GIS Based Landslide Susceptibility Mapping Using Analytic Hierarchy Process (AHP) for Uttarakhand, India

More frequent landslide events, especially in hilly regions such as Uttarakhand, Himachal Pradesh etc., is resulting into irreparable socio-economic losses each year. In this research work, a landslide susceptibility map (LSM) is generated by using Analytic Hierarchy Process (AHP) method in a GIS environment for Uttarakhand state of India. In previous such works, more or less similar thematic layers have been used for the LSM generation, which could be improved by increasing a few more landslide conditioning factors, yet important ones such as LULC, Geology, geomorphology, distance from roads, faults, rivers etc. Therefore, fourteen thematic layers (landslide conditioning factors), are utilized to detect the landslide susceptible areas. Weight for each factor is assigned depending on its impact on the landslide incidents. The LSM is derived using weighted overlay analysis based on AHP and categorized into three susceptible classes namely low, moderate and high. The results revealed that 15.42% of the study area is at low risk, 56.12% of moderate risk and 28.46% of high risk. The produced LSM is validated using LSM provided by BHUKOSH, a platform of data dissemination by Geological Survey of India (GSI). Such map would be helpful for planners and decision makers for land use planning and slope management in future.

1. Introduction

Landslide incidences in Himalayan region are about 30% of the total number of landslides in the world. Landslide damages the economic status, properties and also losses of lives all over the world [1]. Landslides are caused by meteorological, topographical, geo-environmental and geological factors and due to anthropogenic actions such as road constructions, open-pit mining, power house excavations, and land-use pattern changes [2]. Natural reasons of landslides consist of glacier melting, precipitation and earthquakes etc. Presently, the landslides phenomenon increased drastically due to impact of climate changes [3]. These factors motivated for thorough investigation and development of effective techniques for the susceptibility mapping. The present study focuses on the Uttarakhand, a state of India. From the survey reports, it is found that in 1998, more than 150 people were died due to landslide and a number of villages were affected in the state and more than 4000 causalities were recorded in June 2013 [4]. Landslide susceptibility map (LSM) is considered as an essential measure of landslide management of a landslide prone region [5]. LSMs could be implemented for minimizing effect of landslide on human kind, infrastructures, road networks, and land-use management [6]. Landslide susceptibility is defined as the probability of landslide occurrences by considering previous cases under the analogous geo-environmental conditions [7]. There are numerous techniques assisted by Geographic Information System (GIS) and Remote Sensing techniques that have been extensively used to generate LSMs by many researchers.