Journal of Geography, Environment and Earth Science International 16(4): 1-14, 2018; Article no.JGEESI.42875 ISSN: 2454-7352 Landslide Hazard Zonation (LHZ) Mapping Using RS and GIS Techniques: A Case Study of Kumbur River Basin of Kodaikanal Taluk, Dindigul District, Tamilnadu, India R. Mahesh1*, R. Baskaran1 and R. Anbalagan2 1Department of Industries and Earth Sciences, Tamil University, Thanjavur, Tamil Nadu, India. 2Department of Earth Science, Indian Institute of Technology, Roorkee, India. Authors’ contributions This work was carried out in collaboration between all authors. Author RM designed the study, performed the statistical analysis, wrote the protocol and wrote the first draft of the manuscript. Authors RB and RA managed the analyses of the study. All authors read and approved the final manuscript. Article Information DOI: 10.9734/JGEESI/2018/42875 Editor(s): (1) Badiora Adewumi Israel, Dept. of Urban & Regional Planning, College of Environmental Design & Management, Wesley University, Nigeria. (2) Wen-Cheng Liu, Department of Civil and Disaster Prevention Engineering, National United University, Taiwan and Taiwan Typhoon and Flood Research Institute, National United University, Taipei, Taiwan. Reviewers: (1) Monalee A. delaCerna, Surigao State College of Technology, Philippines. (2) Chia-Feng Hsu, National Taiwan Ocean University (NTOU), Taiwan. Complete Peer review History: http://www.sciencedomain.org/review-history/25887 Received 29th May 2018 Accepted 2nd August 2018 Original Research Article th Published 14 August 2018 ABSTRACT Landslide is one of the disasters which lead to large-scale damage to properties and life. It frequently occurs in hilly regions like Himalaya, Western and Eastern Ghats. In Tamil Nadu, most of the landslides are often seen in Blue Mountains, Kodaikanal and Yercaud, occasionally in the other areas. Kodaikanal hills are facing two major problems viz. urbanization and environmental degradation. In this study, the landslide hazard zonation maps are prepared based on the causative factors of slope instability, namely thick soil accumulation, lithology, geological structure drainage density, slope morphometry, relative relief, land use and land cover and hydrogeological conditions in facet wise by using BIS code: IS 14496 (Part-2) – 1998. As per BIS classification method, Kumbur River Basin area, the distribution pattern of Landslide Hazard Zonation (LHZ) _____________________________________________________________________________________________________ *Corresponding author: E-mail: [email protected]; Mahesh et al.; JGEESI, 16(4): 1-14, 2018; Article no.JGEESI.42875 indicates that in the total 82 facets, 3 facets come under very high hazard category, 17 facets come under high hazard category, 40 facets are present in moderate hazards and remaining 25 facets come under range in low hazard. Keywords: Landslide Hazard Zonation; Kumbur River Basin; RS and GIS; Kodaikanal hills. 1. INTRODUCTION susceptibility zonation (LHZ) map for the upland catchment of river Kumbur Kodaikanal Taluk, Kodaikanal hills have been the centre of Tamilnadu, India using GIS techniques by urbanization in the past few decades. The recognizing and mapping the paleo-slide frequent problems in Kodaikanal area are mainly locations and the associated terrain attributes road blockades due to slope failure along the [6]. The terrain parameters such as roadside during rains leading to smaller and geomorphology, drainage density, soil type, soil medium slide due to unplanned construction, thickness, land use, Normalized Difference drainage and agricultural activities. The Vegetation Index (NDVI), slope stability aspect, construction activities in the form of resorts, relative relief, slope length, profile curvature, plan hotels, houses, cottages and other structures curvature, flow path length and topographic have resulted in a large-scale deforestation. The wetness index were selected for this study tourist's inflow has increased alarmingly in the [4] and [5]. Using GIS techniques and Weights of past few years, evidenced by a large number of Evidence (WofE) model, the present research new resorts in and around Kodaikanal demonstrates the application of weighted overlay municipality. analysis method to produce the landslide hazard zone map for Kumbur River Basin [13] Landslides are one of the natural disasters which and [14]. account for huge damage to properties in terms of direct and indirect risk [1]. The term “landslide” 2. METHODOLOGY basically means a slow to rapid downward movement of instable rock and debris masses 2.1 Study Area aided of gravity which can be categorized into various types on the basis of slope failure Kodaikanal is situated in the southern tip of the characteristics [2]. Increase in population and upper Palani hills in the Western Ghats and a rapid urbanization has led to the expansion of long history of hill resorts in