Abstract
The potential of satellite remote sensing for high-mountain hazard assessments has been increasingly recognized in recent years. So far, mainly satellite sensors such as Landsat-5/7, SPOT-3/4, or ASTER have been used for investigating glacial hazards. The recent emergence of commercial satellite sensors with very high spatial resolution in the sub-metre range opens new perspectives for applications in the area of natural hazards. Satellite sensors such as IKONOS, QuickBird or Orbview-3 provide imagery comparable to aerial photography. Presumably due to the recent emergence of these satellite sensors and the high image acquisition costs, studies on the application of QuickBird and IKONOS data for high-mountain hazards are largely missing yet. This contribution therefore aims at evaluating the potential of QuickBird and IKONOS imagery for high-mountain, in particular glacial, hazard assessments. QuickBird imagery was used in relation with a major rock-ice avalanche in the Northern Caucasus in 2002 for detailed analysis of avalanche formation and dynamics, for assessment of ice dam, lake and related flood hazards, and for mass movement model support. IKONOS imagery was used in the Swiss Alps for identification of potentially unstable debris slopes and debris flow formation in combination with digital terrain modelling. Limitations of this type of satellite data for high-mountain hazard studies are related to the high acquisition cost, and problems to collect sufficiently accurate ground reference data for geocorrection. However, this study shows that for the demonstrated applications in remote areas the achieved absolute ground positional error of 20-30 m allows of reasonable results. It is concluded that the QuickBird and IKONOS imagery are powerful tools for high-mountain hazard assessments with a high potential in the future.
Huggel, Christian