GIS-Based Risk Assessment of Debris Flow Disasters in the Upper Reach of Yangtze River

摘要

This paper discussed theory and methodologies of debris-flow risk assessment and established an implementation process according to indicators of debris-flow hazard degree,vulnerability,risk degree,etc. Among these methodologies,historical and potential hazard degree was comprehensively considered into hazard assessment and hazard index was presented to indicate the debris-flow hazard degree. Regarding debris-flow vulnerability assessment,its statistical data and calculating procedure were based on the hazard-degree regionalization instead of administrative divisions,which improved the as-sessing scientificity and precision. These quantitative methodologies inte-grated with Geography Information System(GIS) were applied to the risk assessment of debris flows in the upper reach of Yangtze River. Its results were in substantial agreement on investigation data and the actual distribution of debris flows,which showed that these principles and methodologies were reasonable and feasible and can provide basis or reference for debris-flow risk assessment and disaster management.