Prioritization of landslide hazard zones in parts of Darjeeling district, West Bengal, India - A RS and GIS approach
S. Sudhakar1, B. Sadasivarao2, B. Suryaprakasa Rao2 and V. Venkateswara Rao2
1Regional Remote Sensing Service Centre, Department of Space, Indian Space Research Centre, Indian Institute of Technology Campus, Kharagpur - 721 302
2Department of Geo-Engineering, Engineering College, Andhra University, Visakhapatnam - 530 017
In India, the incidence of landslides in Himalayas and other hill ranges is an annual phenomenon. The factors, which promote landslides, are (i) water (ii) slopes (iii) nature of rock (iv) structure (v) vegetation (vi) seismic activity. The essential conditions, which cause landslides, are lack of support in front and lubrication behind. Among natural hazards, mass movements are the most frequent and have the largess geographical distribution. Landslides alone cause greater loss of human lives and economic goods than any other single natural hazards. An integrated Remote Sensing and Geographical Information System approach is increasingly being used and recommended for landslide prone zoning. IRS - 1D LISS III satellite data were used to generated landuse/landcover, digital terrain model for sloe/aspect. The buffer of road and stream network was generated through on line digitization from the satellite data. The collateral data of lithology and soil maps were digitized and integrated with all the layers under study. In the present study, a quantitative approach for the landslide Hazard Zone (LHZ) mapping has been used, which more or less follows a numerical rating scheme called Landslide Hazard Evaluation Factor (LHEF) rating scheme. The LHEF rating scheme is based upon an empirical approach, which combines past experience, gained from the study of conditioning factors and their influence on slope stability. It is a numerical system based on major inherent conditioning factors of slope instability such as geology, Slope, relative relief, soil and existing landuse and landcover in the study area.
Page 1 of 1