A documentary record of earthquake-induced floods and risk assessment in the lower Yellow River during the past 700 years

Abstract

Flooding has long been a significant concern in the lower Yellow River. While most paleoflood studies have mainly focused on rainstorm-induced floods, our understanding of earthquake-induced floods (EIFs) remains limited. In this study, we compile documentary records of EIF events in the lower Yellow River basin, utilize kernel density estimation (KDE) to analyze their temporal and spatial distribution, and integrate analytical hierarchy process (AHP) outcomes to assess associated risks. The results show that EIFs in the alluvial plain of the lower Yellow River are mainly concentrated along river channels controlled by active fault zones, with a declining overall occurrence frequency over time. The occurrence of EIFs is largely determined by earthquake magnitude and influenced by a combination of factors, including earthquake frequency, the proximity of the river to the epicenter, and population size or density. However, since the mid-19th century (late Qing Dynasty), human activities have increasingly contributed to the risk profile of EIFs. Looking forward, high-risk areas for EIF disasters are likely to remain concentrated in the Bohai strong earthquake tectonic belt, the Tanlu fault zone, and several other fault intersections. Our results provide valuable guidance for disaster risk reduction, urban planning, and sustainable development in this flood-prone area.