The three longest river basins in China.

1. The Yangtze River is the largest river in China, also known as the Yangtze River. The length of the river is second only to the Nile and the Amazon, and the amount of water entering the sea is second only to the Amazon and Congo rivers, ranking third in the world.

River Basin Overview The Yangtze River originates from the south side of Glacier Snow Mountain, the main peak of Tanggula Mountains (see Color Map of the Source of the Yangtze River-Glacier on the Southwest Slope of Glacier Snow Mountain in Tanggula Mountains). Its main stream flows through Qinghai, Tibet, Sichuan, Yunnan, Hubei, Hunan, Jiangxi, Anhui, Jiangsu and Shanghai, and its tributaries involve Guizhou, Guangxi, Gansu, Shaanxi, Henan, Guangdong, Zhejiang and Fujian, with a total of 60. The main stream is 6300km long and the drainage area is 654.38+807,000 km. The larger tributaries are: Yalong River, Minjiang River, Jialing River, Wujiang River, Xiangjiang River, Yuanjiang River, Hanjiang River and Ganjiang River. The basin covers an area of over 80,000 kilometers. The upstream of the main stream reaches Yichang, with a length of 45 10km. Except for Sichuan basin, most of them flow through high mountains and canyons, with steep slopes and rapid flows, with a drop of 5360m, accounting for 98.9% of the total drop of the whole river. The length from Jiangyuan to Dangqu is about 360 kilometers, which is the so-called Tuotuo River. Dangqu to Yushu Batang estuary is about 820km long, which is called Tongtian River. The length from Batang estuary to Yibin is about 2300km, which is called Jinsha River. Yibin to Yichang is about 1000km long, which is called Chuanjiang. The lower reaches of the Chuanjiang River, which is 209km long from Fengjie to Nanjinguan, is the famous Three Gorges and enters the middle and lower reaches of the plain below Yichang. Yichang-Poyang Lake estuary is the middle reaches, about 940km long. Below the estuary is the downstream, which is about 850 kilometers long. The middle reaches from Zhicheng, Hubei Province to Chenglingji, the exit of Dongting Lake, are about 340 kilometers long and are called Jingjiang River. The winding river and low-lying banks are the most severe flood control situation in the Yangtze River. There are many lakes in the middle and lower reaches of the plain. The main Tongjiang lakes are Dongting Lake, Poyang Lake, Chaohu Lake and Taihu Lake.

2. The Yellow River is the second longest river in China, which is famous for its high sediment concentration and frequent floods.

Overview of the Yellow River Basin starts from Bayan Kara in the west, reaches Bohai Sea in the east, Qinling Mountains in the south and Yinshan Mountain in the north, with a basin area of 752,000 square kilometers. The Yellow River originates at the northern foot of Bayan Kara on the Qinghai-Tibet Plateau, flows through nine provinces and regions including Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shanxi, Shaanxi, Henan and Shandong, and joins the Bohai Sea in Kenli County, Shandong Province, with a total length of about 5400km. From Heyuan to Tuoketuo, Inner Mongolia, most areas above the upper reaches and Lanzhou have good vegetation coverage; There are many canyons in the main stream from Maduo to Qingtongxia, and there are abundant hydropower resources. Below Qingtongxia is the Hetao Plain, where irrigation and shipping are developed. Tuoketuo to Taohuayu in Henan Province is the middle reaches, and there are also abundant hydropower resources. The banks of the Yellow River are the Loess Plateau, with scarce vegetation and serious soil erosion, which is the main source of flood and sediment in the Yellow River. Taohuayu is downstream from the estuary, and most banks have built dikes. Due to sediment deposition, the riverbed is generally 3 ~ 5m higher than the ground on both banks, numbered as 10m, so it is called suspended river. There are many irrigation areas along the coast, and the main stream is also navigable. Near the estuary, the Yellow River's waterway into the sea is continuously silted, extended and diverted, which has a strong role in reclamation. There are ten tributaries with a basin area of more than 65,438+000 km, of which the Weihe River has the largest area and water volume.

