Citation

Vaani N, Sekar SK. Disaster Adv. 2012; 5(4): 171-176.

Copyright

(Copyright © 2012, Shankar Gargh)

DOI

unavailable

PMID

unavailable

Abstract

Landslides are the most frequently occurring events in the region of Nilgiris, especially during the monsoons for many decades. Such events are known for its damages that occurred on cut slopes or embankments alongside roads and highways in mountainous areas. Few landslides also occur in residential areas, causing death to human beings. So, it becomes highly essential to plan and mitigate the occurrences. Many efforts are being made to assist administrative authorities and local planners in identifying such vulnerable areas in hilly terrains which derive Landslide Hazard Zonation (LHZ) and Vulnerability map of concerned region/locality, like the National LHZ atlas/Vulnerability atlas at Macro level for India. In this study an attempt is made to generate a regional level LHZ map for Nilgiris district of Tamil Nadu, India, taking into account some of many causative and triggering factors like Slope, Rainfall, Geology and Landuse which are considered to be predominant in that area. One of the multi-criteria decision making techniques is Analytical Hierarchy Process (AHP), which provides a systematic approach for assessing and integrating the impact of various factors and it was used for preparation of LHZ map. The weightages derived through the process were used in "weight-averaging" the map layers to get LHZ map as an output for this region. Vulnerability analysis was carried out using the map overlay technique in GIS to identify and report vulnerable roads and settlements. Landslide Hazard Zonation (LHZ) map was integrated with Transportation (Road) Network map and Settlements map which resulted in generation of maps showing varying degree of vulnerability on roads and settlements. The results were compared with landslide inventory map and proved efficient in areas of high hazard potential. It was found that 1235 km of roads are highly vulnerable to landslides. Villages like Burliar, Kengarai, Kanakarai, Kinnakkorai, Mulligoor, Nanjanad, Thummanatti and Nellakotta need immediate attention for retrofitting of slopes.