Macro-zonation of landslide hazard in the environs of Baira dam project, Chamba district, Himachal Pradesh

摘要

Landslides are the most common geo-hazard in hilly terrain. Developmental activities have been hampered to a great extent by phenomenon of landslides. The construction of Baira dam on River Baira remained suspended nearly for two years on account of a major landslide. An assessment of landslide hazard is, therefore, a prerequisite for sustainable development of the region. The present study deals with macro-zonation of landslide hazard in an area of about 100 sq km on 1:50,000 scale encompassing Baira dam. A numerical weightage to the prime causative factors of slope instability viz. lithology, structure, slope morphometry, relative relief, land use and groundwater conditions are assigned as per the scheme approved by Bureau of Indian Standard for the purpose of landslide hazard zonation. The area depicts zones of different instability. The identified hazard zones compared with isopleth mapping of landslide intensity in the area show mismatch of the hazard zones, This anomaly calls for further rationalization of the numerical weightages of the assigned factors.