Permafrost-Induced Hazard Zonation Using Satellite Data-Driven Multi-parametric Approach Employing AHP techniques in Alaknanda Valley, Uttarakhand, India

Permafrost is one of the key components of the mountain cryosphere. An increase in global air temperature is leading to the melting of permafrost. Degradation and thawing of permafrost may induce multiple effects on the landscape, such as ground subsidence, increased frequency of landslides and rock falls due to destabilization of permafrost-covered slopes, further harming the infrastructures like roads, bridges, dams, buildings, etc. Climate models can predict further degradation of permafrost in the high mountain regions due to an increase in air temperature, resulting in changes in the terrestrial ecosystem and frequent permafrost-induced hazards. In the past decade, the area under investigation has experienced multiple natural hazards like slope failures, landslides, rock-ice avalanches, etc. In this study, assessment and hazard zonation of geohazards associated with mountain permafrost was attempted using AHP (Analytical Hierarchical Process) based multi-parametric approach. Based on its hazard susceptibility, the study area was categorized into three zones, namely, low, moderate, and high. Their corresponding area were 1738.28 km2, 8945.77 km2, and 518.89 km2, respectively. The model output provided probable areas of hazard occurrence based on select topographical and climatic factors. Identifying regions with high hazard potential will help better understand the spatial distribution of such potentially hazardous sites within the study area, resulting in better mitigation and disaster management capabilities.