3. The Pearl River is composed of four water systems: Xijiang River, Beijiang River, Dongjiang River and Pearl River Delta, which are distributed in six provinces (autonomous regions) of China, namely Yunnan, Guizhou, Guangxi, Guangdong, Hunan, Jiangxi and the northeast of the Socialist Republic of Viet Nam. The mainstream of the Pearl River is the Xijiang River, which originates from Maxiong Mountain in Yunnan and flows into the South China Sea at Modaomen in Zhuhai City, Guangdong Province, with a total length of 22 14km. The whole basin covers an area of 453,700 km, of which China covers an area of 44265.438+0.000km.

The Pearl River Basin is located in the subtropical zone, with mild climate and abundant water resources. The average annual runoff for many years is 336 billion m, second only to the Yangtze River, ranking second in the country. The average annual precipitation for many years is 1477mm. During the flood season, the precipitation intensity is high and the confluence speed is fast, which is easy to form a basin flood with high peak and long duration, posing a serious threat to the economically developed lower reaches of the Pearl River and the delta region. In the dry season, there will be no rain or little rain for three consecutive months, resulting in spring drought or autumn drought. From Yunnan-Guizhou Plateau to the coast of South China Sea, the Pearl River has a total drop of 2 1.36m, and the theoretical hydropower reserves of the whole basin are 33.48 million kW, mainly concentrated in the lower reaches of Nanpanjiang River in Xijiang River and the reaches of Hongshui River and Qianjiang River. The exploitable hydropower installed capacity is 2,565,438+200,000 kilowatts, which is one of the hydropower development and construction bases in China.

4. Haihe River Basin, located in the north of China, is one of the earliest developed basins in China.

River basin overview Haihe River basin customarily includes Haihe River and Luanhe River. Haihe River system consists of Zhangwei River, Ziya River, Daqing River, Yongding River, Chaobai River, North Canal and Jiyu Canal. It also includes drainage channels in plain areas, such as Haihe River and Ma Jiahe. Luanhe River system includes Luanhe River and Jidong River. Before 1949, except Luanhe River System, Jiyun Canal, Tuhai River and Ma Jiahe, all the other rivers gathered in Tianjin and flowed into Bohai Sea. The river below Tianjin is called Haihe River, and its mainstream is 73 kilometers long. Haihe river basin includes most of Beijing, Tianjin and Hebei provinces, as well as parts of Shanxi, Shandong, Henan, Liaoning and Inner Mongolia Autonomous Region. The total basin area is 310.8 million km (including 264,000 km of Haihe River system and 54,000 km of Luanhe River system). The mountainous area accounts for 60% and the plain area accounts for 40%. Yanshan Mountain and Taihang Mountain come from the northeast.

It is distributed in an arc to the southwest. The Loess Plateau is distributed in the west and north of the mountains. To the east and south of the mountain range is a vast plain. The transition zone between mountains and plains is very short and almost directly connected. The general trend of plain topography is to tilt from southwest, west and north to Bohai Bay near Tianjin. Due to the repeated diversions and invasions of the Yellow River in history, and the influence of the tributaries of this basin, the plain area constitutes a complex terrain with alternating distribution of gentle hills and depressions.

5. Huaihe River is located between the Yangtze River and the Yellow River, with a drainage area of 270,000 kilometers, including Huaihe River system10.9 million kilometers and Yishu Sishui River system of 80,000 kilometers.

River Basin Overview The main stream of Huaihe River originates from Tongbai Mountain in Henan Province and flows into Hongze Lake from west to east. After leaving Hongze Lake, it is divided into two tributaries: one is Yang in Jiangsu via gaoyou lake Shaobo Lake.

