Techniques for Landslide Hazard Zonation - Application to Srinagar-Rudraprayag Area of Garhwal Himalaya

Abstract

Abstract The present work deals with the development and evaluation of landslide hazard zonation techniques which have been applied to parts of Garhwal Himalaya. The binary relationships between the factors and landslides have been determined. These relationships revealed the degree of susceptibility to landslide occurrence. The two techniques developed for landslide hazard zonation are the Subjective Rating Technique (SRT) and Objective Rating Technique (ORT). Although the SRT employs the inferred relationships between the landslide occurrence and the terrain factors to assign ratings to the factor categories, yet the rating assignment to the individual factors is subjective. The ORT reduces the impact of subjectivity in rating assignment, by deriving these from the frequency distribution of landslides. In this technique an attempt has also been made to judiciously classify the different hazard classes. Finally, the maps prepared from two different techniques have been validated and compared. The work presents a systematic approach to a comprehensive landslide hazard assessment of a large region.