Identification of Potential Landslide Susceptible Area in the Lesser Himalayan Terrain of Nepal

Kismat Pokhrel,Bharat Prasad Bhandari

doi:10.4236/gep.2019.711003

Kismat Pokhrel, Bharat Prasad Bhandari

Open Access

https://doi.org/10.4236/gep.2019.711003

Copy DOI

Abstract

Landslide susceptibility mapping is a very important tool to identify potential landslide-prone areas. In this work, weight of evidence method is applied to obtain landslide susceptibility assessment. Weight of evidence model is commonly applied in the landslide study as it is widely acceptable and easy to use. The objective of this paper is to prepare the landslide susceptibility map of Lung Khola catchment, Pyuthan District of Nepal. Altogether, 84 landslides were identified after landslide inventory. The thematic layers of all causative factors and existing landslides are prepared in Arc GISsoftware. Mainly, Digital Elevation Model (DEM) based causative factors and field data were used to prepare the data layers of the causative factors. In this research, 8 intrinsic factors were used for the landslide assessment. South East and East facing aspects, slope >60 degrees, elevation ranges 1300 - 1700 m, phylitic rocks and agricultural land followed by forest are the major contributors of landslide hazard in the study area. The weight of evidence model was validated by using area under curve method. The success rate curve showed the accuracy of 73.16%. It can be concluded that weight of evidence model is suitable model for landslide susceptibility analysis and the area is highly susceptible to landslide occurrence.

Highlights

Landslides are common phenomenon among the natural hazards that occur regularly in Nepal
It can be concluded that weight of evidence model is suitable model for landslide susceptibility analysis and the area is highly susceptible to landslide occurrence
The susceptibility is divided into five different classes. 30.11 km2 areas are covered by highly susceptible class (Table 3) and the area of medium susceptible class is 24.21 km2

Summary

Introduction

Landslides are common phenomenon among the natural hazards that occur regularly in Nepal. Landslide claims many human lives every year and causes. Based on a reconnaissance study, Laban (1979) estimated that at least 75 percent of all landslides in Nepal were natural. In the present situation, landslides can be induced by either natural or human factors, or both. Some natural factors that contribute to landslides are high relief or steep slopes, unstable geology, and concentrated rainfall. Human factors can be deforestation, improper land use and construction, and agricultural activities on hill slopes. Landslides often give rise to debris flows. A debris flow has enormous energy which causes widespread damage to physical structures like bridges and hydroelectric power stations on its way downstream. Potential sites that are prone to landslide should, be identified to reduce the damage caused by disaster

Objectives

Methods

Results

Conclusion