Slope stability analysis for landslide hazard zones between mettupalayam and coonoor ghat section tamil nadu india

Abstract

Landslide is an important devastating natural geological hazard in mountainous environment that causes damage to natural as well as social environment It is a hazard caused mainly due to immature geological factors coupled with other triggering factors In India landslide is one of the most significant hazards that affects the different mountainous regions every year during rainy season Previous study reported that in India landslides are highly risky at ten hilly states such as the Himalayas the North East India the Nilgiris the Eastern Ghats the Western Ghats including the union territory of Pondicherry Mahe The location for the present study is situated between Mettupalayam and Coonoor Ghat section The major objectives of the present study are to identify potentially vulnerable cut slopes in the landslide prone areas and to evaluate Factor of Safety FOS in rock slopes as well as soil slopes This study also aims to understand the failure analysis in the soil slope in different saturation conditions by Circular Failure Charts CFC and to provide proper remedial measures for vulnerable cut slopes The present study was carried out in two phases In the first phase Qualitative and Quantitative approaches were adopted for preparation of landslide hazard zonation maps In the case of Quantitative method Total Hazard Evaluation Factor THEF was applied for evaluation of the Landslide Hazard Zonation LHZ and landslide inventory map revealed that 85 14 and 1 of landslide were falling in the High Moderate and Low Hazard respectively In the Qualitative method the Landslide Susceptibility Zonation LSZ was prepared by using weighted overlay analysis for nine causative factors considered for Landslide Hazard Index LHI Landslide inventory map shows that 81 36 15 25 and 3 4 of landslide were falling in the Very High to High Moderate and Low Hazard respectively The comparison of these two models depicts that Quantitative method was attaining more accuracy than Qualitative method