Glacier mapping in high mountains using DEMs, Landsat and ASTER data

Glaciers are sensitive climate indicators and thus subject to monitoring of environmental and climate changes. Remote sensing techniques are often the only way to analyze glaciers in remote mountains and to monitor a large number of glaciers at the same time. Although several glacier mapping methods exist, often, results are still not good enough for in-depth conclusions. In particular, this is true for debris-covered glaciers. For the Bernina Group in the Swiss Alps and for the northern Tien Shan in Kazakhstan and Kyrgyzstan a glacier mapping was undertaken employing digital elevation models (DEMs). DEMs were generated from ASTER and SRTM3 data and compared with each other and -for the Bernina Group-compared with the Swiss DHM25L2. Whereas ASTER DEM elevations are too high on average, SRTM3 DEM elevations are slightly too low. However, both DEMs are of good use for glacier delineation. The glacier mapping approach includes Landsat TM4/TM5-ratio images, multispectral and morphometric analysis. Results are satisfying for debris-free and larger debris-covered glaciers in both study areas. The next step should be an automated glacier mapping method.