Understanding floods and droughts in the Yangtze River Basin: a historical perspective (1470-2022)

The Yangtze River basin plays a crucial role in China's economy, and the impacts of drought and flood in the basin are becoming more uncertain due to climate change. Thus, a study was conducted to analyse the flood-drought rating sequence for the Yangtze River basin in 1470-2022. The frequency of flood and drought occurrences during the flood season followed a normal distribution. Extreme drought and flood accounted for 2-4% of occurrences. Partial and extreme floods increased notably in the 19th and 20th centuries, while droughts became more frequent after the 20th century. Furthermore, the Three Gorges Reservoir area's storage capacity did not significantly impact flood season precipitation in the upper reaches of the Yangtze River and the reservoir area. This comprehensive study serves to uncover evolutionary patterns and trends of drought and flood, providing valuable insights for effectively managing water resources in the basin.