3. Landslide Disaster Management and Reduction: An Approach Through Remote Sensing and GIS

It is fact that, landslide disaster is the most significant hazard in the mountainous regions. These natural phenomena have resulted damage to engineering structures and loss to human life all over the world. Identification of potential instability problems in the initial stage of investigation may not only lead to delineation of landslide disaster zones but will also help to evolve possible remedial measures which may either be adopted to improve the slope stability condition or such problematic zones may be avoided for human settlement and any other developmental activities.

Remote sensing and GIS is a very useful tool in delineating area into various potential instability zones over a wide area. Information and data on all such aspects over a wide area can be abstracted by utilizing remotely sensed data and through GIS application tools. To understand the possible mechanism of landslide and relative contribution of various factors in inducing instability to slopes, it is required to study the past landslide activities. Later, the collected data has to be arranged and prepared into layered spatial GIS database for landslide hazard mapping. Some of the governing parameters; aspect, slope, curvature and elevation can be calculated from the digital elevation model (DEM) of the area, which can be obtained from the ASTER elevation data set. The slope material and land use/cover maps can be processed from Land sat + ETM satellite using different digital image processing procedures. Further, GIS based statistical and probability approach can be used to rate the governing parameters and then customized raster calculation can be applied to develop the landslide hazard map. Thus, Remote sensing and GIS application not only facilitate in identifying the potential landslide hazard over the area but it also helps in disaster management and reduction by provided information on possible degree of hazard with spatial distribution. Such information will be vital to mitigate the hazard and to foresee the anticipated adverse conditions which may adversely affect the safety of people and property.