Satellite remote sensing procedures for glacial terrain analyses and hazard assessment in the Aoraki Mount Cook region, New Zealand

摘要

Hazards originating within glacial environments have received limited attention in New Zealand. In view of rapidly changing environmental conditions and the need for ongoing monitoring, overseas studies have recognised the importance of remote sensing procedures to support related hazard investigations. The initial goal for regional hazard studies is the identification of potential source areas on the basis of terrain analyses. Following a review of remotely sensed imagery and its application in glacial studies, several methods are applied here to map glacial ice, lakes, and debris accumulations in the Mount Cook region of New Zealand using freely available ASTER imagery. A new method for mapping turbid and clear water glacial lakes is presented, and the first application of a method for mapping debris accumulations at the regional scale appears promising for debris flow hazard investigations. Analyses of terrain changes reveal that a 20% expansion in lake area has continued over recent years, increasing the hazard potential from mass movement induced outburst flooding. A framework for the assessment of hazard potential in the region is introduced, requiring the integration of terrain analyses presented here with permafrost distribution modelling, geological mapping, and topographic analyses.