160 ECO-CHRONICLE A GEOSPATIAL APPROACH FOR LANDSLIDE SUSCEPTIBILITY ASSESSMENT IN MALAPPURAM DISTRICT, KERALA, INDIA Krishnakumar, K. N 1 ., Sayyida Rasala Hashmi, T. A 2 ., Jesiya, N. P 3 and Girish Gopinath 3,4 1 Maharajas College, Ernakulam, Kerala. 2 Department of Marine Geology and Geophysics, Cochin University of Science and Technology, Cochin, Kerala. 3 Geomatics division, Centre for Water Resources Development and Management (CWRDM), Kunnamangalam, Kerala. 4 Department of Remote sensing and GIS, Kerala University of Fisheries and Ocean Studies, Cochin, Kerala. Corresponding author: ggcwrdm@gmail.com ABSTRACT Vol. 14, No. 2, June, 2019 ISSN: 0973-4155 ECO CHRONICLE PP: 160 - 166 RNI No. KERENG/2006/19177 Landslide susceptibility analysis, a precursory stage in landslide hazard and risk assessment was carried out in the study using geospatial techniques. Malappuram district which consist of highly undulating terrains including ecologically sensitive segments of Western Ghats selected for the analysis. Five major Landslide influencing factors such as geology, geomorphology, slope, soil and landuse/landcover were delineated in the ArcGIS platform and generated suitable weights for each of these factors based on their influence on landslide occurrence. The resultant susceptibility analysis pointed out that the 13.46 % of the total area is the most landslide vulnerable and about 17%, 3% and 66% were contributes unstable, moderately stable and highly stable terrain respectively. The prediction accuracy ensured through the validation analysis using recent landslide occurrence and resultant map will enable to reduce the future landslide hazards in zone through the appropriate and adaptive land use planning and innovative management techniques. Keywords: Landslide susceptibility; GIS; Stability; Malappuram INTRODUCTION Landslide is one of the natural catastrophes which cause adverse effect on human lives and also cause damage to communication routes, human settlement, agricultural and forestland. It is the movement of a mass of rock, debris or earth down the slope (Cruden, 1991) when the shear stress exceeds the shear strength of the material. In the hilly terrains of India including the Himalayas, landslides have been a major and widely spread natural disaster the often strike life and property (Dortch et al. 2009; Parkash, 2011). Approximately 15% of land area of the country is vulnerable to landslide hazard. Out of these 0.098 million km 2 is located in north eastern region and rest 80% is spread over Himalayas, Nilgiris, Ranchi Plateau and Eastern and Western Ghats (Geological Survey of India, 2006). In Kerala, landslides are common in hilly ranges and caused many deaths and major destructions. Among the 14 districts of Kerala, 13 are prone to landslides and in which Idukki is the worst affected with 217 landslides (Geological Survey of India, 2006, Kuriakose et al. 2009). Kerala receive high amount of rainfall during monsoon which make the slopes of hilly areas vulnerable to landslide. The heavy rain from the monsoon had saturated hill side of the Ghats during summer months triggering landslide. The progressive weakening of slope materials by slow natural process such as continuous weathering and tectonic forces (Sajinkumar et al. 2011) enhance the slope failure. Failure of hill slope modifications carried out for developmental activities and plantations in disaster prone areas are a major concern in rain related events. The highlands of Kerala experiences several types of landslides, of which debris flow are the most common (Kuriakose et al. 2009). Rainfall-triggered landslides are difficult to monitor due to lack of adequate data (Omman et al. 2018). Remote sensing serves as the best practical tool for mapping, monitoring and analysis with reasonable