Remote sensing-based monitoring of coverage and depth of snow in northern Xinjiang

The snow disaster often takes place in the north of Xinjiang.So it is of great significance to exactly monitor the snow distribution and snow depth in the northern Xinjiang,which can provide scientific basis for snow disaster prevention and reduction.In recent years,NDSI is mainly used to abstract the snow cover with MODIS data.The NDSI is a spectral ratio that takes advantage of the spectral difference of snow in short-wave infrared and visible spectral bands.It can only discern one pixel into snow or other features,and can not satisfy accurate drainage basin snow cover mapping and snow parameter extracting.In this study,linear spectrum mixing model was used to abstract snow fraction in the north of Xinjiang.Then we established the relationship between snow fraction and NDSI and evaluated whether NDSI can be used to estimate the cover rate of snow within a 250m pixel.The result showed that they had good linear relationship.The mean absolute error for 25 true measured points was 0.06.Moreover,we analyzed the correlation between snow depth and the reflected spectrum of snow and compared the true measured snow reflected spectrum with the image reflected spectrum.The most sensitive bands to snow depth were chosen.At last,the snow depth-inversing model was built.