Geospatial Approach on Landslide Hazard Zonation Mapping Using Multicriteria Decision Analysis: A Study on Coonoor and Ooty, Part of Kallar Watershed, The Nilgiris, Tamil Nadu
Other literature type
Abdul Rahamana, S.
(issn: 2194-9034, eissn: 2194-9034)
Landslides are one of the critical natural phenomena that frequently lead to serious problems in hilly area, resulting to loss of human
life and property, as well as causing severe damage to natural resources. The local geology with high degree of slope coupled with
high intensity of rainfall along with unplanned human activities of the study area causes many landslides in this region. The present
study area is more attracted by tourist throughout the year, so this area must be considered for preventive measures. Geospatial
based Multicriteria decision analysis (MCDA) technique is increasingly used for landslide vulnerability and hazard zonation
mapping. It enables the integration of different data layers with different levels of uncertainty. In this present study, it is used analytic
hierarchy process (AHP) method to prepare landslide hazard zones of the Coonoor and Ooty, part of Kallar watershed, The Nilgiris,
Tamil Nadu. The study was carried out using remote sensing data, field surveys and geographic information system (GIS) tools. The
ten factors that influence landslide occurrence, such as elevation, slope aspect, slope angle, drainage density, lineament
density, soil, precipitation, land use/land cover (LULC), distance from road and NDVI were considered. These factors layers were
extracted from the various related spatial data’s. These factors were evaluated, and then, the individual factor weight and class
weight were assigned to each of the related factors. The Landslide Hazard Zone Index (LHZI) was calculated using Multicriteria
decision analysis (MCDA) the technique based on the assigned weight and the rating is given by the Analytical Hierarchy Process
(AHP) method. The final cumulative map of the study area was categorized into four hazard zones and classified as zone I to IV.
There are 3.56% of the area comes under the hazard zone IV fallowed by 48.19% of the area comes under zone III, 43.63 % of the
area in zone II and 4.61% of the area comes hazard zone I. Further resulted hazard zone map and landuse/landcover map are overlaid
to check the hazard status, and existing inventory of known landslides within the present study area was compared with the resulting
vulnerable and hazard zone maps. The landslide hazard zonation map is useful for landslide hazard prevention, mitigation, and
improvement to society, and proper planning for land use and construction in the future.