The Three Gorges Project has changed the relationship between the Yangtze River and Dongting Lake. This has caused problems for flood control and ecosystems. By studying the water flow and sediment movement, researchers found that the Songzi Outlet is best for maintaining the connection between the river and lake. To keep the river-lake relationship strong, the Songzi River channel needs to be dredged and improved. This will help restore the flow diversion to levels seen in the 1950s or 1960s.