Y angtze River Basin in Brief
The Y angtze 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
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The mainstrean of the Y angtze 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 P lateau, passing through China’s 11 provinces (or autonomous regions or the municipalities directly under the Central Government), including Qinghai, Tibet, Y unnan, 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 Y angtze basin involves a catchment area of 1.8 million km2, accounting for 18.75% of China’s tot al.
The Y angtze 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 Y ushu, and finally it is named the Y angtze River after joined by Minjiang River at Y ibin in Sichuang Province. For the Y angtze River, the reach between Y ibin 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 Y angtze River Basin posss 8 main tributaries with a catchment area of more than 80000 km2, including Y along River, Minjiang River, Jialing River, Wujiang River, Y uanjiang 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 Y angtze basin, of which Poyang Lake is the biggest in China (Table 2).
The ction upstream of Y ichang is known as the upper reaches with a length of 4500 km and a catchment area of 1,000,000 km2. From Y ichang to Hukou, the river enters into the middle reach with a length of 950 km and a catchment area of 680,000 km2. The ction 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 Y angtze runs through Alps-Ravines with steep slope and rapid flow except in a small ction of the source area, the total water head reaches 5100 m, accounting for 95% of the total of the River.
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The reach from the mouth of Batang River to Y ibin 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 Y ichang, 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 Y angtze River basin, it is high in west and low in east through China’s three major topographic cascades. The first cascade is compod of the Southern Qinghai Plateau, the Western Sichuan Plateau and the Hengduan mountainous region, with an average elevation of 3500~5000 m. The cond cascade is compod of Qinba mountainous region, Sichuan Basin, Y unnan-Guizhou Plateau and the mountainous regions of Hubei and Guizhou provinces, with an average elevation of 500~2000m. The third cascade is compod of Huaiyang mountainous region, t
he hills in the southern area and the Middle-Lower Y angtze Plain, with an average elevation of less than 500m. The terrain of the Y angtze 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 Y angtze 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 Y angtze 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 Y angtze 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
原创诗词
The Y angtze basin is rich in aquatic biodiversity, according to investigation, there are more than 370 fish species, of which one third are endemic species, the output of the main c ommercial fish –―Four family fishes‖ (Chine carps) account for 60% of the nation’s total. The Y angtze is also the home of some rare species, of which Chine river dolphin ( Baiji ) ,Chine paddlefish, Chine sturgeon and Y angtze sturgeon are in Class I , while Chine finless porpoi and Chine sucker are in Class II on the list of the nation protected species. . In recent years, as a result of increasing human activity, some species are in danger of extinction，the biodiversity has been showing a declining trend in the basin.
The mean annual content of suspended diment in the Y angtze water is less than 1kg/m3, however, due to the huge runoff, annually more than 486 Mt of diments are discharged into the a. In recent years, due to the effect of rervoir formation and soil & water conrvation measures implemented the SS content in the Y angtze water and diment discharge have been reduced significantly (e Table 3).
Table 3 Sediment in the Y angtze River
Hydrological Station Catchment
area霸气的群名称
（km2）
Sediment content (kg/m3) Annual average阜阳特色
diment discharge (Mt) 1956~1979 1980~2000 1956~1979 1980~2000
Yichang 1005501 1.17 1.10 514 486
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Hankou 1488036 0.62 0.52 426 375
Datong 1705383 0.55 0.48 470.17 430.42
2 Natural Disasters and Ecology and Environment
The Y angtze Basin is one of the most rious regions suffering flood disasters in China, where rainfalls are concentrated and floods and water-loggings often occur in flood ason, especially in the Middle and Lower Y angtze Plain. According to historical records, in last 2000 years from Western Han Dynasty to the late Qing Dynasty（206 B.C. to 1911 A.C.）, there were 214 flood
disasters, once every 10 years on average. In 20th century, the floods in 1931, 1935, 1954 and 1998 were the heaviest ones causing vere damage and loss. Moreover, droughts often occur in Y unnan-Guizhou Plateau, Sichuan valley and hilly areas i n the mi ddl e and l ower basi n.
失恋看的电影Due to the huge quantity and good quality, the Y angtze River has been an excellent water source for industrial, agricultural and domestic us, besides, it is also excellent habitats for aquatic biota. However, along with the population increa and rapid economic growth, the amount of wage and wastewaters discharged into the Y angtze has been increasing significantly in recent decades, in 2005 the wage drainage reached 29.64billion tons, of which 20.4billion tons are industrial wastewaters and 9.24 billion tons are domestic wages, as a result, water quality of the Y angtze has been deteriorating. The main pollutants are NH3-N and organic matters. In general, the water quality in the tributaries is wor than that in the main stream, the water quality in lower reaches is wor than that in the upper reaches, the water quality near riversides is wor than that in the middle stream, and the water quality in city reaches is wor than that in non-city reaches. The eutrophication of lakes in the basin is very common and Taihu Lake, Dian Lake and Chaohu Lake have been listed by the nation as the key lakes to be harnesd.
