Landslide hazard and Risk Analysis in India at a regional scale

India has about 25% of its geographical area in the mountainous terrain exposing it to wide spread landslides triggered by mainly earthquakes and rainfall. The methodology for Landslide Hazard Zonation (LHZ) and Risk Analysis in India has been carried out in the present study by integrating various thematic layers namely Engineering Geology, Geotectonic (faults/ lineaments), Slope, Geomorphology, Landuse/ Landcover and Rainfall on Geographical Information System and the evolved vector layers subsequently correlated with the existing landslide inventory data. A numerical rating scheme for both the themes and the attributes of each theme has been developed using Information Value Based Method for detailed spatial data analysis. The hazard index map is'validated by correlating the landslide frequencies of different classes and a LHZ map is prepared exhibiting four zones, namely "unlikely/low hazard ", "moderate to low hazard", "high to severe hazard" and "severe to very high hazard". The risk assessment performed by integrating LHZ with the elements of vulnerability namely population density, road network and landuse /landcover depict that high population density regions are exposed to very high and high landslide hazard activities.