The basic information is 5,464 kilometers long, the source is 4,8 meters above sea level, the average flow rate is 1,774.5 cubic meters per second, and the drainage area is 752,443 square kilometers. The source of the information is Qinghai Province, which flows into the Bohai Sea. The dividing point of the middle and lower reaches is the estuary, and the old Mengjin is also called: the source of the south of the Yangtze River: the northern foot of the Bayan Kara Mountains in Qinghai Province
Natural characteristics
The Yellow River is the second longest river in China. Originating from bayan har, Qinghai, the main stream runs through nine provinces and autonomous regions and flows through Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi, Henan and Shandong, with a total length of 5,464 kilometers, a drainage area of 75, square kilometers, an annual runoff of 57.4 billion cubic meters and an average runoff depth of 79 meters. However, the water volume is not as large as that of the Pearl River, and there are 35 main tributaries along the way. The larger tributaries are in the upper reaches, including Huangshui River and Taohe River, Qingshui River, Fenhe River, Weihe River and Qinhe River in the middle reaches, and Yihe River and Luohe River in the lower reaches. There is a lack of lakes on both sides of the river, the area of the lower reaches of the Yellow River is very small, and few rivers flow into the Yellow River. The estuary of the Yellow River is 15 meters wide, generally 5 meters, only 3 meters in the narrower part, and the water depth is generally 2.5 meters. In some places, the depth is only 1.2 ~ 1.3 meters.
Geographical environment
From Heyuan to Guide, there are many mountains and grassland plateaus, which belong to the Qinghai-Tibet Plateau. The peaks are all over 3, meters above sea level, and the headwater valley is over 4,2 meters above sea level. The topography on both sides of the headwater valley is gentle and the drainage is not smooth, forming a large area of marshes and many lakes. Guide's section from Mengjin River is the Loess Plateau, with Lvliang Xibo, Weihe Valley in the south, Ordos Plateau in the north and Lanzhou Valley in the west. The elevation of the Loess Plateau is generally 1,-1,3 meters, the landform is undulating, the slope is steep and deep, the slope of the gully ground is 15-2 degrees, the gully area accounts for 4-5%, the gully density is 3-5 kilometers per square kilometer, and the cutting depth is more than 1 meters. Below Mengjin, it enters the low-lying North China Plain, with an altitude of no more than 5 meters. After entering the downstream, the river channel is flat, with an average gradient of only .12%. The water flow slows down and a large amount of sediment is deposited, which is 4-5 meters higher than the ground. Due to the repeated diversion of the Yellow River, the fan-shaped ancient riverbed and ancient natural dike have become inclined plains with alternating slow hills and depressions, and the depressions are relatively open and flat.
River Basin Overview
The Yellow River reaches Hekou Town, Tuoketuo County, Inner Mongolia Autonomous Region from its source, with a length of 3,472 kilometers; From Hekou Town to Taohuayu, Zhengzhou, Henan Province, the middle reaches, with a river length of 126 kilometers; Below Taohuayu is the downstream, with a river length of 786 kilometers. (There are many opinions about the demarcation between the upper, middle and lower reaches of the Yellow River, and the division scheme of the Yellow River Conservancy Commission is adopted here.) The Yellow River traverses China from east to west, with a basin of 1,9 kilometers long from east to west and 1,1 kilometers wide from north to south, with a total area of 752,443 square kilometers.
The Yellow River, like a lion with its back arched and its head held high, crosses the mountains of Qinghai and Gansu provinces from the Qinghai-Tibet Plateau. Hetao Plain across Ningxia and Inner Mongolia; Pentium in the mountains and valleys between Shanxi and Shaanxi; Break through the "Dragon Gate", turn around at the foot of Huashan Mountain in Xiyue, cross the North China Plain, and rush to the coast of Bohai Sea. It flows through 9 provinces and regions, gathers more than 4 main tributaries and more than 1, streams, with a journey of 5,464 kilometers and a drainage area of more than 75, square kilometers, making it the second longest river in China. The average annual precipitation in the whole basin is about 4 mm, while the average annual runoff of the Yellow River is only 57.4 billion cubic meters, ranking eighth among Chinese rivers. There are more than 2 million mu of cultivated land and a population of about 1 million in the basin, together with the downstream areas along the Henan and Shandong rivers.
the average natural runoff of the whole Yellow River for many years is 58 billion cubic meters, the average annual runoff depth of the basin is 77 mm, the per capita water consumption of the basin is 593 cubic meters, and the per mu water consumption of cultivated land is 324 cubic meters.
