The role of lakes in the middle reaches of the Yangtze River

There are two lakes in the Yangtze River: Dongting Lake in Hunan and Poyang Lake in Jiangxi. They not only have the functions of shipping, fish farming, irrigation, aquaculture and domestic water, but also play a natural storage role. Store water in flood season, intercept flood peak and reduce the threat of mainstream flood; Drainage in dry season is beneficial to the main stream to play a better role.