Correlation Analysis on Snow-Climate Factors and Its Effects on Snowmelt Runoff in Manasi River Basin

In this paper,we analyzed the relations and characters of runoff,snow,temperature and precipitation in Manasi river basin. Based on the distribution of landform,vegetation and snow cover,we found the system of the classified zone for the study basin. By using the data of 8-day MOD10A2,one production of MODIS,daily snow cover data were computed by the way of interpolation. Meanwhile,based on the character of vertical terrain in Tianshan Mountain,we used the DEM to get daily temperature and precipitation datum of each zone. Qualitative and quantitative analysis was made within the zone temperature,precipitation and snow cover area. And we also made quantitative analysis between snow cover area in the whole basin and runoff. Hungriness and plain in low elevation appears continuous positive temperature on March 22. Spruce and forest zone does on April 11. Cold meadow in high mountain does on May 14. Ice-snow zone does on June 12. The annual distribution of precipitation is very inequality. It mainly falls in summer and accounts for 43.39% of the yearly whole precipitation amount. There is separately 28.14%,13.04% and 15.24% in spring,autumn and winter. There was high correlation between snow cover area and temperature in every zone of the basin. With the temperature gradually increasing from March to June,snow began to melt. Except the ice-snow zone,snow in the other three zones entirely melted in the period. At the same time,snow and temperature had a linear correlation in cold meadow and ice-snow zones. The scatter dot between snow area of the whole basin and runoff showed that they had a good exponential correlation. In different years,there was a disciplinary change between snow cover area and runoff in the study area.