Why does the Yangtze River bring more sediment to Dongting Lake than the other four tributaries?

(1) Jingjiang River bends, which is called "nine-bend ileum". Part of the reach forms an aboveground river. When the Yangtze River flows through this area, it carries sediment (siltation by running water) because of its low terrain, slow water flow and poor drainage. In order to prevent floods and reinforce dams, rivers on the ground have been formed over time.

(2) Because the water volume and sediment concentration of the Yangtze River are far greater than those of the other four major water systems.

(3) When there is more precipitation in the Yangtze River basin in summer and autumn, the water level of the Yangtze River is higher than that of Dongting Lake, and the Yangtze River water flows into Dongting Lake, bringing a lot of sediment into Dongting Lake for deposition.

(4) Reclaiming land and silting around the lake, the area and volume of Dongting Lake decreased, which weakened its flood storage function and led to an increase in the frequency and intensity of flood disasters in the middle and lower reaches of the Yangtze River and Xiangjiang River Basin.