An improved method for mapping debris-covered glaciers with satellite multispectral image data and digital elevation model

Automated glacier mapping from satellite multispectral image data is very difficult because of the similar spectral characters of lateral and terminal moraine with that of neighbor rock. Paul (2002) has developed a method which integrates an ASTER multispectral image with a digital elevation model to map two debris-covered glaciers in the Alps. However, there are some problems when using the method in many mountain glaciers in the West of China. The critical slopes which identify the debris-covered tongue from rocks were tested first, which reveals that there is not a unique critical slope for all glaciers. Vectors from the China Glacier Inventory were used to derive expansion and shrinkage acting as a mask. A Temperature Index image was calculated by the one window algorithm from Landsat band 6 and NDVI. The method combines the advantage of Paul´s method with the mask and Temperature Index. Most of the processing can be done automatically. It was applied to Keqikaer debris-covered glacier, west Tianshan Mountain, China.