Multi-hazard susceptibility mapping for disaster risk reduction in Kargil-Ladakh Region of Trans-Himalayan India

Mountainous regions are prone to multiple hazards, which often result in loss of life and damage to property. Despite being prone to multiple hazards, the Himalayan Region has a scarcity of multi-faceted hazard studies. In this backdrop, present study aims to develop a multi-hazard susceptibility map for the Kargil-Ladakh Region of Trans-Himalayas using a standard three-step procedure which includes (i) hazard identification and inventorying; (ii) selection of conditioning factors; (iii) generation of individual and multi-hazard susceptibility maps. The identification and profiling of three major hazards namely, flash floods, landslides and snow avalanches, were followed by inventorying of individual hazards. Geo-spatial tools and frequency ratio (FR) method were  used to generate individual and multi-hazard susceptibility maps by selecting a set of conditioning factors and combining them with the hazard inventories. The results reveal that in single-hazard scenario, landslide susceptibility is highest at 44%, while as combined susceptibility for landslide and snow avalanche in double-hazard scenario was found to be 58%. In triple-hazard scenario involving landslide, snow avalanche and flash flood, combined susceptibility was  around 39% for the region. The validation of results using receiver operating characteristic curve (ROC) depicts an area under curve (AUC) values of 83%, 81% and 71% for snow avalanches, landslides, and flash floods, respectively, which lies within acceptable limits. The findings also indicate that agriculture, built-up and infrastructure developments are expanding within the high hazard-susceptible zones, emphasizing a need for implementation of disaster risk reduction (DRR) strategies in this multi-hazard prone Trans-Himalayan Kargil region.