After the Three Gorges Project was completed, the Yangtze River downstream will experience changes in water and sediment flow. This will lead to river bed scouring, affecting flood control. By using math models and observed data, researchers found that the river bed will deepen, causing lower water levels. The Jingjiang river reach will see a scour depth of 2.0-5.3 meters, increasing its storage capacity. The Chenglingji reach will deepen by 2.5 meters, adding storage capacity. This will reduce sediment flow into Dongting Lake, increasing its water storage. These changes will impact the river's stability and safety, requiring appropriate measures to be taken.