Information about the Yellow River

[Edit this paragraph] Basic information

The Yellow River has a total length of 5,464 kilometers and a drainage area of 752,442.76 square kilometers. It meanders through nine provinces in northern China. Seen from the air, it looks like a huge "Ji", which is a unique totem of our nation-the dragon. Kariqu and Yuegu Zonglie Canal at the northern foot of bayan har are the main sources of the Yellow River, which originated from Yaradazi Peak in Bayan Kara Mountains. The main stream is 4,675 kilometers long, with an average flow of 1774.5 cubic meters per second, and flows into the Bohai Sea in Kenli County, Dongying City, Shandong Province. The dividing point of the upper and middle reaches is Hekou Town, Inner Mongolia Autonomous Region, and the dividing point of the middle and lower reaches is Old Jin Meng, Henan Province. The estuary of the Yellow River is1500m wide, generally 500m, with a narrow part of only 50m and a water depth of 2.5m.. In some places, the depth is only 1.2 ~ 1.5 meters.

[Edit this paragraph] Natural features

geographical position

The Yellow River basin is bounded by latitude 32-42 N and longitude 96- 1 19 E, with a difference of latitude 10 between north and south and longitude 23 between east and west. The basin covers an area of more than 752,000 square kilometers, with a total length of 5,464 kilometers and a drop of 4,830 meters from the source to the estuary. Rocky mountain area accounts for 29%, loess hilly area accounts for 46%, sandstorm area accounts for 1 1%, and plain area accounts for 14%.

The Yellow River originated in Bayankala, Qinghai-Tibet Plateau, and its main stream flows through Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi, Henan and Shandong provinces and flows into the Bohai Sea. The annual runoff is 57.4 billion cubic meters and the average runoff depth is 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, with Huangshui River, 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. Due to the lack of lakes and high riverbeds on both banks, there are few rivers flowing into the Yellow River, so the area of the lower reaches of the Yellow River is very small.

Heyuan to Guide is a mountainous and grassland plateau; The ownership of the Qinghai-Tibet Plateau; Above 3000 meters above sea level; Mountain peaks above 4000 meters; Source valley at an altitude of 4200 meters. Guide's reach from Jinmeng River is the Loess Plateau, with the western slope of Lvliang in the east, Weihe Valley in the south, Ordos Plateau in the north and Lanzhou Valley in the west. The elevation of the Loess Plateau is generally at 1, 000 ~ 1, 300 meters, with uneven terrain and deep slopes. The gully slope is 65,438+0.5 ~ 20 degrees, and the gully area accounts for 40 ~ 50%. Gully density is 3 ~ 5 kilometers per square kilometer, and the cutting depth is more than 1 meter. Below Jin Meng, it enters the low-lying North China Plain, with an altitude of no more than 50 meters. After entering the downstream, the river channel is flat, and the average gradient is only 0. 12%. The water flow slows down, a lot of sediment is deposited, and the riverbed is 4 ~ 5 meters above the ground. Due to the repeated diversions of the Yellow River, fan-shaped ancient riverbeds and ancient natural dikes are alluvial on the ground, becoming an inclined plain with alternating gentle hills and depressions, and the depressions are relatively open and flat.

The Yellow River runs from Guide to Minhe at an altitude of 3,000 to 1.600 meters, and enters Gansu from Minhe Xiachuankou. The climate in this section is mild and humid, and it has the reputation of "small south of the Yangtze River on the plateau", and the water flow is crystal clear, and it is also known as "the Yellow River is precious in Deqing". Ningxia Plain in Ningxia and Hetao Plain in Inner Mongolia are called the Yangtze River because they are located in the upper reaches of the Yellow River, rich in water resources, convenient for irrigation, developed in agriculture and rich in aquatic plants.

River basin survey

The Yellow River reaches Hekou Town, Tuoketuo County, Inner Mongolia Autonomous Region, with a total length of 3,472 kilometers. The middle reaches are Hekou Town to South Mengjin of Hukou Waterfall, with a length of 1206 km. Below Taohuayu is the downstream, with a river length of 786 kilometers. There are many opinions on the division of the upper, middle and lower reaches of the Yellow River, and the division scheme of the Yellow River Water Resources Commission is adopted here. The Yellow River runs through China from east to west, with a length of 1.900 km from east to west and a width of1.654,38+0.000 km from north to south, with a total area of 752,443 square kilometers.

