During the flood season of 2022,the Changjiang River Basin experienced an unprecedented basin-wide drought.From September to October,the runoff at Datong Station fluctuated around 11,000 m3/s.Since Septem-ber,the Changjiang River Estuary has faced severe saltwater intrusion due to typhoons,jeopardizing the water sup-ply security of Shanghai.Based on analysis of measured runoff,wind speed,and salinity data,we conclude that low runoff combined with typhoons triggered the saltwater intrusion.We employed a three-dimensional estuary and coastal numerical model to quantitatively assess the impact of emergent water supply from cascading reservoirs.The emergent water supply mitigated saltwater intrusion in the Changjiang River Estuary,reducing the upward distance of saline water and shifting the 0.45 psu isohaline towards downstream by 17 km in the South Branch-North Channel section.This action reduced the salinity of reservoir water intake and extended the water intake window for the Qing-caosha Reservoir by approximately 6 hours.However,two cold fronts in October weakened the effectiveness of the water supply to some extent.To enhance the reliability of the water supply,it is crucial to strengthen comprehensive monitoring of hydrology,tides,and meteorology in the estuarine area,thereby ensuring the safety of freshwater uti-lization in Shanghai.
关键词
盐水入侵/水库调度/淡水资源/压咸效果/三峡水库/长江河口
Key words
saltwater intrusion/reservoir operation/freshwater resources/saline-reducing effect/Three Gorges Res-ervoir/Changjiang River estuary
维普
万方数据