Assessing the Relationship between Liquefaction and Geomorphological Formations Based on Data Derived by Worldwide Case Studies

This study investigates the relationship between surficial geological units and the spatial distribution of liquefaction phenomena triggered by recent seismic events. Specifically, the earthquakes occurred in Damasi (Greece, 2021), Kahramanmaraş (Türkiye, 2023), and Christchurch (New Zealand, 2010–2011) triggered extensive liquefaction in the river valleys of the Pinios, Orontes, and Avon Rivers, respectively. Recognizing the critical role of geomorphological mapping in enhancing the accuracy of liquefaction susceptibility assessment, this study aims to statistically quantify the correlation between liquefaction manifestations and geomorphological formations. Utilizing a combination of historical, geological, and topographic maps, along with aerial photographs and satellite imagery, the evolution of each meandering fluvial system was reconstructed. Four primary geomorphological units were identified and delineated: (1) point bars, (2) abandoned meanders, (3) floodplains (<300 years) and (4) floodplains (>300 years). The density of liquefaction features (ejecta and lateral spreading) was calculated for each unit and for the overall study area. A novel methodology is proposed, where the Liquefaction Weight Factor (LWF) is determined using the formula of: LWF = ln (DenseUnit / DenseMap) in which DenseUnit and DenseMap represent the liquefaction density within each formation and the entire study area, respectively. The outcome of this study indicates that the highest LWF values correspond to point bars and abandoned meanders, verifying the strong correlation between these geomorphological formations and liquefaction occurrence. In contrast, the floodplain units exhibited lower weight factors, and consequently a lower reduced susceptibility. These findings highlight the value of detailed geomorphological analysis in improving regional liquefaction susceptibility assessments.