What is the upper reaches of Dongjiang River like?

Dongjiang originates in Yaojibo, Xunwu County, Jiangxi Province, flows southwest through Longchuan County, Heyuan City, Zijin County, Huiyang County and Boluo County of Guangdong Province to Shilong Town, Dongguan City, enters the Pearl River Delta, and joins the Lion Ocean in the southeast of the fish cave 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 above Longchuan dam is called Xunwu water, and it is called Dongjiang after it joins Beiling water. 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 and Fengshuba, 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 1,000 square kilometers include Beilingshui, Lianjiang, Xinfeng River, Qiuxiang River, Gongzhuangshui, Xizhijiang River and Shima River. The upper reaches of Dongjiang River are located above Fengshuba Reservoir, 3 kilometers west of Meishutang Village, Longchuan County, and are called Xunwu Water. The river length 138km, with an average gradient of 2.2 1‰. Located in the hilly area, the valley is V-shaped, with shallow water and narrow river. The main tributary is Beilingshui. Beilingshui (also known as Anyuan Water) is located on the right bank of Dongjiang River. It originates from Dajiji Point in Anyuan County, Jiangxi Province, flows southward into Longchuan County, Guangdong Province, and flows into Dongjiang River at Fengshuba Reservoir (formerly Heheba Village), 3 kilometers west of Meishutang Village in Longchuan. The drainage area is 2364 square kilometers, the river length is 140 kilometers, and the average gradient is 1.98‰. The main tributary is Dingnan Water.