Landslide Susceptibility Zonation Mapping Using Multi-Criterion Analysis-CNG 37 Ghat Section, Nadugani, Gudalur Taluk, The Nilgiris-Using Geological Factors

Landslides occur in hilly regions that are prone to activities of urban development, agricultural activities, construction of dams and road and railway network. The slope instability in hilly slope areas is due to construction activities, clearing the natural vegetation, unplanned resort development tourist activities, etc. The landslide susceptibility mapping is an effective tool for the development of hilly areas to analyse the slope stability along the road network. This paper attempts a GIS based multi-criterion methodology to identify landslide susceptibility zonation in CNG (Calicut-Nilampur-Gudalur)-37 ghat section in Nadugani, Gudalur taluk, The Nilgiris district. The environmental geological factors used for the landslide susceptibility analysis include, geology, weathering thickness, geomorphology, lineament, lineament density, lineament intensity, lineament buffer and slope. By applying and integrating the multi-criterion weights using ArcGIS software, a landslide susceptibility zonation is obtained and the study area is divided into five classes which include very low, low, moderate, high and very high regions. The susceptibility zonation map shows that 1.60% in Very low, 18.49% in Low, 40.39% in Moderate, 33.78% in high and 5.74% very high hazard zone. The landslide susceptibility zonation map is validated with landslide points which were collected from the field using high performance GPS. According to landslide inventory details 1.25% is located in very high, 24.27% in high, 55.66% in moderate, 18.83% in low and 0% in very low hazard zones.