GIS Based Slope Analysis for Landslide Hazard Zonation Mapping, Nilgiri Mountains, South India

要旨

Landslides are the major disasters crippling the mountain systems all over the world. Landslide Hazard Zonation maps (LHZ) were prepared by many workers using single or combination of terrain/geo-system parameters by assigning varying degrees of significance to different parameters . Hence these LHZ models vary substantially from each other. However, the authors inferred that the slope , which is one of the vital parameters controlling the landslides, have been either analysed in conjunction or given equal weightage with other geo-system parameters, thus leaving less scope for understanding the actual contribution of slopes in landslides and the related remedial measures therefrom. So, the present study was undertaken to analyse the slopes in detail by classifying it into over 46 classes using the advanced virtues available with GIS. From the same,a new technique was developed for LHZ mapping for a part of Nilgiri mountains , which is known for landslides since decades.