Landslide Susceptibility Mapping of East Sikkim Employing AHP Method

The occurrence of landslides is a frequent phenomenon in the hilly terrain of the Indian Himalayan region leading to severe environmental and socio-economic issues by distorting ecological balance and damaging human lives and property. The present work intends to identify the landslide susceptibility zones of Sikkim Himalaya using the ensembles of important knowledge-driven technique, i.e., Analytical Hierarchy Process (AHP) with Landslide Numerical Risk Factor. The Shuttle Radar Topography Mission (SRTM) DEM, Landsat 8, and GSI datasets were used. The landslide inventory map has been considered as the dependent factor and the geo-environmental factors like rainfall, slope, aspect, altitude, geology, soil texture, distance from the river, lineament, and road, Stream Power Index (SPI), topographic wetness index (TWI), Topographic Roughness Index (TRI), and Sediment Transport Index (STI), Normalized Difference Vegetation Index (NDVI) have been considered as independent factors. A landslide susceptibility map was prepared based on the AHP method and classified into high, moderate, and low-risk zones in a GIS environment. Results reveal that, about 29% of areas highly susceptible to landslide and past landslide inventories were also overlaid to observe the accuracy of susceptibility mapping.