GIS-based Identification and Preparation of Suitable Climatological Data Sources for Simulation Using Semi-Distributed Hydrological Models

Regarding to various sources of climatological data, identification of suitable sources and investigation of their usage effects on hydrological simulation is an important issue. Moreover, given that hydrological models employ different methods for preparation of climatological data, e.g. spatial interpolation of point climatological data, evaluation of the effects of different methods on hydrological simulation’s result is an important issue. Accordingly, this paper deals with different data sources and spatial interpolation of precipitation that are investigated in hydrological simulation of Mahabad Chai River Basin using SWAT model. Different climatological sources, i.e. field measurements of meteorological stations of MOE and IRIMO as well as reanalyzed data of CFSR project, and different interpolation methods, i.e. nearest neighborhood (NN) and inverse distance method (IDW) were employed and compared for preparation of inputs of SWAT model using a developed computational module in Module Builder framework of ArcMap. Then parameters sensitivity analysis, estimation and model validation were performed based on a period of 36-years monthly streamflow record. Results showed using CFSR data leads to Nash-Sutcliffe (NS) value of 0.58 as compared to climatological stations’ data which leads to NS value of 0.38. Additionally, IDW method showed a better performance significantly than the NN method, so that their NS index values were 0.79 and 0.56, respectively.