The middle reaches of the Yellow River flow through the Loess Plateau, and tributaries bring in a lot of sediment, making the Yellow River the most sediment-laden river in the world. The maximum annual sediment discharge reached 3.91 billion tons (1933) and the maximum sediment concentration was 92 kg/m3 (1977). The average sediment discharge of Sanmenxia Station for many years is about 1.6 billion tons, with an average sediment concentration of 35 kg/m3.
Main tributaries
The main tributaries of the Yellow River are Baihe, Heihe, Huangshui, Zuli, Qingshui, Dahei, Kuye, Wuding, Fenhe, Weihe, Luohe, Qinhe and Dawenhe.
The main lakes
are Zhaling Lake, Eling Lake, Wuliangsuhai Lake and Dongping Lake.
mainstream canyons
There are 3 canyons in the mainstream of the Yellow River, 28 in the upper reaches and 2 in the middle reaches. The lower reaches flow through the North China Plain, and there are no canyons. The canyon section of the main stream is 177 kilometers long, accounting for 31.2% of the total length of the main stream.
biological resources
There are 121 species (subspecies) of fish in the main stream of the Yellow River, and there are 98 species of pure freshwater fish in the main stream, accounting for 78.4% of the total. The main economic fish are naked spotted carp, flat-edged swallow-toothed fish, thick-lipped naked heavy-lipped fish, naked-lipped fish of the Yellow River, Yarrow Warburg, tong yu (pigeon fish) in the north, carp and crucian carp. There are only 16 species of fish in the upper reaches of the Yellow River, and their composition is relatively simple, including Schizothorax fish, Yarrow fish and Loach in CYPRINIDAE and Loach. Fish in the middle and lower reaches are generally similar, and they are mainly CYPRINIDAE. There are 71 species of fish in the middle reaches, but there are no typical plain fish such as silver carp, bighead carp, bream and bream. There are schizothorax fish and loach in the upper reaches of the middle reaches, and there are 78 species of fish in the lower reaches, including many kinds of fish crossing the estuary and brackish water. According to the survey data of tributaries of the Yellow River, according to the fish statistics of Taohe River in Gansu, Weihe River in Shaanxi and Jinghe River, there are 3 species in Weihe River, followed by 11 species in Taohe River and only 4 species in Jinghe River. Most of the tributaries in the upper and middle reaches are small fishes of CYPRINIDAE and loach, and a few of them are Tasmanian and catfish, and the economic fishes are carp, crucian carp, yarrow fish and catfish.
Fishery production
The main catch species of the Yellow River have also changed. In the main stream, carp has the highest yield in history, and the "Yellow River Carp" is famous in China, but now the yield has dropped significantly. Before the 196s, carp in Shanxi-Shanxi reach of the middle reaches accounted for 6-7% of the catch, ranking first in the catch composition. According to the changes of the catch in the port section of the Yellow River in Shaanxi in 1981-82 in recent ten years, carp only accounted for 21% of the catch, and catfish replaced the main position, accounting for 41.1%. Followed by Pelteobagrus fulvidraco, accounting for 26.3%. In 1983, the catch of the Yellow River in Pinglu County, Shanxi Province was investigated. Among them, carp was only 2%, while catfish was as much as 6%, which became the main catch. Carp accounted for 5 ~ 7% of the total output in the downstream Shandong section in the early 195s, but it decreased to 15% in the 196s, and only 7.1% in 81 ~ 82 according to the survey. The situation of fishing labor force in the eight provinces and regions where the Yellow River mainly flows is as follows: except Qinghai Province, which has not been counted, the fishing professional labor force in Gansu, Ningxia, Inner Mongolia, Shanxi, Shaanxi, Henan, Shandong and other seven provinces and regions was 26,964 in 198, and it decreased to 11,32 in 1983, accounting for 3.% and 2.1% of the total similar labor force in China; The number of part-time fishing laborers was 24,843 in 198, and it increased to 25,873 in 1983, accounting for 8.9% and 5.7% of the total number of similar laborers in China. Over the past 3 years, the resources of the main economic fish carp in the Yellow River have decreased greatly, and the composition of its catch groups has also changed accordingly. In the early 198s, most of the carp caught in the Tongguan port section of the Yellow River were 3 years old, with an average of .7 kg per fish accounting for 44.7%, followed by 4 years old, with an average weight of 1.5 kg accounting for 28.4%.
fishing method: fishing method, the fishing gear used in fishery production in the main stream of the Yellow River, is mostly gill net in the upper and middle reaches, and there are also beach seine. The gill net can be divided into single layer and three layers, and the triple gill net is more efficient. In addition, there are many kinds of rolling fishing, fishing hooks and clips, only four or five in the middle reaches.
fishing area characteristics: upstream: 8 species of Schizothorax subfamily and Misgurinae; Middle reaches: carp, crucian carp and catfish; Downstream: Coilia ectenes, Cyprinus carpio, Grass Carp and Catfish.
