Ice-related flooding in the lower Yellow River driven by atmospheric teleconnections over the past 160 years.

Abstract

Ice-jam floods are a unique yet understudied hydrological hazard, occurring in cold-region rivers when upstream thawing and downstream freezing create ice blockages. Despite their severe impacts, their atmospheric drivers and future trends remain unclear. Using a 160-year documentary record, historical reanalysis datasets, and statistical modeling, we examine the climatic and hydrological controls of ice-jam floods in the lower Yellow River, one of the world's most flood-prone rivers. Our findings show that ice-jam floods are strongly influenced by large-scale atmospheric teleconnections, including the Arctic Oscillation, Siberian High, and Ural Blocking, which regulate regional thermal contrasts and cold-air intrusions. Over the past century, ice-jam flood frequency has declined, with hot spots shifting toward the river estuary due to weakening upstream-to-downstream temperature gradients under climate warming. Projections using bias-corrected CMIP6 multimodel ensemble indicate a continued decline in ice-jam flood occurrences by 2100. Our study bridges historical and future perspectives, emphasizing the need for adaptive flood management as climate change shifts hydrological risks worldwide.