The southeast of the city flows into the Yangtze River, which is called the river channel, with the maximum flood discharge capacity of12000 m/s; s； The other tributary flows into the Yellow Sea through the main irrigation canal in northern Jiangsu, with a designed flood discharge capacity of 800m /s, in addition to 300m /s through the abandoned Yellow River, and 3000m /s through the Huaishuxin River to the Xinyi River camera during flood. The total length of the main stream is about 1000km. The main tributaries of the south bank are Shiguan River and Pi River, both of which originate from Dabie Mountain. The main tributaries of the North Shore are Hongru, Sha Ying, Vortex, Yue, Xinbian and Yue. The northeast of Huaihe River Basin is Yishu Sishui System, which originated from Yimeng Mountain and flowed into Huaihe River. From the end of 12 century to the middle of 19 century, the Yellow River changed its course and occupied Sihe River below Xuzhou and Huaihe River below Huaiyin. During this period, due to the siltation and elevation of the Yellow River bed, the drainage of Huaihe River, yi river River, Shuhe River and Sihe River was blocked, and Hongze Lake, Roman Lake and Nansi Lake (Nanyang, Dushan, Zhaoyang and Weishan Lake) were formed, which made the Huaihe River flow into the river, while Yishu River found another way out and flowed into the East.

Sea. After the regulation since 1949, part of the water in the upper reaches of Yishu River is diverted to Xinshu River, and the rest enters the sea through Xinshu River. Sihe River flows into Nansi Lake, enters Rome Lake through the canal, accepts the Yi River, and discharges into Xinyi River through Zhangshan Gate.

6. Songhua River is the main river in northeast China, which flows through Jiamusi and Harbin and flows into Heilongjiang near Tongjiang, with a total length of 939km.

General situation of the river basin covers an area of 546,000 kilometers, belonging to Inner Mongolia, Jilin and Heilongjiang provinces and autonomous regions, of which mountainous areas account for 6 1%, hills account for 15% and plains account for 24%. There are Sanjiang Plain and Songnen Plain on the east and west sides of the basin, with fertile land and contiguous grasslands. There are about 200 million mu of cultivated land in the whole basin, and 30 million mu of wasteland can be reclaimed; Daxinganling mountain area is densely forested and is a famous forestry base in China. Sanjiang Plain is rich in coal resources, with raw coal output 1985.

60 million t; Songnen Plain is the main oil base in China, and Daqing Oilfield is built here. The crude oil output of 1985 accounts for half of the total crude oil output in China. The climate of the basin is cold and long in winter and warm and rainy in summer. The annual average temperature is -3 ~ 5℃, the highest can reach 40℃, and the lowest can reach -50℃. The annual precipitation is generally 500mm, 800mm in the southeast mountainous area and only 400mm in the southwest plain, which varies greatly during the year, with obvious alternating rules of high and low rainfall. The river runoff is about 78 billion m, and the groundwater resources are about 37 billion m. After deducting repeated water use, the total water resources are about 95 billion m. The natural disasters in the basin are mainly floods and droughts, with floods in the east and droughts in the west. The floods in the eastern Sanjiang Plain are the worst, with an average of once every two years. The drought in Songnen Plain in the west is severe, mainly in spring.

7. Liaohe River is located in the southwest of northeast China. Originated in Hebei Province, it flows through Inner Mongolia Autonomous Region, Jilin Province and Liaoning Province and flows into Bohai Sea.

General situation of the basin The whole basin consists of two water systems: one is the East and West Liaohe River, which becomes the main stream of the Liaohe River after confluence at Wufudian, and flows into the sea from Panshan Mountain via Shuangtaizi River, with a length of 516 km; The other is that Hunhe River and Taizi River meet at Sancha River and enter the sea from Yingkou via Daliao River, with a total length of 94 kilometers. The main stream of Liaohe River comes to Shui Yuan, forks near Liujianfang, and flows into Daliao River via Wailiao River. 1958 After the upper reaches of Wailiao River were cut off, the main stream was no longer connected with Hunhe River and Taizi River, and became independent water systems. The total basin area is 2,654.38+900,000 square kilometers. Above Zhengjiatun of Xiliaohe River is the upper reaches of Liaohe River, with an area of 654.38+0.36 million km. The climate in this area is dry, and the main tributaries are Laoha River, Jiaolai River and Xilamulun River. Among them, the Laoha River and the Jiaolai River are located in the western Liaoning mountain area and the loess hilly area in northern Hebei, with vegetation coverage less than 30% and serious soil erosion. The upstream cultivated land is about 26 million mu, which is mainly used for dry farming and animal husbandry. The middle and lower reaches of the basin cover an area of 83,000 square kilometers. On the east side of the main stream of Liaohe River is a rocky mountain area with good vegetation and abundant rainfall. There are main tributaries such as Dongliao River, Zhaosutai River, Qinghe River and Chaihe River, and the water systems of Hunhe River and Taizi River cover an area of 52,600 kilometers, accounting for only about 24% of the whole basin, and the annual runoff accounts for about 70% of the total runoff of the whole basin. There are many loess dunes on the west side of the main stream, and the main tributaries are Xiushui River, Liuhe River and Raoyang River, among which Liuhe River is the main sand-producing area in the middle and lower reaches due to serious soil erosion. The middle and lower reaches are economically developed, including important industrial cities such as Shenyang, Fushun and Anshan, large coal mines such as Fushun and Liaoyuan, power plants such as Liaoning and Qinghe, iron and steel enterprises such as Anshan and Benxi, and major railway trunk lines and highway networks such as Liaohe Oilfield, Shenshan and Changda. There are 43 million mu of cultivated land, including 6.2 million mu of paddy fields, which are the main agricultural areas in the Liaohe River Basin. 1988.

