The water diversion quantity from four outlets of the Jingjiang River is decreasing over time, which affects the connection between the Yangtze River and Dongting Lake. This decrease is caused by factors like sediment buildup, reduced river channel area, and changes in the Yangtze River's flow. As a result, the relationship between the river and the lake is changing rapidly, impacting flood control systems and overall river management. Further research is needed to understand these changes and plan for the future regulation of the river and lake.