关键词: SRM融雪径流模型, 融雪径流, MODIS, IDW, 乌鲁木齐河源区

Abstract: There are seven glaciers and large-scale snow above the Zongkong hydrological station of Urumqi River，and the snowmelt runoff in Urumqi River contribute significantly in the glacier ice and snow melting period. It is therefore essential to simulate the snow-melt runoff of Urumqi River，and also meaningful for the utilization of the snow water resources in the whole basin or even in Xinjiang province. In this paper，the SRM was applied to simulate snowmelt runoff in the headwaters region of Urumqi River. It is currently based on a simple degree day method.The daily precipitation，air temperature and snow cover area are the input data. In addition to the input variables，a number of basin characteristics such as basin area，zone area and the area elevation curve are also needed. The Digital Elevation Model are used to divide different zones of the basin，and MOD10A2 data are used for the accumulation of snow. Besides，the meteorological and hydrology data observed from May to August in 2008 are also used for this model. The region is divided to three zones and we get the curves of snow coverage shrinking derived from the MOD10A2 snow products，and the recession coefficients are also calculated in detail. According to the simulation，a final simulation scheme is selected as the final decision．The simulation fit indexes of Nash-Sutcliffe coefficient（R²）is 0.702 and the volume difference（Dv）is 6.81% which are fitted to the accuracy of snow melt model，and it also indicates that the SRM model can be applied in the whole Urumqi River. In addition，this application suggests that Urumqi River will be necessary for snow-melt runoff to meet with the needs of irrigation supply and water supply. This is particularly important for utilization of Urumqi River water resources. Meanwhile，the research also shows that ：（1）This study concludes that the snowmelt runoff model based on a degree day factor can efficiently simulate the daily discharge in the snow and glacier-fed catchments of the headwaters region of Urumqi River. Parameters which are sensitive to the results are degree day factor，recession coefficient K，the critical temperature value．（2）Air temperature and precipitation as the direct drive variables are more sensitive to the model. As the temperature and precipitation are not strictly comply with the temperature and precipitation gradient in headwaters region of Urumqi River，the IDW interpolation was used to solve this problem，thus，it provides a new train thought for the precision of the SRM model. （3）The degree day factor is not stable in different height belt while the degree day factor selection and adjustment is also very important to the simulation. While the snow density is closely related to the degree day factor，actual measurement snow density data are needed to measure in all the height belt. （4）SRM don’t take the infiltration，interception and evapotranspiration into account，so the simulation runoff is less than the measured runoff. Meantime，the study area in this paper is 28.9 km²；consider the resolution of MOD10A2 is 500 m×500 m，there is a certain error in the curves of snow coverage shrinking. There are some shortcomings in this research；we intend to do better in the future research.

Key words:  Snowmelt-Runoff Model, snowmelt runoff, MODIS, IDW, Headwaters region of Urumqi River