Poyang Lake is located in the north of Jiangxi Province and the south bank of the Yangtze River. It is the largest freshwater lake in China. When the flood level is 2 1.69m, the lake length 170.0km, average width 17.3km, rainy season area 39 14km2, maximum water depth 29. 19m and average water depth 5.19m. Poyang Lake mainly relies on surface runoff and precipitation, and the main rivers entering the lake are Ganjiang, Fuhe, Xinjiang, Raohe and Xiushui. Known as Pengze in ancient times, it is connected with the waters of five rivers, namely Jiangxi, Fuzhou, Guangxi, Rao and Xiuwu, and the bottom is connected with the Yangtze River. It is wide in the south and narrow in the north, like a huge gourd tied to the waist of the Yangtze River. Its annual water inflow into the Yangtze River exceeds the total flow of the Yellow River, Huaihe River and Haihe River, and it is the regulator of the Yangtze River water flow.

After impoundment, it flows into the Yangtze River, the largest river in China, and the annual water flow into the Yangtze River exceeds the sum of the water flows of the Yellow River, Huaihe River and Haihe River. This is a seasonality and throughput lake. The water system area of Poyang Lake is162,200 km2, accounting for 97% of the basin area of Jiangxi Province and 9% of the basin area of the Yangtze River. Its annual runoff is152.5 billion cubic meters, accounting for 16.3% of the annual runoff in the Yangtze River Basin.