The Yellow River, like a lion with his 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 ravine between Shanxi and Shaanxi; Break through the "Longmen", turn around at the foot of Huashan Mountain in Xiyue, cross the North China Plain, and head for the coast of Bohai Sea. Flowing through 9 provinces; It has gathered more than 40 major tributaries and more than 65,438+0,000 streams and rivers, with a journey of 5,464 kilometers and a drainage area of more than 750,000 square kilometers, making it the second longest river in China. The average annual precipitation in the whole basin is about 400 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 200 million mu of cultivated land in the basin, and the population is about 654.38+0 billion along the Yulu River downstream.

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 volume of the basin is 593 cubic meters, and the cultivated land is 324 cubic meters.

The middle reaches of the Yellow River flow through the Loess Plateau. Due to soil erosion, tributaries bring a lot of sediment, making the Yellow River the largest river with sediment concentration in the world. The annual maximum sediment discharge is 3965438+ 1 100 million tons (1933), and the maximum sediment concentration is 920kg/m3( 1977). The average sediment discharge of Sanmenxia Station for many years is about 65.438+0.6 billion tons, and the average sediment concentration is 35 kg/m3. According to world record association, China, the Yellow River has the largest sediment concentration.

branch

The main tributaries of the Yellow River are Baihe, Heihe, Huangshui, Zuli, Qingshui, Dahei, Kuye, Wuding, Fenhe, Weihe, Luohe, Qinhe and Dawenhe. Weihe River is the largest tributary of the Yellow River.

Major lakes

There are Zhaling Lake, Eling Lake, Wuliangsuhai Lake and Dongping Lake.

Main stream canyon of satellite map of yellow river basin

There are 30 canyons in the main stream of the Yellow River, 28 in the upper reaches and 2 in the middle reaches. The lower reaches flow through the North China Plain without canyons. The canyon section of the main stream is 1707 km long, accounting for 3 1.2% of the total length of the main stream.

Biological resources

Fish 12 1 species (subspecies) in the main stream of the Yellow River, and 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 swallowtail, thick-lipped naked heavy-lipped fish, yellow river naked-lipped fish, yarrow, northern Tongyu, carp, crucian carp and so on. There are only 16 species of fish in the upper reaches of the Yellow River, and the composition is relatively simple. There are only Schizothorax fish, yarrow fish and loach in CYPRINIDAE and Misguridae. Fish in the middle and lower reaches are generally similar, mainly CYPRINIDAE. There are 7/kloc-0 species of fish in the middle reaches, and there are no typical plain fish such as silver carp, bighead carp, bream and bream. There are Schizothorax and Misgurnus anguillicaudatus in the upper reaches of the middle reaches, and 78 species of fish in the lower reaches, including a variety of fish crossing estuaries 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 30 species in Weihe River, followed by Taohe River 1 1 species, and only 4 species in Jinghe River. Most of the tributaries in the middle and upper reaches are small fishes of CYPRINIDAE and Misgurnus, a few are Tasmanian fishes and catfish, and the economic fishes are carp, crucian carp, yarrow fish and catfish.

Historically, the Yellow River Basin has long been regarded as the political, economic and cultural center of China and the cradle of China culture. Frequent disasters in history also make the Yellow River known as "the worry of China". From 602 BC to 1938, the Yellow River burst 1590 times and changed its course 26 times. On average, there are two gaps in three years and a big diversion in a hundred years. 1938, the Yellow River changed its course, and the river went south to seize the Huai River, which flooded a large area of land in eastern Henan, northern Anhui and northern Jiangsu, with a population of12.5 million and 890,000 deaths.

Precautions:

In recent years, the organisms in the Yellow River waters have been destroyed, and now there are less than 100 species of fish. The technicians of Lanzhou Fishery Technology Extension Center believe that the ecological environment in the upper reaches of the Yellow River has deteriorated and soil erosion has led to a large sediment concentration in the Yellow River. Due to drought and lack of rain, the water volume of the Yellow River is decreasing. Wastewater pollution in industrial towns; Artificial fishing and other factors are the reasons for the decrease of water quantity in the Yellow River.

