Evaluation of ASTER GDEM with respect to SRTM for Chandra-Bhaga Basin, Indian Himalaya

Evaluation of ASTER GDEM with respect to SRTM for Chandra-Bhaga Basin, Indian Himalaya Pratima Pandey, G. Venkataraman Centre of Studies in Resources Engineering, IIT Bombay, Mumbai, India Abstract A digital elevation model (DEM) is a simple representation of a surface in 3 dimensional way with height as the third dimension along with x and y in rectangular axes. DEM has wide applications in various areas like disaster management, hydrology and water management, geomorphology and in urban development. Valuable information about a terrain can be inferred by exploiting a DEM in proper way. Study of DEM becomes very useful for studying mountainous terrain such as Himalaya which is otherwise hard to access due to harsh weather and inaccessibility. DEM can be generated by aerial photos, stereo images from satellites and toposheet. SRTM and ASTER GDEM are DEM which generated from satellite images and covers maximum parts of the earth. Shuttle Radar Topography Mission (SRTM) is a good quality DEM created in 2000 covering the globe between 600 N and 580 S with 3 arc second (90m) resolution. SRTM is available freely for research. ASTER GDEM is recently released global DEM created using ASTER scenes and made available to the world since June 2009 for carrying out research. ASTER GDEM covers land surfaces between 83°N and 83°S with estimated accuracies of 20 meters vertical data and 30 meters for horizontal data. So ASTER GDEM supposed to be more sophisticated. The present study aims at comparing the ASTER GDEM with the SRTM and ASTER DEM and evaluating its relative characteristics for undulating surface and glaciers of Chandra-Bhaga sub-basin situated in Lahual-Spiti district of Himachal Pradesh, Indian Himalaya. Once the characteristics of ASTER GDEM are evaluated for Himalayan terrain it can be used for various studies involving rugged terrain of Himalaya.