Landslide Hazard Zonation and Vulnerability Assessment Of Western Ghats - A Case Study in Devikulam Taluk of Idukki District, Kerala

Landslide hazard analysis and mapping can provide useful information for catastrophic loss reduction, and assist in the development of guidelines for sustainable land use planning. The present analysis is an attempt to demarcate landslide hazard zones in Devikulam Taluk of Idukki in GIS platform. The investigation incorporated Geomorphology, Geology, Drainage density, Slope, Soil and Land use layers. These thematic layers were overlaid with appropriate weights to generate landslide hazard zones in Devikulam taluk. The study area falls in the ecological sensitive Zone of the Western Ghats. It has a highly undulating topography with ridges intervening valleys, high peaks, and steep slopes leading to narrow gorges like valleys with gradient streams and plateau. The study area result could be classified into five vulnerable zones namely Class I, Class II, Class III, Class IV, and Class V. Among them Class I is a very low vulnerable zone while Class V is very high vulnerable zone. Analysis revealed that 43.72% of the area falls under Class V, 25.55% of area falls under Class IV, 23.79% of area falls under Class III, 6.12% of area falls under Class II, 0.01% of area falls under Class I. When on superimposing the pre-occurred landslide locations with our result, we find that most of the landslide Vulnerability locations fall under Class V and Class IV.