The Extraction of Snow Cover Information Based on MODIS Data and Spatial Modeler Tool

The snow cover, which is an important component of the climatic system and a main indicator factor of the global change, will affect temperature, precipitation and other climatic factors. Remote sensing technologies introduce a potential scientific basis for the extraction of snow cover information which is the basis and key of snow cover study. In this paper, the snow distribution information of Jilin Province, China was extracted based on the winter EOS-MODIS data of the year 2007. In the course of studying, according to typical spectral reflectance characteristics of snow, Normalized difference snow index (NDSI) and threshold segmentation method were introduced to extract the snow distribution information. It is found that different threshold values should be set according to elevation and different land cover types. To reduce the influence of vegetation density, Normalized difference vegetation index (NDVI) was also utilized. Finally, the snow cover information extraction model was established by spatial modeler tool in ERDAS software. The extraction result and accuracy validation indicate, (1)NDSI is necessary and significant on snow cover information extraction; (2) The combination of MODIS data and spatial modeling method is economical and efficient to extract the information of snow cover.