Landslide Susceptibility Analysis by Frequency Ratio Model and Analytical Hierarchical Process in Mirik and Kurseong, Darjeeling Himalaya, India

Landslide is a common phenomenon in the hilly region. The Himalayan region the one of the best examples of this type of landslide-prone region. Kurseong subdivision is the study area of this chapter. Landslide is a common hazard that creates an interruption in the normal human life. With the help of Susceptibility mapping, the landslide zones can easily identified. Analytical hierarchical process (AHP) and frequency ratio model (FR) are used to prepare the susceptibility map. About 77 past landslide inventories are traced for the study. Eighteen (18) inventories from the NASA Global landslide points, six (6) inventories from the field survey (2023) and fifty-three (53) inventories from Google Earth Pro (2010–2023) in Mirik and Kurseong. Twenty (20) landslide conditioning factors are taken into account for landslide susceptibility mapping, viz., slope, elevation, aspect, curvature, relative relief, Normalized Difference Vegetation Index (NDVI), Topographic Wetness Index (TWI), Topographic Ruggedness Index (TRI), drainage density and land-use and land-cover etc. Among the two models, the Analytical Hierarchical Process (AHP) has the highest accuracy (62.27%) as per ROC-AUC. From the predicted maps, it has been traced that Kurseong is experiencing high and very high landslide-prone areas. The landscape susceptibility map helps to figure out the prime governing factors behind a landslide in the study area. In addition, the said chapter addresses the sustainable mitigation process of the landslide in Kurseong that will contribute to further sustainable development in the area.