In order to restore the ecology of the Yellow River and protect biological resources, the Fisheries Department of Gansu Provincial Agriculture and Animal Husbandry Department began to implement the "Proliferation and Release" plan for the Gansu section of the Yellow River in 2000. According to the person in charge of the fishery department, the number of fish released has increased from more than 7 million last year to 8 million this year, with carp, catfish, grass carp and bighead carp as the main targets.

River division

There are different 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 Jin Meng into upper, middle and lower reaches. Scholar Yang thinks Qingtongxia and Harmony are more suitable. Scholar Xu 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 upper reaches of the Yellow River are above Hekou Town, Tuoketuo County, Inner Mongolia. The total length of the upper reaches is 3,472 kilometers, and the basin area is 386,000 square kilometers, accounting for 5 1.3% of the total Yellow River. The total upstream drop is 3496m, with an average gradient of1‰; There are 43 large tributaries (basin area 1000 square kilometers or more), and the runoff accounts for 54% of the whole river; The upper reaches of the Yellow River only account for 8% of the annual sediment discharge 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 Qingshan Mountain, Xiqiao Mountain and Nanshan Mountain in Anima, Qinghai, with an S-shaped bend. According to the different characteristics of rivers, the upper reaches of the Yellow River can be divided into three parts: source section, canyon section and alluvial plain section.

The upper part of Qinghai Kariqu to Qinghai Guide Longyangxia is the Heyuan section. Heyuan section starts from Kariqu, passes through Xingsuhai, Zhaling Lake and Eling Lake to Maduo, bypasses Qingshan and Xiqingshan in Anima, and reaches Guide in Qinghai via Longyangxia. 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 above 4260 meters above sea level, with storage capacity of 4.7 billion cubic meters and 654.38+0.08 billion cubic meters respectively, which are the largest plateau freshwater lakes in China. The Yellow River runs from Maduo, Qinghai to Maqu, Gansu, through the ancient basin and low hills between Bayan Kara and Animaqing Mountain, with wide valleys and occasional canyons in most sections. The Yellow River runs from Maqu, Gansu Province to Longyangxia, Guide, Qinghai Province, and flows through high mountains and canyons, with fast-flowing water and abundant hydraulic resources. Baihe and Heihe rivers, tributaries originating in Minshan, Sichuan, join 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. Due to different rock properties, river valleys and wide valleys appear alternately: river valleys are formed in hard gneiss, granite and Nanshan metamorphic rocks, while wide valleys are formed in loose sand shale and red rock series. There are 20 canyons in this section, including Longyang Gorge, Jishi Gorge, Liujiaxia Gorge, Bapan Gorge and Qingtongxia. There are cliffs on both sides of the canyon, with narrow riverbed, steep river slope and rapid water flow. From Guide to Lanzhou, this section is one of the concentrated reaches of the three major tributaries of the Yellow River, and the inflow of important tributaries such as Taohe River and Huangshui River has greatly increased the water volume of the Yellow River. The reach from Longyangxia to Xiaheyan River in Ningxia is a "mine-rich" area of the Yellow River and one of the important hydropower bases in China.

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 deserts and desert grasslands, and there is basically no tributary injection. The river bed of the main stream is gentle and the water flow is slow. On both sides are large alluvial plains, namely the famous Yinchuan Plain and Hetao Plain. There are floods and ice disasters in the plain along the Yangtze 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 900 kilometers and a width of 30-50 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 disasters and there is only one set of wealth".

middle reaches

The reach of the Yellow River from Hekou Town, Tuoketuo County, Inner Mongolia to Jin Meng, Henan Province is the middle reaches of the Yellow River, with a total length of 1.206 km and a drainage area of 344,000 square meters, accounting for 45.7% of the total drainage area. The total drop in the middle reaches is 890 meters, with an average gradient of 0.74 ‰; This river has 30 major tributaries; The increased water volume accounts for 42.5% of the Yellow River water volume, and the increased sediment volume accounts for 92% of the whole Yellow River sediment volume, which is the main source of the Yellow River sediment.

