and satellite images of snow cover, which, in this research, the latter is MODIS radiometer images. On the other side, water and energy transfer between soil, plants and atmosphere (WetSpa) is a distributed spatial-physical model that simulates different hydrological processes including snow melting in a cellular manner at hourly and daily time steps by employing energy balance as well as degree-day approaches. In addition, the WetSpa model for simulating different processes requires meteorological data and spatial maps. In this study, the simulation results showed the Nash–Sutcliffe efficiency of 0.54 and 0.53 for the SRM, and, 0.77 and 0.8 for the WetSpa in calibration and validation periods, respectively. Hence, in the studied area, based on the results of the qualitative (visual comparison of hydrographs as output models) and quantitative (evaluation criteria) of snowmelt-runoff simulation, the WetSpa outperformed the SRM.