XIA Jun, CHEN Jin, SHE Dunxian

Since July 2022, the Yangtze River Basin (YRB) has been hit by the most severe drought since 1961, which has attracted widespread public attention. Based on a long series of historical data, this study analyzed the changes of the historical extreme drought and its impact in the YRB. We also investigated the causes and characteristics of the extreme drought in the YRB in 2022, and proposed the scientific drought resistance strategy and comprehensive countermeasures of extreme drought in the YRB. The results show that severe/extreme drought in the YRB is influenced by both global climate change and intensified human activities. In 2022, the rainfall and runoff reduced largely in most areas of YRB, which were mainly caused by the atmospheric circulation anomaly, the too short Meiyu period in summer, the few landward typhoons, and etc. From the historical drought data, we found that the occurrence probability of severe and extreme drought in the lower reaches is higher than that in the upper reaches of YRB. The remarkable feature of 2022's drought is that the area and extent of extreme high temperature are ranked first since time of the measured record, and the hydrological drought during summer is also very serious. However, the 2022's extreme drought has not caused severe impact so far due to the significant improvement of drought resistance in the YRB. In the future, the focus of drought mitigation is to scientifically understand the natural properties of drought and the causes of drought. On the basis of further improving the construction of regional water conservancy networks and water conservancy projects, efforts should also be made to improve the infrastructure for drought resistance. On the other hand, the non-engineering measures, such as early warning, forecasting and dispatching, should also be strengthened with the main purpose of reducing drought losses. The risk management system and an adaptive management system should be established for flood and drought reduction in the YRB.

Keywords: Yangtze River Basin, drought in 2022, meteorological drought, hydrological drought, drought resistance ability, drought resistance strategy