A Landslide Susceptibility Assessment Method Based on GIS Technology and an AHP-Weighted Information Content Method: A Case Study of Southern Anhui, China

Handong He,Lei Zhu,Qun Sun,Di Hu,Yanrong Liu

doi:10.3390/ijgi8060266

Abstract

Based on geographic information system (GIS) technology in conjunction with two methods for assessing landslide susceptibility (LS)—namely, a method using experts’ knowledge and experience, and a mathematical/statistical method—the LS of southern Anhui, China is assessed using an analytic hierarchy process (AHP) via an AHP-weighted information content method. Landslide-affecting factors are categorized into three main types and 10 subtypes. The values of spatial characteristics of the landslide-affecting factors are obtained using GIS technology. The AHP method is then employed to compare the importance and weights of landslide-affecting factors. The information content method is used to convert the measured values of the landslide-affecting factors in the study area to data reflecting regional stability. The closeness of the relationships between the classification levels of each landslide-affecting factor and landslide occurrence are calculated. The LS of the study area is assessed using the proposed method. The LS assessment shows that high LS, relatively high LS, moderate LS, relatively low LS and low LS regions account for 21.3%, 20.6%, 20.1%, 11.7% and 26.3% of the study area, respectively. Finally, the accuracy of the LS assessment results is analyzed using two methods: the assessment, including an analysis of random landslide sites for the validating models; and the area below a receiver operating characteristic (ROC) curve of area under curve (AUC) value. The results show that the proportion of landslide sites in the regions of each LS level determined using the AHP-weighted information content method increases as the LS level increases, and that the accuracies of the AHP-weighted information content method were 8.1% and 5.7% higher than those of the AHP method and information content method, respectively.

Highlights

In geomorphology, a “landslide” is the movement of a mass of rock, debris or earth down a slope under the influence of gravity [1,2,3]
This study presents an landslide susceptibility (LS) assessment method based on geographic information system (GIS) technology combined with an analytic hierarchy process (AHP)-weighted information content method
Based on the landslide susceptibility assessment map for southern Anhui (Figure 4), the proportions of regions of southern Anhui with various LS levels can be determined using the GIS-based spatial statistical function, the results of which are as follows: high LS regions account for 21.3%; relatively high LS regions account for 20.6%; moderate LS regions account for 20.1%; relatively low LS regions account for 11.7%; and low LS regions account for 26.3%

Summary

Introduction

A “landslide” is the movement of a mass of rock, debris or earth down a slope under the influence of gravity [1,2,3]. To study landslides using geographic information system (GIS), it is first necessary to identify landslides based on their characteristics as deep-seated, including main scarps, debris, mounds and hollows, or shallow landslides. Susceptibility assessments are the basis [12,13,14] for hazard and risk assessments. Susceptibility refers to the spatial possibility of occurrence of landslides of a specific type and volume. Hazard assessments determine the possibility of occurrence of a specific landslide in a given region within a certain period of time. A risk assessment adds relevant information from the relevant disaster-affected bodies, including their temporal and spatial probabilities, vulnerability and numbers (casualties and economic losses). A landslide susceptibility (LS) assessment of a given area is the basis for a landslide assessment of the area

Methods

Results

Discussion

Conclusion