Beijiang River, known as Qinshui 1 in ancient times, is one of the main streams of the Pearl River system. Originated in damao mountain, Shijie, Xinfeng County, Jiangxi Province, the mainstream flows through Nanxiong County, Shixing County, Qujiang County, Shaoguan City, yingde city, Qingyuan City to Sixianjiao, Sanshui County, connects with Xijiang River, flows into the Pearl River Delta, and flows out of the Pearl River Estuary at Xiaohushan Island, huangge town, Panyu District. The main stream is 573 kilometers long, with an average gradient of 0.7‰, and the catchment area is 52,068 square kilometers, accounting for 10.3% of the total area of the Pearl River Basin. Part of the basin spans Hunan and Jiangxi provinces. The average annual runoff of Beijiang River is 56.5438+0 billion cubic meters, and the runoff depth is 65.438+0.09 1.8 mm. The main stream is called Zhenjiang (also called Zhen water) above Shaoguan City, and Beijiang River is only called below Shaoguan. The first-class tributaries with a basin area exceeding 1 000 square kilometers include Mojiang, Jinjiang, Wujiang, Nanshui, Jiang Ge, Lianjiang, Huanjiang, Binjiang and Suijiang. 23 is the second largest river system in the Pearl River Basin and one of the most important rivers in Guangdong.