Study on ecological response and coordinated regulation of the hydrological system in the middle reaches of the Yangtze River to the operation of the Three Gorges Reservoir

Abstract

The Three Gorges Dam's operation has profoundly influenced hydrological conditions in the middle Yangtze River basin. Using data from extreme droughts spanning 2010—2020 and 2022, precipitation, temperature, water level trends, and drought responses was studied through SPI(Seasonal Precipitation Index) analysis and regression method. Key findings include:(1)Precipitation showed marginal increases during 2010—2020 with stable temperatures, while the Lishui River 16.5~17.5 ℃ experienced water level 23.5~26.8 m fluctuations.(2)SPI values ranged between-0.5 to 1.0, indicating normal conditions(55%) and mild drought(30%), with annual patterns showing initial aridity followed by recovery.(3)Water levels demonstrated positive correlations with precipitation and runoff but negative correlations with temperature.(4)June 2022 saw a sudden drop from 27.3 m to 28.3 m, followed by moderate to severe drought from January to June. Notably, April, May, and July water levels showed significant SPI correlation, reflecting summer drought characteristics. The research provides critical insights for agricultural disaster prevention and integrated Three Gorges-lake basin management strategies.

Keywords

Dongting Lake basin / hydrological response / drought situation / Three Gorges Reservoir dispatch