Pixel based terrain analysis for Landslide Hazard Zonation, a case study of Tehri reservoir region, Uttarakhand, India

A methodology for delineation of landslide hazard zones using Terrain parameters, frequency ratio and arithmetic overlay approach in GIS environment, is presented. Temporal remote sensing data including Digital Elevation Model (DEM) had been used for preparation of landslide causative factors. Terrain parameters such as: slope, aspect, relative relief, topographic wetness index (TWI), and stream power index (SPI), were derived and their influence on landslide had been performed using landslide frequency ratio. Other landslide causative factors: Land use/Land cover, drainage, lithology, and photo-lineaments were generated from remote sensing multispectral data by applying different image processing techniques. Ancillary data including field observations were incorporated in GIS platform. Landside frequency ratio for each factor´s attribute was calculated. Integration of conditioning factors was done by using arithmetic overlay, which had resulted a pixel based hazard index map, which was further classified and validated.