TerraSAR-X/TanDEM-X data for natural hazards research in mountainous regions of Uzbekistan

Abstract

Accurate and up-to-date digital elevation models (DEMs) are important tools for studying mountain hazards. We considered natural hazards related to glacier retreat, debris flows, and snow avalanches in two study areas of the Western Tien-Shan mountains, Uzbekistan. High-resolution DEMs were generated using single TerraSAR-X/TanDEM-X datasets. The high quality and actuality of the DEMs were proved through a comparison with Shuttle Radar Topography Mission, Advanced Spaceborne Emission and Reflection Radiometer, and Topo DEMs, using Ice, Cloud, and Land Elevation Satellite data as the reference dataset. For the first study area, which had high levels of economic activity, we applied the generated TanDEM-X DEM to an avalanche dynamics simulation using RAMMS software. Verification of the output results showed good agreement with field observations. For the second study area, with a wide spatial distribution of glaciers, we applied the TanDEM-X DEM to an assessment of glacier surface elevation changes. The results can be used to calculate the local mass balance in glacier ablation zones in other areas. Models were applied to estimate the probability of moraine-dammed lake formation and the affected area of a possible debris flow resulting from glacial lake outburst. The natural hazard research methods considered here will minimize costly ground observations in poorly accessible mountains and mitigate the impacts of hazards on the environment of Uzbekistan.