GIS-Based Integration of Subjective and Objective Weighting Methods for Regional Landslides Susceptibility Mapping

Suhua Zhou,Ligang Fang,Yunwen Nie,Guangqi Chen

doi:10.3390/su8040334

Suhua Zhou, Ligang Fang + Show 2 more

Open Access

https://doi.org/10.3390/su8040334

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Abstract

The development of landslide susceptibility maps is of great importance due to rapid urbanization. The purpose of this study is to present a method to integrate the subjective weight with objective weight for regional landslide susceptibility mapping on the geographical information system (GIS) platform. The analytical hierarchy process (AHP), which is subjective, was employed to weight predictive factors’ contribution to landslide occurrence. The frequency ratio (FR) method, which is objective, was used to derive subclasses’ frequency ratio with respect to landslides that indicate the relative importance of a subclass within each predictive factor. A case study was carried out at Tsushima Island, Japan, using a historical inventory of 534 landslides and seven predictive factors: elevation, slope, aspect, terrain roughness index (TRI), lithology, land cover and mean annual precipitation (MAP). The landslide susceptibility index (LSI) was calculated using the weighted linear combination of factors’ weights and subclasses’ weights. The study area was classified into five susceptibility zones according to the LSI. In addition, the produced susceptibility map was compared with maps generated using the conventional FR and AHP method and validated using the relative landslide index (RLI). The validation result showed that the proposed method performed better than the conventional application of the FR method and AHP method. The obtained landslide susceptibility maps could serve as a scientific basis for urban planning and landslide hazard management.

Highlights

The rapid urbanization associated with explosive population growth has brought great challenges to the environment and intensified pressures on land demand
We proposed an integrated landslide susceptibility mapping (LSM) method according to the frequency ratio (FR) and analytical hierarchy process (AHP) approach
Results from the AHP method may vary while performed by different experts and, may be subjected to subjectivity

Summary

Introduction

The rapid urbanization associated with explosive population growth has brought great challenges to the environment and intensified pressures on land demand. During the process of land resource exploitation in mountainous terrain, fragile ecosystem and complex terrain conditions make these areas more susceptible to severe environmental disasters [1]. Landslides are especially prevalent in mountainous terrains [2], which always induce serious economic, human and environmental losses throughout the world. From 1900 to 2014, landslides accounted for nearly 40% of global natural hazards according to the International Disaster Database [3] Landslide susceptibility is the likelihood of a certain region favorable to landslides on the basis of given geological and terrain conditions. Identifying the region’s susceptibility is very important to avoid landslide damage or to reduce losses caused. In the past two decades, LSM has become a very important and effective way to assess landslide disasters [4]. The results of LSM can be used for land management and landslide hazards mitigation

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Results

Conclusion