The researchers studied the changes in water flow and sediment in the Yangtze River from 1950 to 2013. They found that runoff and sediment load decreased at some stations, especially after the Three Gorges Dam was built. The dam also caused erosion in the riverbed. Sediment flow from Dongting Lake decreased, while Poyang Lake showed a slight increase. Human activities like dam construction and deforestation have significantly impacted the river's ecosystem.