Hekou Town to Yumenkou is the longest continuous canyon on the main stream of the Yellow River-Shanxi Canyon. Most of the tributaries of this reach flow through the loess hilly and gully region, which is the main source of coarse sediment in the Yellow River. Among the 65.438+0.6 billion tons of sediment transport in the whole river for many years, 900 million tons come from this interval. This reach is the second largest hydropower base of the Yellow River with 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 30~50 meters and a low water level drop of about 18 meters, which is magnificent.

From Yumenkou to Sanmenxia, the Yellow River flows through the Wei Fen Plain, the valley widens and the water flows slowly. The two banks of this river 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, Luo Yi 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 output of 550 million tons. The reach is located in the channel from Yumenkou to Tongguan (that is, the small north main stream of the Yellow River) 132.5km, with drastic changes in erosion and deposition, and the channel is very unstable from side to side. Constrained by the mountains near Tongguan, the valley suddenly narrows, forming a natural bayonet with a width of only 1000 meters. The level of Tongguan river bed is closely related to the changes of erosion and deposition in the Xiaobei main stream of the Yellow River and the lower reaches of the Weihe River, so the hydrological term "Tongguan elevation" is used.

Sanmenxia to Taohuayu section is divided into two parts from Xiaolangdi: above Xiaolangdi, the river is between Zhongtiao Mountain and hill, which is the last canyon on the main stream of the Yellow River; The valley below Xiaolangdi gradually widens, which is the transition section of the Yellow River from mountainous area to plain.

lower reaches

The Yellow River below Jin Meng is the lower reaches of the Yellow River, with a total length of 786 kilometers and a drainage area of only 23,000 square kilometers, accounting for 3% of the total drainage area. The total downstream drop is 93.6m, with an average gradient of 0.1.2 ‰; The increased water volume in the interval accounts for 3.5% of the water volume of the Yellow River. Due to the large amount of sediment in the Yellow River, the long-term sedimentation in the lower reaches has formed a world-famous "hanging river on the ground", and the Yellow River has become a watershed between the Haihe River Basin and the Huaihe River Basin. Except for the Dawen River flowing from Dongping Lake, there are no big tributaries in this section.

Except for the low hills between Dongping Lake on the south bank and Jinan, the lower reaches depend on dikes, with a total length of 1.400 km. Historically, the lower reaches of the Yangtze River often burst, which brought heavy disasters to the Chinese nation. Because the lower reaches of the Yellow River flow from southwest to northeast, the north of the Yellow River freezes first in winter, forming ice flood. Ice dams are easily blocked by the overflow of ice, which leads to the overflow of dikes and poses a serious threat.

Below the downstream Lijin is the Yellow River estuary. Due to sediment deposition, the mouth of the Yellow River keeps extending and swinging. At present, the Yellow River estuary is located at the intersection of Bohai Bay and Laizhou Bay, which is a new channel formed by the siltation of Qingshuigou after the artificial diversion of 1976. In recent 40 years, the average sediment transported by the Yellow River to the estuary area is about 654.38+100 million tons/year, and the average net land is 25-365.438+0 square kilometers/year.

[Edit this paragraph] Human characteristics

The Yellow River flows fast, and there is a saying in history that there is no bridge on the Yellow River. Lanzhou is located in the plateau. Since ancient times, the river has been ferried by sheepskin rafts and small wooden boats, which is extremely inconvenient. In the middle of Hongwu in the Ming Dynasty, Song Guogong Shengfeng built a pontoon bridge to the west of Lanzhou, and Gong Weiguo Deng Yu moved the pontoon bridge to the west of 10, which was called "Zhenyuan Bridge" in history. In the 18th year of Hongwu (1385), Yang Lian moved to Kuching Chengguan (now south of Baita Mountain), at the northwest of the city 1 km. The pontoon bridge consists of 24 giant ships, maintained by two iron ropes and four hemp ropes. Ships are paved with wooden boards, so they are called "the first bridge of the Yellow River". So far, there are three cast iron bridge columns with a weight of 10 ton and a length of 5.8 meters.

