Application of fuzzy gamma operator in landslide susceptibility mapping along Yercaud ghat road section, Tamil Nadu, India

Abstract

The present study emphasizes the application of fuzzy operators in landslide susceptibility mapping along Yercaudghat road section in the state of Tamil Nadu, India. Yercaud is one of the important hill stations and tourist spot in Tamil Nadu. In recent times, it faces frequent landslide occurrences. There is a urgent need for detail study of landslides along the ghat road to prevent further slope failure. The study has been conducted through integrated remote sensing, GIS and field investigations. The existing landslide locations were collected from previous study and verified in the field. The slope gradient, slope aspect, relief, lithology, land cover, geomorphology, proximity to road, proximity to drainage and proximity to lineament were analyzed with the help of Survey of India topo map, published geology map and satellite data. The relationship between various causative factors with past landslide locations were compared using frequency ratio method. These frequency ratio values were normalized to get fuzzy membership values between 0 to 1. The parameter maps with membership values were integrated using fuzzy algebraic product, fuzzy algebraic sum and fuzzy gamma operators to get final landslide susceptibility map. The produced map was verified by comparing with existing landslide locations for calculating prediction accuracy. The fuzzy gamma operator (γ=0.975) showed the highest accuracy of 0.7895.