Located in the north of Jiangxi Province, Poyang Lake is the largest freshwater lake in China and the second largest lake in China. It is one of the main tributaries of the middle and lower reaches of the Yangtze River, and it is also an important water carrying, huff and puff and seasonal Lake in the Yangtze River Basin.
Poyang Lake plays a great role in regulating the water level of the Yangtze River, conserving water sources, improving the local climate and maintaining the ecological balance of the surrounding areas.
Poyang Lake connects five rivers to the Yangtze River, becoming the "catchment basin" of the whole province and the "transfer station" for the five rivers into the river. Poyang Lake is the catchment center of the basin. Only the lake mouth is connected with the Yangtze River, controlling the water throughput balance between the basin and the Yangtze River. The average runoff out of the lake for many years is 150.9 billion cubic meters. It not only receives the water from the five major rivers in the basin, but also 14 rivers with a distance of more than 30 kilometers flow into the lake around the lake area. Under certain circumstances, it also receives the backflow of the Yangtze River.
Poyang Lake water system covers an area of 620 kilometers from north to south, 490 kilometers from east to west, and a drainage area of 162225 square kilometers, equivalent to 97.2% of Jiangxi's land area of 166946 square kilometers, of which 156743 square kilometers are located in Jiangxi Province, accounting for 96.6% of the drainage area and 94% of Jiangxi's land area. The remaining 5482 square kilometers belong to Fujian, Zhejiang, Anhui, Hunan, Guangdong and other provinces, It accounts for 3.3% of the drainage area.