SWAT-Based Modeling On Snowmelt-Runoff In Xilinhe Basin

Rivers on grassland play a typically important role in the grassland environment system. Especially in the cold-arid-regions, frozen soil, melt snow, and rainfall control the hydrological process of the basins. As the global climate change and development of local economics, water shortage is one of the main factors that have impacted on the social and eco-environment sustainable development. As a result of this, more and more attention has been paid on how to scientifically plan and utilize regional water resources regarding to the river basins on the grassland.Xilin River is a typical grassland river located in Inner Mongolia, which is a cold-arid-region in the north of China. Its basin was investigated and some necessary experiments were carried out by means of hydrological processes. The hydrological nonlinear system theory, geological statistics, remote sensing and geographic information system were used to determine the parameters that are required by SWAT. One of the characteristics that need to be specially deal with is to get better understanding about the snowmelt runoff processes in order to simulate the hydrological processes by SWAT. The ’seasonal snowmelt runoff was analyzed and trial and error method was applied to improve the application limits of SWAT. The results showed that R2is0.79, Ene is0.76in the calibration period, however in the verification period, R2is0.61and Ene is0.53. This implied that SWAT model could be used in the cold-arid-region regions if it is improved by considering the snowmelt runoff processes.In conclusion, using SWAT to simulate the hydrological processes in the cold-arid-regions with a characteristic of snowmelt-runoff could represent different accuracies. The best fitting result between the observed and simulated data was obtained for the normal hydrologic years, the worst for the dry years, between which the accuracies were partial wet years> wet years> partial dry year.