Avalanche Hazard Mapping along Manali-patsio Road Axis (Himachal Pradesh, India) Using Advanced Geo-Informatics Techniques

Abstract

Avalanche occurrence is quite a hazardous and unpredictable natural phenomenon. A large number of factors that are associated with its occurrence make it quite difficult to assess hazard in hilly areas. There are two main groups of variables that define the avalanche hazard – meteorological conditions and terrain characteristics. Due to the stable nature along the time, terrain parameters are easier to map. The purpose of this work is to assess different geographical factors that affect the avalanches triggering and, by combining the derived information, to extract a map of the avalanche hazard that, in this case, is restricted to Manali-Patsio highway. To this purpose, GIS techniques have been used, by mixing vectorial information, digital terrain models and IRS LISS-III imagery. In this paper, multi-criteria have been proposed as a technique for avalanche hazard mapping. Five avalanche conditioning factors (slope, aspect, land cover, elevation, and curvature) were taken as inputs. The ratings were given to each category of factors contributing to avalanche and weightages were decided for each factor after consulting experts in this field. The results were verified by back analysis. In back analysis, registered avalanche Atlas (SASE, Chandigarh) of the study area is taken as input and criteria for avalanche triggering were extracted. Then using these criteria, a model was generated and results were validated.

Keywords: Avalanche hazard, GIS, multi-criteria, remote sensing, back analysis