Landslide Hazard Zonation in the Ashwani Khad Watershed, Himachal Pradesh, India: An Analytical Hierarchy Process and GIS Approach

LandslidesLandslide represent aLandslide hazard zonation prominent natural disaster in the state of Himachal Pradesh, India. These landslides can be triggered by both natural and human-induced factors. The proliferation of construction activities on precarious slopesSlope, incapable of withstanding even minor seismic activity, exacerbates the susceptibilitySusceptibility to landslides. In the context of mountainous regions like Himachal Pradesh, sustainable development necessitates the implementation of strategies that consider the existing terrain instabilities to mitigate geoenvironmental risks. This chapter focuses on the Himalayan mountainous region of Himachal Pradesh, specifically the Ashwani Khad WatershedWatershed, and a tributary of the River Giri, which, in turn, flows into the Yamuna RiverYamuna River. The study area spans from latitudes 30°51′57″ N to 31°7′26″ N and longitudes 77°5′37″ E to 77°15′37″ E. The altitude in this region varies from 845 m at its lowest point to 2696 m above sea level at its highest point. To assess and map landslideLandslide hazards, this chapter employs the analytical hierarchy process (AHPAnalytical Hierarchical Process) in conjunction with Geographic Information SystemGeographic Information System (GIS) (GIS) technology. Eight primary factors are considered in the analysis, which include slopeSlope, aspect, geologyGeology, land use land cover, relative reliefRelative relief, structural characteristicsStructural characteristics, precipitationPrecipitation, and drainage patternsDrainage patterns. Weights for these factors and their respective classes are determined using the AHPAnalytical Hierarchical Process methodologyMethodology. A landslideLandslide hazard zonationLandslide hazard zonation (LHZ) map is then generated by combining the weights of each factor through a weighted sum technique. The LHZ map, developed through the AHPAnalytical Hierarchical Process approach, reveals that areas with high to very high landslide hazard classes constitute 25.44% of the total geographical area within the Ashwani Khad WatershedWatershed. In contrast, moderate and very low to low hazard zones cover 26.09% and 47.47% of the total geographical area, respectively. These hazard zones provide valuable information for land use planning, infrastructure development, and disaster mitigation efforts in the region.