8. Taihu Lake Basin is a tributary water system with Taihu Lake as the center and Huangpu River as the main drainage channel in the lower reaches of the Yangtze River. The boundary of the basin extends to Tianmu Mountain and Maoshan Mountain in the west, the Yangtze River estuary in the north, the East China Sea in the east and Hangzhou Bay in the south, with a total area of 36500km.

Taihu Lake Basin belongs to the subtropical monsoon climate zone, and the precipitation is mainly rainy in spring and summer (May and July) and typhoon rain in summer and autumn (August to 65438+1October), with an average annual precipitation of about1100 mm. The general trend of the terrain is to tilt from west to east. There are mountains and hills in the west, plains and depressions in the middle and east, accounting for 22% and 78% of the total basin area respectively, and dikes or seawalls are built on the north, east and south sides. The elevation of the mountain is generally 200 ~ 500 m; The elevation of hills is generally10 ~ 30m; The elevation of the plain is generally 4 ~ 8m, and the lowest elevation is only 2.5 ~ 4m, such as the eastern and southeastern areas of Taihu Lake. The main water systems in this area include the Tiaoxi and Nanxi water systems flowing into Taihu Lake, the Huangpu River water system flowing out of Taihu Lake and the Yangtze River water system connecting Taihu Lake. The basin plain is alluvial by the Yangtze River, Qiantang River and Taihu Lake. Its characteristics are as follows: ① There are many lakes, with a total of 189 in the whole region, with an area of about 323 1km, among which Taihu Lake is the third largest freshwater lake in China, with a water depth of 2-3 m and a volume of 4.43 billion m, which is the center of flood regulation and low water supply in the basin; (2) The water network is dense, and the river density reaches 3 ~ 4 km/km. River network interweaves vertically and horizontally to communicate with lakes and play the role of storage and discharge; (3) The river slope is very gentle and supported by tides, which is easy to cause floods, and the change of water level often has a great influence on regional governance. 1954, the biggest flood occurred in the basin since the 20th century. The highest water level in Jiaxing is 4.38 meters, and the highest water level in Dianba area in the east of Taihu Lake is 4.2 meters, flooding 7.85 million mu of farmland. Most cities along the lake are threatened by the tidal level of Huangpu River, and the urban area has been flooded three times since 1949. Taihu Lake Basin, together with Nantong City in northern Jiangsu, is called Yangtze River Delta Economic Zone. There are Shanghai, Suzhou, Wuxi and Changzhou in Jiangsu, Hangzhou, Jiaxing and Huzhou in Zhejiang. 1985, with a total population of 32.6 million and a density of 893 people/km; More than 26.5 million mu of cultivated land, including paddy field 2 1 10,000 mu; Gross industrial and agricultural output value accounts for 13% of the country, and fiscal revenue accounts for 1/6. Shanghai Port in the basin is the largest port in China. The inland waterway is 3,000 kilometers long.

1983, the water transport volume reached 65,438+73 million tons, ranking first in China in terms of output value per unit land area, fiscal revenue and water transport volume, and being praised as the "Golden Triangle" of China by the economic circles.