Enhancing Liquefaction Hazard Forecasting on Regional Scale

Abstract

Soil liquefaction is an earthquake-induced phenomenon that is frequently reported on alluvial plains and coastal areas. Though the fact that liquefaction is considered as a low-level hazard compared to other relevant coseismic phenomena, can cause severe damage to lifelines, critical facilities and other structures constructed upon loose and saturated Quaternary deposits. Today, two approaches are followed for assessing liquefaction susceptibility and hazard of a site: the local scale and the regional one. The former is based on in-situ tests conducted on the selected site, while the latter is based on qualitative criteria combined by considering post-earthquake reports and the spatial distribution of geological features. This study investigated the correlation between geological/geomorphological features and the density of liquefaction occurrences aiming to propose a new quantitative classification of liquefaction potential of geomorphological features. As an outcome, it was clearly shown that the deposits of the inner part of meanders, characterized as point bar formations, are characterized by the highest weight values followed by the areas mapped as abandoned river channels.