Risk Assessment of Earthquake-Triggered Geohazards Surrounding Wenchuan, China

The great 2008 Wenchuan earthquake in China was a painful disaster. Accordingly, the management and mitigation of the risk of future earthquake-triggered geohazards remain a critical responsibility of local authorities. This case study assesses the risk of earthquake-triggered geohazards surrounding Wenchuan County using the analytical hierarchical process (AHP) and the trapezoidal fuzzy AHP (FAHP). The assessment results show that the regions with high-risk and very high-risk levels are distributed in the belt along the Longmenshan fault zone. Moreover, the percentages of high and very high-risk levels obtained from the trapezoidal FAHP are higher than those obtained from the original AHP. This comparison reveals that the trapezoidal FAHP provides a more reasonable assessment than the AHP. Further, the trapezoidal FAHP can capture the regions with high-risk and very high-risk levels. The results from the trapezoidal FAHP provide four choices that stakeholders can use to make decisions, which mitigates the biases that exist in the original AHP.