Macro Landslide Hazard Zonation Mapping - Case Study from Bodi – Bodimettu Ghats Section, Theni District, Tamil Nadu - India

Abstract

Landslide is a common natural hazard that usually occurs in mountainous areas. Rapid urban development and high traffic intensity movements have been hampered to a great extent by phenomenon of landslides. In Ghat section, vertical cuttings and steep slopes are induced slope failures. An assessment of landslide hazards is therefore a prerequisite for sustainable development of the hilly region. In the present study, Macro Landslide Hazard Zonation was carried out in the Bodi -Bodimettu ghats section, Western Ghats, Theni district. The slope spreads over an area of about 10.09 sq km encompassing Puliuttu Ar. sub-watershed. The study was made with help of different types of data including Survey of India topographic map, geology map, important inherent factors like lithology, structure, slope morphometry, relative relief, land use/land cover and hydrogeological conditions using Bureau of Indian Standard (BSI 14496 (Part 2):1998) and related thematic maps. Based on the thematic layers, landslide hazard evaluation factor (LHEF) and total estimated hazard (TEHD) were calculated and the macro hazard zonation map was prepared. Landslide Hazard Zonation (LHZ) of the terrain shows that out of 17 facets, facets 1 to 5 and 8 falls under Moderate Hazard zone category and facets 6, 7 and 9 to 17 under the High Hazard zone category. The field study with further analysis for hazard concluded that about 68% of the total area falls in the high hazard zone.

Landslide hazard assessment: recent trends and techniques

“…The slope facet map was considered as base map to prepare thematic data layers. Few attempts have been made to apply this method in several parts of India (Naithani 2007 ; Singh et al 2011 ; Champatiray et al 2007 and Kannan et al 2011 ).…”

Landslide hazard zonation mapping in ghat road section of Kolli hills, India

“…Macro-zonation map of landslide susceptibility is also generated for GaramauraSwarghat section of National Highway-21, India on 1:50,000 scale (Sharma and Mehta 2012). Similar kind of studies were carried out for ghat section of Yercaud hill slopes (Saranathan et al 2010), BodiBodimettu ghat section (Kannan et al 2011), and Kodaikanal hills (Saranathan et al 2012) in the state of Tamil Nadu, India. Based on the integration of qualitative and quantified weightages given to each factor at each grid, a micro-hazard zonation map of the area has been prepared for guiding the remedial actions required for preventing the landslides (Kishor Kumar et al 2012).…”

Terrain Factors Induced Slope Instability in CNG 37 – Ghat section, Panthalur, The Nilgiris

“…New statistical models, such as data models and fuzzy set theory, were also pragmatic [19] to assess the contributing effect of the factors. In this context, numerous scientists [20][21][22][23][24][25][26][27] attempted the routine of Geomatics in the methods of vulnerable mapping. In landslide-susceptible zonation, many authors have effort different methods to identify the zonation [28][29][30][31].…”