According to water quality asssment carried out in 2005 on the 30000 km of river reaches in the Y
angtze basin, the ratio of polluted river ctions reached 27.4%, 8.5% increa compared with that in 1998, and the ratio of polluted water body in provincial boundary exceeded 40%. According to an investigation in 2002, the total near-shore pollution belt length in 21 main city ctions reached 655 km, 90 km increa compared with that in 1992. For the 2608 water function zones in the basin, about 25% of them the pollution load has exceeded the permissible assimilative capacity.
The upper region of the Y angtze River is one of the regions suffering the most rious soil and water loss. According to the investigation in 1990, the erosion area reached 62.2×104km2, accounting for 34.6% of the basin’s total, which are mainly distributed in the upper and middle basin, especially in the upper reaches.
The Y angtze Basin is the main areas infected by schistosomiasis epidemic in China, although it was once effectively controlled in 1960’s, however, it has come back again in recent years. According to the statistics in 2003, it prevailed in 110 counties in the basin including Y unnan, Sichuan, Hubei, Hunan, Jiangxi, Anhui and Jiangsu provinces with the snail distribution area of 3.79billion m2.
3 Socio-economical Status
The Y angtze River Basin involves 19 provinces (autonomous regions and municipalities), among th
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em, 95% of the territory of Sichuan, Chongqing, Hubei, Hunan, Jiangxi and Shanghai are within the scope of the basin; and 65% for Guizhou, 35~50% for Shanxi, Anhui and Jiangsu; while for the rest provinces, less than 35% of the territory are within the basin scope.
There are more than 30 nationalities living in the Y angtze Basin, among them, the Han nationality accounts for more than 95%; the rests are Hui, Miao, Tibetan, Zhuang, Dong, Y i, Tujia and Naxi, etc. mainly inhabiting in the upper Yangtze basin. In 2005, the inhabitants living in the basin reached 429 million, accounting for 32.8% of the China’s total, with a mean density of 238 persons/ km2, 1.8 times of nation’s average.
The Y angtze Basin is mild in climate and fertile in land, and also rich in mineral resources, of which the rerve of 30 minerals exceeds 50% of China’s total;the rerve of Ti V Hg and P account for above 80~90%, and Fe, Pb, Zn, Mo, Au and Ag,etc. account for more than 30% of the nation’s total rerve.
The Y angtze Basin is famous in tourism resources with many unique natural landscapes and cultural relics, including the famous Y angtze Three Gorges, Tiger Leaping Gorge, Huangshan Mountain, Lushan Mountain, Jiuhua Mountain, Emei Mountain, Jiuzhaigou and Zhangjiajie, etc. Sinc
e Tang Dynasty, the Y angtze Basin has been the economic center and the birthplace of China's modern industry. In recent years, taking Shanghai and Nanjing as the lower Y angtze center, Wuhan as the middle Y angtze center, and Chongqing, and Chengdu as the upper Y angtze center, three major economic zones have been formed in the Y angtze basin. In 2005, the GDP of the Y angtze Basin reached5996.7 billion CNY, accounting for 32.8% of nation’s total. However, prently the economic development in the basin is imbalanced, generally developed in the Delta region and relatively backward in the upper basin.
4 Harnessing and Development
Since 1950’s, great achievements have been made in the development and protection of the Y angtze River. Since 1950’s, the Comprehensive Utilization Planning of the Y angtze Basin was compiled by CWRC and approved by the State Council in 1990. 3600 km of embankment along the mainstream (such as Jingjiang Grand Dike) and more than 60,000 km long branch levees in the middle and lower basins have been built and strengthened; the flood diversion and detention areas, such as Jingjiang Flood Detention Area and Dujiatai works, have been constructed, with the flood storage capacity of more than 50 billion m3. After the 1998 heavy floods, the Chine government invested a huge amount of money to reinforce the trunk dykes along the Y angtze mainstream. Curre
ntly, there are about 48,000 rervoirs of different scales in the basin with a total storage capacity of about 160 billion m3. In addition, the effective irrigation has reached 62% of the farmland area in the basin. Up to now, more than 2,440 hydropower stations of various scales have been constructed or under construction in the basin, with a total installed capacity of 69,730 MW and an annual power output of 292.5 TWh, of which 9 stations have a installed capacity exceeding 1000 MW. The Three Gorges Project (TGP) has tremendous benefits in flood control, after completion, it will greatly improve the flood control situations in the middle Yangtze in joint operation with dikes, flood diversion and detention areas and rervoirs. The South-to-North Water Diversion Project (East and Middle routes) is a strategic water project to easy the water shortage in north China, which have been started in 2004 and 2005 and the 1st pha of the project will be completed in 2010. In the Y angtze estuary, the projects to comprehensively harness the estuary and the navigation channel have been underway. Since the
