Presenter
Prof. Jijun Xu, Changjiang River Scientific Research Institute
Co-author(s)
Dr. Zhe Yuan, Changjiang River Scientific Research Institute
Sub-theme
3. Building Resilience for Disaster Prevention and Mitigation
Topic
3-1. Prevention and mitigation of extreme weather induced water-related disasters
Body
The Yangtze River basin (YRB) suffered a prolonged and widespread drought in the summer of 2022 as a result of air circulation abnormalities. This paper analyzed the drought disaster events that occurred in the YRB over the previous 15 years and characteristics of the drought event in 2022. In addition, situation of the construction of the drought mitigation system in the YRB and its effectiveness in the response to the 2022 drought were introduced. Finally, the paper proposed general response concepts and technical requirements for drought mitigation in the new era. Specifically, these include: (1) The YRB had widespread and frequent drought disasters during 2006 to 2020, with Dongting Lake, Poyang Lake, and the southwest region experiencing the highest occurrence. The extreme low precipitation and continuing elevated temperatures in 2022 caused a drought that lasted for a long time, affected a wide range of areas, and resulted in a large degree of disaster, which caused a total drought area of about 2.852×104 km2 of cropland, and 4.73 ×106 people and 0.71×106 large livestock had difficulties in water supply due to drought, and the water body of Poyang Lake and Dongting Lake decreased by 2450.96 km2 and 1504.62 km2 respectively, compared with the same period, the water body decreased by nearly 3/4; however, the majority of regions did not experience serious agricultural drought, serious water supply safety accidents, or other economic and social losses, realizing "No serious disaster in extreme drought," which is made possible by the more comprehensive monitoring systems. (2) The drought mitigation response in the YRB in the new era should be: to optimize the spatial layout of the country as an entry point to avoid the risk of drought disasters at the source; to realize the process of drought disaster prevention and control through three-dimensional storage in space and peak storage and replenishment in time; to optimize the operation and scheduling of water conservancy projects as a means to realize flood and drought control. (3) The requirements for drought mitigation in the YRB in the new era include: drought assessment and extrapolation forecasting methods suitable for complex conditions, multi-scale drought risk assessment based on disaster system theory, integrated drought risk response model with risk avoidance at source and prevention in process, and public finance integration disaster risk financial mechanism and other aspects.