Geoinformatics based landslide vulnerable zonation mapping using analytical hierarchy process (AHP), a study of Kallar river sub watershed, Kallar watershed, Bhavani basin, Tamil Nadu

Abstract

Landslide is one of the most horrible catastrophic events among the various disasters to the human society, which is caused by the influence of various phenomena of the earth, atmospheric and anthropogenic activities individually or collectively. Landslides not only affect the loss of human life, but also cause economic burden on the society. In the very recent past Geoinformatics based decision support system and techniques are being used for landslide hazard mapping and zonation maping. It enables the combination of different data layers at varies levels. In the present study, Analytical Hierarchy Process (AHP) method was applied to prepare landslide Vulnerable Zonation mapping for Kallar River Sub Watersheds, Bhavani basin, Tamil Nadu by taking ten relevant factors. All these factors were converted into layers by extraction of related spatial data. The Landslide Vulnerable Zonation Index was calculated using the weighted linear combination technique based on the assigned weight and the rating given by using AHP method. Finally the study area was brought under five classes of vulnerable zones. In this 33% of area occupied by very high and high zones followed by moderate zone covers 41 and 26% of the area under very low vulnerability and low vulnerability zones. Further resulted vulnerable zone map and land use/land cover map were overlaid to check the vulnerability status by comparing the previous significant landslide locations. The landslide Vulnerable Zonation map is useful for landslide hazard prevention, mitigation, and improvement to society and implementation of appropriate landuse planning.