Yellow River flooding during the past two millennia from historical documents

摘要

The Yellow River has caused suffering to people with its devastating floods throughout human history. Understanding the occurrence of Yellow River floods and their relationship with climate change is crucial for sustainable water governance in North China. Here we synthesize historical and climatic records in the Yellow River basin to investigate their relationship during the past two millennia. Based on historical archives of river floods and levee breaches, we developed a decadally resolved Yellow River flooding frequency record from 221 BCE to 1949 CE, which provides a rare chance to perceive the river's long-term flood dynamics. As revealed, the Yellow River flooding can be divided into two distinct stages: an early stage of low-frequency floods from the 220s BCE to the 890s CE; and a late stage of high-frequency floods during the 900s-1940s CE. A substantial increase in flooding frequency around the 10th century fell within the transition period into the Medieval Climate Anomaly (MCA), during which the Yellow River basin featured warm and wet climate conditions. Coincidentally, human management of the Yellow River intensified as a response to more severe and frequent floods. The intense river management persisted thereafter and resulted in the super-elevation of the riverbed, which made the river more prone to flooding. Consequently, the Yellow River flooding frequency remained high even after entering the Little Ice Age, during which the river basin featured cool temperature and reduced precipitation. Our study suggests that the dramatic transition from a previous cool, dry into a warm, wet climate during the MCA period triggered intense human management of river channels and the establishment of the flood-prone nature of the Yellow River.