长江流域简介(英文)

Yangtze River Basin in Brief The Yangtze River, traversing the West, Middle and East China, is the largest river in the country and the third largest in the world. It occupies the most important strategic position for allocation of water resources to support eco-social sustainable development in China. 1. Natural Status The mainstrean of the Yangtze River originated from the southwestern side of the snow-Capped Mountain of the Geladandong—the main peak of Tanggula Mountains on the Qinghai and Tibet Plateau, passing through China’s 11 provinces (or autonomous regions or the municipalities directly under the Central Government), including Qinghai, Tibet, Yunnan, Sichuan, Chongqing, Hubei, Hunan, Jiangxi, Anhui and Jiangsu, and finally enters into the East China Sea in Shanghai, with a total length of more than 6300 km and total fall head of more than 5400 m. Its tributaries extended 8 provinces and autonomous regions including Gansu, Sanxi, Henan, Guizhou, Guangdong, Guangxi, Fujian and Zhejiang. The Yangtze basin involves a catchment area of 1.8 million km2, accounting for 18.75% of China’s total. The Yangtze River has its source stream from the Tuotuo River, after converging with the south source Dangqu River it is called Tongtian River, and then it is named Jinsha River after merging with the north source Chumar River and joined by Batang River at Yushu, and finally it is named the Yangtze River after joined by Minjiang River at Yibin in Sichuang Province. For the Yangtze River, the reach between Yibin and Yichang is called Chuanjiang River; the reach between Zhicheng and Chenglingji is called Jingjiang River. With a large water system and numerous tributaries and lakes, the Yangtze River Basin possesses 8 main tributaries with a catchment area of more than 80000 km2, including Yalong River, Minjiang River, Jialing River, Wujiang River, Yuanjiang River, Xiangjiang River, Hanjiang River and Ganjiang River, among them Jialing River is the biggest in terms of area, Minjiang River is the largest in terms of discharge, and Hanjiang River is the longest (Table 1). In addition, there are 4 large fresh water lakes, namely Dongting Lake, Poyang Lake, Chaohu Lake and Taihu Lake in the Yangtze basin, of which Poyang Lake is the biggest in China (Table 2). Table 1    The main tributaries of the Yangtze River Name of Tributary Catchment Area （104 km2） Mean Annual Discharge （m3/s） Length （km） Yalong River 12.8 1914 1535 Minjiang River 13.3 2850 735 Jialing River 16.0 2120 1120 Wujiang River 8.8 1690 1037 Xiangjiang River 9.34 2070 856 Yuanjiang River 8.8 2070 1033 Hanjiang River 15.9 1640 1577 Ganjiang River 8.35 2130 819         Table 2    Main Lakes in the Yangtze Basin Name of Lake Province Elevation (Wusong Datum/m） Area （km2） Volume （billion m3） Average Depth （m） Poyang Lake Jiangxi 22 3750 29.57 7.41 Dongting Lake Hunan 33.5 2625 16.7 6.37 Taihu Lake Jiangsu 3.1 2338 4.43 2.08 Chaohu Lake Anhui 10 770 2.07 6.17             The section upstream of Yichang is known as the upper reaches with a length of 4500 km and a catchment area of 1,000,000 km2. From Yichang to Hukou, the river enters into the middle reach with a length of 950 km and a catchment area of 680,000 km2. The section downstream from Hukou to the estuary is the lower reach with a length of 930 km and a catchment area of 120,000 km2. The upper Yangtze runs through Alps-Ravines with steep slope and rapid flow except in a small section of the source area, the total water head reaches 5100 m, accounting for 95% of the total of the River. The reach from the mouth of Batang River to Yibin is 2300m long with an average slope of 1.37‰; the Tiger-leaping Gorge in downstream of Shigu of Jinsha River is a world famous peculiar gorge, with a length of 17 km, a water head of 170 m, a gorge depth of 2500~3000 m, and a river width of only 30 m in the narrowest part. The reach from Yibin to Chongqing is 370 km long with an average slope of 0.27‰; the reach between Chongqing and Yichang is 660 km long with an average slope of 0.18‰, of which the 192 km reach from Fengjie to Yichang is the famous "Three Gorges" (Qutang Gorge, Wuxia Gorge and Xiling Gorge). Downstream from Yichang, the river flows into the middle-lower alluvial plain with flat topography on both banks, and with an average slope of 0.03‰ between Yichang and Hukou and 0.007‰ for the reach from Hukou to the estuary, of which the part of about 600 km long downstream from Datong in Anhui province belongs to tide influenced reach. For the terrain of the Yangtze River basin, it is high in west and low in east through China’s three major topographic cascades. The first cascade is composed of the Southern Qinghai Plateau, the Western Sichuan Plateau and the Hengduan mountainous region, with an average elevation of 3500~5000 m. The second cascade is composed of Qinba mountainous region, Sichuan Basin, Yunnan-Guizhou Plateau and the mountainous regions of Hubei and Guizhou provinces, with an average elevation of 500~2000m. The third cascade is composed of Huaiyang mountainous region, the hills in the southern area and the Middle-Lower Yangtze Plain, with an average elevation of less than 500m. The terrain of the Yangtze River Basin is complicated, consisting of 84.7% of mountain and hilly land, 11.3% of plain region, and 4% of water surface. Most of the Yangtze River Basin is situated in the middle-latitude subtropical region with monsoon climate and abundant rainfall. The mean annual precipitation is about 1100 mm, the total volume of water resources is 996 billion m3 accounting for 35.1% of the total in China.. The basin has a theoretical hydropower potential of 277810MW (2433.6 TWh/year), accounting for about 40% of nation’s total; a technically feasible potential of 256270 MW (1187.9 TWh/year), and an economically feasible potential of 228320 MW (1049.8 TWh/year), accounting for 48% and 60% of the nation’s total respectively. 90% of the hydro-energy resources in the Yangtze Basin are concentrated in the upper basin and will mainly be exploited by building large-scale hydropower stations (73% of the total), including 52 large hydropower stations with an installed capacity of more than 1000 MW each, and the largest one ---the Three Gorges Hydropower Station reaches 22400 MW (90 TWh/year). There are 3600 navigable channels in the Yangtze basin, mainly distributed in the middle and lower basin with the inland waterway mileage of 66386 km, accounting for 49.1% of nation’s total. After completion of the Three Gorges Project (TGP), 10000-ton towboats will be able to pass through right up to Chongqing port