Until Guangxu thirty-three years (1907), at the suggestion of Peng Yingjia, Gansu Westernization General Office, the pontoon bridge was changed into an iron bridge, which was built by German businessmen, but the transportation and construction of materials were undertaken by China. People from all over the country used camels and big wheels to transport vehicles from Tianjin and other places in the east for thousands of miles, and finally set up the first iron bridge on the Yellow River. The bridge is 250m long and18m wide, and consists of four piers. The pier is made of cement and iron columns and paved with stones, costing more than 362,000 silver. 1954 reinforcement, with curved steel frame arch beam, beautiful structure and more magnificent momentum. There is a yellow river cableway 200 meters west of the bridge, which goes straight to the top of Baita Mountain. Originally named "Lanzhou Yellow River Railway Bridge", 1942 was changed to "Zhongshan Bridge".

The first formal bridge on the Yellow River was Zhengzhou Yellow River Railway Bridge, which was contracted by Belgian engineering company. The bridge started on 1903 and was completed on 1906. When People's Republic of China (PRC) was founded in 1949, there were only three bridges designed and built by foreigners on the Yellow River, namely Zhengzhou Yellow River Railway Bridge, Luokou Yellow River Bridge and Lanzhou Highway Bridge. After the founding of New China, dozens of bridges have been built on the Yellow River, making the moat of the Yellow River a thoroughfare. Lanzhou Yellow River Railway Bridge Main Column

environmental protection

From 3000 BC to 2000 BC (Yangshao culture in the Yellow River valley to Yinxu in Anyang), the geographical environment of the Yellow River valley was suitable for the growth of vegetation and the development of human production and living activities, and the climate environment about 2℃ higher created favorable conditions for the development of crops and vegetation. During this period, there were a large number of lakes such as Leixiaze and Onoze in the middle and lower reaches of the Yellow River. "On Mencius Teng Wengong" once recorded that the Yellow River valley was "lush with plants and animals", and the Guanzhong Plain still had "beautiful mountains and rivers, criss-crossing rivers and numerous talents" until the Warring States period in China (the forest in the middle reaches of the Yellow River in historical period, Shi Nianhai, 198 1 year).

After the Warring States period, with the extensive use of iron farm tools and the migration of Qin's economic center to Guanzhong, the vegetation in the Yellow River basin and the Loess Plateau began to be destroyed. Because the Yellow River Basin has been the center of Chinese civilization for a long time (China Historical Geography, Lan Yong, 2002), and the phenomenon of emphasizing agriculture over grazing in ancient China, the vegetation destruction in the Yellow River Basin has become a long-term and large-scale phenomenon. With the beginning of the cold climate in 1 1 century and the southward movement of the economic center of China, the ecological damage in the Yellow River basin began to decrease, but the forest coverage rate has been difficult to recover to the situation of the 3rd century BC. With the destruction of vegetation, the Loess Plateau began to be eroded by the Yellow River, and a large amount of soil was swept away, forming a surface morphology of thousands of valleys. According to the research of scientists, the Yellow River has changed for two reasons. 1. Since the Qin Dynasty, the temperature in the Loess Plateau has turned cold and the rainstorm has been concentrated. Coupled with the loose structure of loess itself, it is easy to be eroded and collapsed, which encourages soil erosion and makes a lot of sediment enter the Yellow River. Second, the rapid population growth, unrestricted land reclamation and grazing, caused the destruction of forests, grasslands, green vegetation, and the loss of natural protective layer on the Loess Plateau, resulting in serious soil erosion. Every year, 4,000 tons of precious soil is eroded every square kilometer in the Yellow River Basin, which is equivalent to destroying 5.5 million mu of cultivated land a year! What's more, soil erosion has obviously reduced soil fertility, resulting in a large-scale reduction of crop production. The more production is reduced, the more people need to reclaim wasteland: the more land is reclaimed, the more serious soil erosion will be. In this way, the poorer the reclamation, the more sediment the Yellow River will have, and the number of breaches and diversions of the Yellow River will become more and more frequent. The key to harnessing the Yellow River is to control sediment and prevent it from flowing into the Yellow River at will. After the founding of New China, scientists designed a scheme to control the Yellow River. They believe that the Loess Plateau should adhere to the management direction of animal husbandry and forestry. We must protect forest resources and restore lost vegetation as soon as possible. Let everyone know that deforestation is downright self-destructive, and it is necessary to rationally plan and use land and build a large number of water conservancy projects. This multi-pronged approach will certainly prevent soil erosion and make the dream of the Yellow River better realized.

