A New Approach Using AHP to Generate Landslide Susceptibility Maps in the Chen-Yu-Lan Watershed, Taiwan.

Thi Nguyen,Cheng-Chien Liu

doi:10.3390/s19030505

Abstract

This paper proposes a new approach of using the analytic hierarchy process (AHP), in which the AHP was combined with bivariate analysis and correlation statistics to evaluate the importance of the pairwise comparison. Instead of summarizing expert experience statistics to establish a scale, we then analyze the correlation between the properties of the related factors with the actual landslide data in the study area. In addition, correlation and dependence statistics are also used to analyze correlation coefficients of preparatory factors. The product of this research is a landslide susceptibility map (LSM) generated by five factors (slope, aspect, drainage density, lithology, and land-use) and pre-event landslides (Typhoon Kalmaegi events), and then validated by post-event landslides and new landslides occurring in during the events (Typhoon Kalmaegi and Typhoon Morakot). Validating the results by the binary classification method showed that the model has reasonable accuracy, such as 81.22% accurate interpretation for post-event landslides (Typhoon Kalmaegi), and 70.71% exact predictions for new landslides occurring during Typhoon Kalmaegi.

Highlights

Landslides are disasters which often occur in hilly or mountainous places in the rainy season.They are classified as a category of disasters triggered by hazards related to geological processes and meteorology [1,2]
According to a statistical report on disasters in the last decade (2006–2015) produced by the International Federation of Red Cross (IFRC), landslides account for 4.7% (177 events) of the total number of reported natural hazards [1]
“Natural Disaster Hotpots: A Global Risk Analysis” (2005), noted that Taiwan is a small country with an area of approximately 36,000 km2 and a population of about 23 million people, but is classified as a high-risk country for such disasters [3]

Summary

Introduction

Landslides are disasters which often occur in hilly or mountainous places in the rainy season. They are classified as a category of disasters triggered by hazards related to geological processes (earthquakes, volcanic eruptions, floods in mountainous areas) and meteorology (heavy rains, storms, or typhoons) [1,2]. “Natural Disaster Hotpots: A Global Risk Analysis” (2005), noted that Taiwan is a small country with an area of approximately 36,000 km and a population of about 23 million people, but is classified as a high-risk country for such disasters [3]. In other statistics examining countries which are at relatively high mortality risk from multiple hazards, Taiwan ranked first of the top 35, with 95.1% of its population living in areas at risk [3].

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Conclusion