Abstract:

VIC model is a distributed hydrological model based on grid,which is flexible to be coupled with GCMs to evaluate the effect of climate change on hydrological process. As the first part of this study,VIC model for the Xitiaoxi catchment with a spatial resolution of 5 km×5 km for each grid was developed.According to the flow routing characteristics in the Xitiaoxi catchment,a routing scheme developed by Dag Lohman with the unit hydrograph method for overland flow and the linear SaintVenant method for channel flow was used to route the simulated daily runoff to the outlet of Xitiaoxi catchment to do model calibration and validation based on observed data (1990~2000) from Hengtangcun gauging station.The results show that VIC model was adaptable for the study area,and the relative errors of the annual average runoff in Hengtangcun hydrologic station were 0.77% and 3.43% respectively.The coefficient of determination and NashSuttcliffe efficiency coefficient were both greater than 0.75.Especially for the simulation of discharge during flood seasons, deterministic coefficient were all greater than 0.80. It is feasible to use VIC model to analyze the response of flood on future climate change,and the related results will be presented in the following partner paper.〖