[Edit this paragraph] Development and change

The Yellow River is cut off.

Since 1972, the Yellow River has been frequently cut off. There are many reasons for disconnection, which can be summarized as follows:

1. Global Warming-With the intensification of global warming in recent years, on the one hand, the evaporation of river channels has increased greatly, and on the other hand, the glaciers in the upper reaches melt and absorb a lot of heat in spring and summer, which leads to the local temperature in the inland being lower than normal, and the temperature difference between the inland and the ocean is reduced, which in turn leads to the weakening of the monsoon and the lack of water vapor brought into the inland by the monsoon from the sea surface. Although global warming melts glaciers and increases the upstream water flow, it cannot offset the effects of increased evaporation and weakened monsoon. The water volume in the middle and lower reaches is decreasing year by year.

2. Vegetation destruction-The vegetation in the Loess Plateau is seriously destroyed, and the land lacking vegetation conservation is gradually desertified, with high evaporation. The dried-up groundwater needs to be continuously absorbed and replenished by flowing through rivers.

3. Backward irrigation methods-most of the middle and upper reaches of the Yellow River flow through economically underdeveloped border areas, old and young, lacking the technology and funds for water-saving irrigation, and most of them are flooded, resulting in serious waste of water resources in the Yellow River.

① The upper reaches belong to arid and semi-arid areas, with low precipitation rate, and the middle reaches are the main recharge areas, but the soil erosion is serious, the seasonal changes are great, the downstream area is small, and the recharge amount is small;

(2) The population growth in the basin is fast, and the population growth rate far exceeds the grain growth rate;

In recent decades, with the development of society, the industrial and urban water consumption along the Yellow River has been increasing, and the irrigation area of the Yellow River has been expanding.

(4) The reservoir regulation capacity is low, and the water resources management is not unified;

⑤ Low water fee can't arouse people's awareness of water saving, and industrial and agricultural water is wasted;

⑥ Environmental pollution greatly reduces the utilization rate of the Yellow River water.

⑦ Excessive sewage discharge from factories along the river.

waterfall

Due to sediment deposition, in most sections of the Yellow River with a total length of 5,464 kilometers, the riverbed is higher than the cities and farmland in the basin, and it is constrained by dikes, so it is called "suspended river". So where did the Yellow River become a "hanging river"?

Dengkou County, southwest of Bayannaoer City, Inner Mongolia, where the Yellow River is 4 to 6 meters higher than the county seat on average.

Valley migration

The Yellow River is the second largest river in China, and it has been a sediment-laden river since ancient times. In the 4th century BC, the lower reaches of the Yellow River were called "turbid rivers" because of its turbid water. /kloc-at the beginning of the 0 th century, it was pointed out that "the river is heavy and turbid, and there are six buckets of mud for one stone". Sediment increased after Tang and Song Dynasties. Some of these sediments are accumulated on the downstream river bed, which is accumulated over time and highly silted, all of which are constrained by dikes and form a suspended river for a long time. In autumn and summer flood season, the defense is weak, ranging from flooding to water diversion. According to historical records, in the three or four thousand years before 1946, the lower Yellow River burst 1593 times, the river changed its course 26 times and burst 1000 times. The flood starts from Haihe River in the north and reaches Huaihe River in the south, covering an area of 250,000 square kilometers, which has a great impact on the geographical environment of the Huang-Huai-Hai Plain in China.

④ 10 century ~ 1 127 (from the end of Tang Dynasty to the end of Northern Song Dynasty)

After nearly a thousand years of accumulation, the lower reaches of the Yellow River gradually silted up from the end of the Tang Dynasty. In 893 (the second year of Tang Jingfu), the estuary section was diverted for nearly a hundred miles. By the fifth generation, the frequency of crevasse increased obviously, with an average of less than three years.

By the beginning of 1 1 century, in today's Shandong Shanghe, Huimin, Binzhou and other cities and counties, the river surface has been "high-rise buildings almost exceeded the height". Since then, the location of the breach has moved up to Ganzhou (now Puyang, Henan) and Huazhou (now East Old Town, hua county). The general trend is that the river swings northward gradually. At the end of the Five Dynasties and the beginning of the Northern Song Dynasty, the Chihe River and the Henglong River were all located in the north of the big river in the Tang Dynasty.