Upstream: from Heyuan to Guide, there are many mountains and grassland plateaus on both sides, with the elevation above 3,m and the peak exceeding 4,m. The river course is "S", and within 4km of the headwater, there are many lakes, grasslands and marshes on both sides, with stable clear water flow, low water consumption, large water production and many lakes, with the largest lakes, Xingsuhai Lake and Eling Lake. Fish resources have not been exploited for a long time.
Middle reaches: Guide to Mengjin, mostly passing through high mountains and canyons, with rapid water flow and steep slope. The valley from Guide to Liujiaxia is extremely deep cut, with a river width of 5-7 meters and a narrowest point of less than 15 meters and a valley depth of 1-5 meters. The water is swift, narrow and steep, and it is rich in hydraulic resources. A large reservoir was built on the canyon, and the Yellow River entered the river after leaving Qingtongxia. The Yellow River flows through Hekou Town, turns south, passes through the Qin and Jin canyons, and reaches Longmen with a total length of only 718 kilometers, with a drop of 611 meters, with a large gradient. The 13-kilometer reach from Longmen to Tongguan has a large amount of water, such as Nafen, Wei, Jing and Luozhu, with a large amount of sediment deposition, unstable river course and rich carp resources. The middle reaches pass through the loess high slope, carrying a large amount of sediment, which is a great harm to the downstream.
Downstream: the section from Mengjin to North China Plain is the downstream, with a total length of 874 kilometers. The river channel is wide and flat, with slow water flow and siltation. The riverbed is 4-5 meters above the ground on average, which is the fishing river with the most abundant fish resources, including migratory fish in the estuary, riverine fish, sedentary fish, brackish water fish and aquatic fish.
river segmentation
there are many opinions about the boundary between the upper, middle and lower reaches of the yellow river. The Yellow River Conservancy Commission divides Hekou Town and Taohuayu into upper, middle and lower reaches. Traditional middle school textbooks divide Hekou Town and Mengjin into upper, middle and lower reaches. Yang Liankang, a scholar, thinks that Qingtongxia and Mengjin are more suitable. Scholar Xu Shaoli advocated Jiayingguan in Wuzhi County, Jiaozuo City, Henan Province as the dividing line between the middle and lower reaches of the Yellow River. The following is the division plan of the Yellow River Water Conservancy Commission.
Upstream
The reach of the Yellow River above Hekou Town, Tuoketuo County, Inner Mongolia is the upper reaches of the Yellow River. The total length of the upper reaches is 3,472 kilometers, and the drainage area is 386, square kilometers, accounting for 51.3% of the total of the Yellow River. The total drop of the upper reaches is 3,496 meters, with an average gradient of 1 ‰; There are 43 large tributaries (with a basin area of more than 1 square kilometers) in the river reach, and the runoff accounts for 54% of the whole river; The upper reaches of the Yellow River account for only 8% of the annual sediment of the whole river, with more water and less sediment, which is the clear water source of the Yellow River. The upper reaches of the river are controlled by Animaqing Mountain, Xiqiao Mountain and Nanshan Mountain in Qinghai and bend in an S-shape. The upper reaches of the Yellow River can be divided into three parts according to the different river characteristics: the source section, the canyon section and the alluvial plain.
The upper part from Kariqu in Qinghai to Longyangxia in Guide in Qinghai is the Heyuan section. Heyuan section starts from Kariqu, passes through Xingsuhai, Zhaling Lake and Eling Lake to Maduo, bypasses Animaqing Mountain and Xiqing Mountain, and passes through Longyangxia to reach Guide in Qinghai. Most of the rivers in this section flow through the plateau of three or four kilometers, and the rivers are tortuous, with lakes, swamps and grass beaches on both sides. The water quality is clear, the water flow is stable and the water yield is large. There are Zhaling Lake and Eling Lake in the reach, both of which are above 4,26 meters above sea level, with storage capacity of 4.7 billion cubic meters and 1.8 billion cubic meters respectively, making them the largest plateau freshwater lakes in China. From Maduo, Qinghai Province to Maqu, Gansu Province, the Yellow River flows through the ancient basin and low hills between bayan har and Animaqing Mountain. Most of the river reaches have wide valleys, with occasional canyons. From Maqu, Gansu Province to Longyangxia, Guide, Qinghai Province, the Yellow River flows through alpine valleys, with rapid water flow and rich hydraulic resources. Baihe and Heihe rivers, tributaries originating from Minshan, Sichuan, flow into the Yellow River in this section.
