Micro-Hazard Evaluation and validation of landslide in a part of North Western Garhwal Lesser Himalaya, India

A large number of natural factors control the occurrence of landslide phenomenon. However, anthropogenic activities, added with natural factors contribute handsomely to destabilize the hill slopes. The Himalaya being unique in its physiographic, tectonic and climatic characteristics coupled with many natural and man-made factors is inherently prone to landslides. Present article includes a study of certain parameters (as factors), selected as per their role in inducing landslides in one of the hazard prone regions of Northwestern Himalaya. A base map on 1:500 scale was prepared using high precision Total Station and GPS that was further divided into equal sized grids measuring 45m X 45m. The parameters such as lithology, structures, slope gradients, landuse and landcover and groundwater condition have been quantified and statistically analyzed for evaluating the landslide hazard potential of each of the grid.

Based on the integration of qualitative and quantified weightages given to each factor of each grid, a micro-hazard zonation map of the area has been developed for guiding the remedial actions required for preventing the landslides. The results were compared with results of geomechanical classification.i.e. RMR and SMR; of same site to support modified methodology. The map has been physically verified and was found to be mostly accurate.