Landslide hazard analysis of Central Himalayan region using Remote Sensing and GIS

Biswajit Pradhan, MTech(Civil Engineering)

ABSTRACT

Landslides are among the most common natural hazards in mountainous regions, triggered mainly under the influence of earthquakes and/or rainfall. Based on the spatial and temporal distribution of the landslides and their triggering factors, it is possible to identify susceptible areas. Remotely sensed data provide a synoptical view of large areas on a temporal basis for evaluating the surface conditions before and after landslide events. Terrain information, such as, landcover, geology, geomorphology and drainage could also be derived from, and the existing thematic information can be updated to enable the quantification of human interface of the Earth's surface. Spatial and temporal multi-layered information required to access landslides hazard susceptibility. The manual method of data combination for targeting potential zones susceptible to landslide hazards is time consuming. The present study highlights the usefulness of remotely sensed data and knowledge based geographical information systems for the collection, integration and analysis of the existing data. It also pertains the preparation of mapping of the landslide potential zones in a GIS environment along the Central Himalayan Region. On the basis of geological and morphological analyses it is further suggested that the combined impacts of the crushed nature of bed rock (due to the neo-tectonic activities), heavy rainfall and lack of vegetation cover cause persistent recurrence of landslides along this region. The role of earthquakes has been also discussed.