The section from Longyangxia in Qinghai to Qingtongxia in Ningxia is a canyon section. This section of the river flows through mountainous hills, and due to the different rock properties, valleys and wide valleys alternate: valleys are formed in hard gneiss, granite and Nanshan metamorphic rocks, and wide valleys are formed in loose sand shale and red rock series. There are 2 canyons in this section, including Longyang Gorge, Jishi Gorge, Liujia Gorge, Bapan Gorge and Qingtong Gorge. Both sides of the canyon are cliffs, with narrow riverbed, large river gradient and fast current. From Guide to Lanzhou, this section is one of the concentrated sections of the three tributaries of the Yellow River, with important tributaries such as Taohe River and Huangshui River flowing into it, which greatly increases the water volume of the Yellow River. The main reach from Longyangxia to Xiaheyan in Ningxia is a "mine-rich" area of the Yellow River, and it is also one of the key hydropower bases in China.
The section from Qingtongxia in Ningxia to Hekou Town in Tuoketuo County, Inner Mongolia is an alluvial plain. After leaving Qingtongxia, the Yellow River flows northeast along the northwest boundary of Ordos Plateau, and then reaches Hekou Town eastward. Most of the areas along the river are desert and desert grassland, and there is basically no tributary injection. The riverbed of the main stream is gentle and the water flow is slow. There are large alluvial plains on both sides, namely the famous Yinchuan Plain and Hetao Plain. There are floods and ice flood disasters in the plain along the river to varying degrees. Hetao Plain starts from Xiaheyan in Ningxia in the west and reaches Hekou Town in Inner Mongolia in the east, with a length of 9 kilometers and a width of 3-5 kilometers. It is a famous irrigation area for diverting water from the Yellow River, with a long irrigation history. Since ancient times, there has been a saying that "the Yellow River is full of hazards and only one set is rich".
Middle reaches
The reach of the Yellow River between Hekou Town, Tuoketuo County, Inner Mongolia and Taohuayu, Zhengzhou, Henan Province is the middle reaches of the Yellow River, with a length of 1,26 kilometers and a drainage area of 344, square kilometers, accounting for 45.7% of the total drainage area; The total drop of the middle reaches is 89 meters, with an average gradient of .74 ‰; There are 3 large tributaries in the river; The increased water volume accounts for 42.5% of the Yellow River's water volume, and the increased sediment volume accounts for 92% of the whole Yellow River's sediment volume, which is the main source of the Yellow River's sediment.
Hekou Town to Yumenkou is the longest continuous canyon on the main stream of the Yellow River-Shanxi Canyon. Most of the tributaries in the reach flow through the loess hilly and gully region, which is the main source of coarse sediment in the Yellow River, and 9 million tons of the annual average sediment transport of the whole river come from this interval. This reach is the second largest hydropower base of the Yellow River because of its large gradient and abundant hydraulic resources. There is a famous Hukou Waterfall in the lower part of the canyon, with a deep trough width of only 3-5 meters and a drop of about 18 meters on the low water surface, which is magnificent.
From Yumenkou to Sanmenxia, the Yellow River flows through Fenwei Plain, the valley widens and the water flow is slow. On both sides of the reach are Weibei and Jinnan loess tablelands, which are important agricultural areas in Shaanxi and Shanxi provinces. This reach has accepted Fenhe River, Luohe River, Jinghe River, Weihe River, Yiluo River, Qinhe River and other important tributaries, and is one of the main sources of sediment in the lower reaches of the Yellow River, with an average annual sediment yield of 55 million tons for many years. The reach is 132.5 kilometers from Yumenkou to Tongguan (that is, the small north main stream of the Yellow River). The erosion and siltation changes dramatically, and the river swings unsteadily from side to side. Constrained by mountains near Tongguan, the river valley suddenly narrows, forming a natural bayonet with a width of only over 1 meters, and the riverbed in Tongguan is yellow and high.