Dindigul district, construction activities in hilly terrain and has Tamil Nadu. Mannavanur, Poondi town is catapulted frequency of landslides to dramatic situated in the central part of the Study area. It proportions in recent decades [3]. The present has a total geographical area of about 104.7736 study areas, Kumbur River Basin of Kodaikanal sq. km and extent from 10o 07’00” N to 10o 16’ Taluk are prone to landslides and were affected 00” N latitude and between 77o 16’ 00” E to 77o by frequent landslides in the past. In October 21’ 00” E longitude. The sub-watershed is partly 2011, heavy rain resulted in landslides at covered by 58F/7sw, 8nw, and 8sw of Survey of Kumbur River Basin, high range areas of India Toposheets. Dindigul district bordering Tamilnadu State, caused massive loss to crop and property. The base map incorporating main details and Similarly, in October 2012, inclement weather reference information was prepared from above condition brought heavy-rain at Mannavanur, said toposheets. Using land use, soil and rainfall Poondi, on various areas of Kodaikanal taluk. data, runoff the potential of each facet is Damage on farmland and houses were reported. identified and it is a supplement to prepare Traffic was disrupted on several arterial roads, landslide hazard zonation [15,16] and [17]. including Mannavanur and Poondi-Kodaikanal highway road, as the water level rose drastically 2.2 Geology and Structural Discontinuity in Kumbur River [4,5] and [6]. The study area is underlain of Archean age, The reliability of the hazard analysis depends on Charnockite and Gneisses are being the major various factors and methods deployed [7] and formation. A major portion of Study area largely [8]. Various methods of analysis have been covered by Charnockite rock and it is covered by proposed by many different authors [9,10,11] and about 90% of the taluk area. The remaining area [12]. Saranathan et al prepared landslide comes under Hornblende Biotite gneiss. One of 2 Mahesh et al.; JGEESI, 16(4): 1-14, 2018; Article no.JGEESI.42875 the gneissic bands is running along Mannavanur- or wedge mode evaluated and possible failure is Kumbur road and Kilavarai-Natampatti area and obtained. another small batch of the gneissic band is seen in Poondi area. Fig. 2 shows Geology and 2.3 Rainfall structure of the study area, derived from Geological Survey of India, Chennai and The precipitation occurs during from season viz. structure features extracted from aerial South-West monsoon from June to September, photographs, 1985 and satellite image IRS-1C, North-East monsoon across October to LISS III, March 2008, National Remote Sensing December, winter falls between January and Centre, Hyderabad (with limited field check) [18] February and summer showers from March to and [19]. May. The period from May to November is the chief rainy season during which period about 70 The structural discontinuity in relation to the to 80% of annual rainfall is received. The area slope angle and direction has a greater influence gets rain from two monsoon seasons, the south- on overall stability condition of the area [20]. The west monsoon and the north-east monsoon. The structural discontinuities were covered in 82 south-west monsoon starts in June and ends in facets and they are furnished in Table 3 and September. The north-east monsoon season is these observed structural details are plotted on from October to November. The highest rainfall stereo-net (Fig. 3). As per the relationship of was recorded at Mannavanur and the lowest structural discontinuity with slope, the numerical recorded at Kilavarai. The average rainfall is ratings for each of the situations in either plainer around 102.6 mm per year. Fig. 1. Location Map of the study area 3 Mahesh et al.; JGEESI, 16(4): 1-14, 2018; Article no.JGEESI.42875 Fig. 2. Geology and Structure Fig. 3. Stereo Net 4 Mahesh et al.; JGEESI, 16(4): 1-14, 2018; Article no.JGEESI.42875 Table 1. List of structural discontinuities Sl. No Latitude – Longitude Structural Details Remarks 1. 10o 11. 30 N - 77o 20. 06 E J1 Strike N 105o Poondi Dip Direction N 35o W Dip 40o 2. 10o 11. 46 N - 77o 19. 31 E J1 Strike N 50o Nattampatti Road Cut Dip Direction N 20o E Dip Amount 90o J2 Strike N 20o Dip Direction N 60oE Dip Amount 90o 3. 10o 12. 09 N - 77o 19. 11 E J1 Strike N 15o Pollur Road cut Dip Direction N 80oE Dip Amount 90o J2 Strike N 80o Dip Direction N20oW Dip Amount 90o 4. 10o 12. 19 N - 77o 19. 21 E J1 Strike N 30o Pollur agriculture Dip Direction N 60o W Dip Amount 50o 5. 10o 11. 68 N - 77o 19. 02 E J1 Strike N 15o Kilavarai Road cut Dip Direction N260oW Dip Amount 90o J2 Strike N 5o Dip Direction N250oW Dip Amount 35o 6. 10o 12. 42 N - 77o 18. 79 E J1 Strike N 10o Kilavarai Agriculture Dip Direction N 260o E Dip Amount 40o 7. 10o 11. 89 N - 77o 20. 04 E J1 Strike S 200o Poondi Agriculture Dip Direction N 100o E Dip Amount 90o 8. 10o 11. 91 N - 77o 20.