What is the general situation of Dongjiang?

Dongjiang River, called Huangshui River, Jiang Xun River and Longchuan River in ancient times, is one of the main rivers in the Pearl River system. Originated in Yajiboshan, Xunwu County, Jiangxi Province, the source river is Santong River. It flows southwest through Longchuan County, Dongyuan County, Zijin County, Huicheng District and Boluo County of Guangdong Province to Shilong Town of Dongguan City, enters the Pearl River Delta, and joins the Lion Ocean in the southeast of William, Yudong Cave in Zengcheng City. The catchment area is 35,340 square kilometers, the river is 562 kilometers long, and the average annual runoff is 25.7 billion cubic meters. The main stream is called Xunwu water above Heheba in Longchuan County, and it is called Dongjiang after it joins Beiling water. There are Xinfengjiang Reservoir, Fengshuba Reservoir and Shen Dong Water Supply Project. The first-class tributaries with a basin area exceeding 1 000 square kilometers include Beilingshui, Lianjiang, Xinfengjiang, Qiuxiangjiang, Gongzhuangshui, Xizhijiang and Shima River. Dongjiang River, called Huangshui River, Jiang Xun River and Longchuan River in ancient times, is one of the main rivers in the Pearl River system. Originated in Yajipo, Xunwu County, Jiangxi Province, the source river is Santong River (once said, it originated in Zhang Jilong Mountain at the junction of Anyuan County and Xunwu County, Jiangxi Province, and the source river is Dingnan River (also known as Jiuqu River). Here, the stone wall next to the "First Waterfall of Dongjiang River" is engraved with Premier Zhou Enlai's personal inscription "Be sure to protect the source water of Dongjiang River". In June, 2004, the source of Dongjiang was determined as "Yajibo in Xunwu County" by the scientific investigation organized by Jiangxi Science and Technology Department. It flows southwest through Longchuan County, Heyuan City, Zijin County, Huicheng District and Boluo County of Guangdong Province to Shilong Town of Dongguan City, enters the Pearl River Delta, and joins the Lion Ocean in the southeast of Yudong William in Zengcheng City. The basin covers an area of 35,340 square kilometers, accounting for 5.96% of the total area of the Pearl River Basin and about 24.3% of the Pearl River Basin in Guangdong. The total length of the river is 562 kilometers, with an average gradient of 0.388‰, an average annual runoff depth of 950.4 mm and an average annual runoff of 25.7 billion cubic meters. The main stream is called Xunwu Water above Heba Village, Longchuan County, Guangdong Province, and Dongjiang River is called Dongjiang after receiving Beiling Water (Dingnan Water in Jiangxi Province), a first-class tributary at Heba Village, Longchuan County. The topography of the basin is high in the northeast and low in the southwest, with the highest elevation11kloc-0/.9 cubic meters. There are two large reservoirs in the basin, Xinfengjiang Reservoir and Fengshuba Reservoir, with a total storage capacity of15.84 billion cubic meters, accounting for 59% of the total storage capacity of 27 large reservoirs in the province. The catchment areas of the two reservoirs are 1 1050 square kilometers respectively, accounting for 40.9% of the Dongjiang River basin area. The first-class tributaries with a drainage area of 1 000 square kilometers or more include Beilingshui, Lianjiang, Xinfeng, Qiuxiang, Gongzhuang, Xizhijiang and Shima.