A Method for Rapidly Assessing Landslide Hazard——Taking the Landslide in Yongxing Town, Mingshan Area as an Example

Abstract

This study selects a combination of three evaluation factors, considering seven factors: lithology, slope, aspect, elevation, distance from faults, distance from water systems, and rainfall. The Analytic Hierarchy Process (AHP) is combined with the information value method (IV), certainty factor method (CF), and frequency ratio method (FR) from previous studies to assess the landslide hazard in Yongxing Town, Mingshan Area, Ya'an City, Sichuan Province. The AHP-IV and AHP-FR methods assess the study area as a moderately hazardous zone, while the AHP-CF method assesses it as a slightly hazardous zone. Affected by the strong 2013 Lushan earthquake, the landslide in the study area caused permanent damage. Field investigation results show that the landslide hazard in the study area is moderate, and the AHP-IV and AHP-FR methods are more consistent with the actual field results. The AHP-CF method, due to not considering the water system factor and having certain errors in its discrimination method, leans towards a safer assessment. The results of the three evaluation methods are somewhat consistent, and this paper proposes a method for rapidly assessing landslide hazard based on previous research results.

Keywords: Hazard assessment, Analytic Hierarchy Process, Information value method, Certainty factor method, Frequency ratio method, Peak ground acceleration