1048, Shang (now Puyang dongchang lake Ji) burst its mouth, and its northward flow passed between Fuyang River and South Canal, while its downstream (now South Canal) and Boundary River (now Haihe River) entered the sea in Tianjin, which was called "Yellow River North School" in history. This is the third major diversion in the history of the Yellow River. (The Yellow River flows northward for three times: Shanghukun, Xiaowukun and Neihuangkou)

⑤1128 ~ 65438+the middle of the 6th century (from Jin Dynasty to Ming Jiajing Wanli)

1 128 (the second year of jianyan in the southern song dynasty), in order to prevent the nomads from going south, Du Chong, who was left behind by Song and Tokyo, was forced to break the river in the southwest of Huaxian County, Henan Province, making the Yellow River flow eastward through northeast Henan and southwest Shandong, enter Surabaya and seize Si into Huaihe River. Since then, the Yellow River has left the old road flowing through Xunhua and slippery areas since the Spring and Autumn Period and the Warring States Period, and no longer entered the Hebei Plain. In the following 700 years, it flowed into the Huaihe River in the southeast. This is an epoch-making event in the history of the changes in the lower reaches of the Yellow River, and it is also the fourth major diversion of the Yellow River.

The river between Jun and Slip used to be a narrow river in the lower reaches of the Yellow River. Due to the control of this section of the waterway, the swing range of the downstream waterway is basically limited to the Hebei Plain east of Taihang Mountain and north of Shandong Hill. After leaving this section of the river, the downstream river turns to the east or southeast and swings from northeast Henan to southwest Shandong. Among the 12 crevasses recorded in the Jin Dynasty, the river swings after the crevasse accounted for 10 in this area.

1286 (23rd year of Zhiyuan) 10 The Yellow River is located in Wu Yuan, Wu Yang, Zhongmou, Yanjin, Kaifeng, Xiangfu, Qixian, Suizhou, Chenliu, Tongxu, Taikang, Weishi, Weichuan, Yanling and Fugou. It can be roughly divided into three strands; One goes south in Zhongmou, passes through Weishi, Weichuan, Fugou, Yanling and other places, and enters the Huaihe River from Shui Ying; One is in Kaifeng, turns south, passes through Tongxu and Taikang, and flows from the vortex to the Huaihe River. We call it the fifth great diversion in the history of the Yellow River.

Recently, the problem of sandstorm has become more and more serious. Now, experts say that if human beings cut down again, the source of the Yellow River is likely to be submerged in sandstorms. The Yellow River is the origin of the Chinese nation, but it is called the source of the mother river. Today, it is surrounded by barren hills and sandstorms everywhere.

Experts pointed out that illegal logging against the natural way of life is the main reason for destroying water resources, which makes this ecosystem with thousands of years of history face collapse and is likely to become another site of human civilization destruction.

It is the frequent flooding of the Yellow River that has created the Chinese nation's character of "being prepared for danger in times of peace". Chinese civilization also began with Dayu's arduous struggle to control water and divert rivers into the sea, so that many dynasties set up river management institutions, and the people of China also set up the "Yellow River Water Conservancy Commission", which is very rare in the world. It can be said that the Yellow River has played a decisive role in shaping the character of the Chinese nation and the direction of Chinese civilization.

[Edit this paragraph] Tourism resources

The vibrant upstream reach-this reach is called the "rich mining area" of the Yellow River's hydraulic resources. Among them, from Longyang Gorge to Qingtongxia, rivers and canyons alternate with each other, with large riverbed gradient and rich hydraulic resources. The planned utilization gap exceeds 1.200m, and the installed capacity exceeds1.0 million kilowatts, accounting for nearly 50% of the whole river. The average annual power generation is nearly 60 billion kWh.

The tender and lingering Ningmeng reach-the Yellow River flows peacefully here, irrigating the farmland on both sides and benefiting the local people. Therefore, there is a saying that "Huang Hefu and Ningxia are the best in the world" and "the Yellow River risks only one side is rich". The land near Yinchuan, Ningxia is flat and has a vast area. For more than 2000 years, the Yellow River has been used for gravity irrigation. There are abundant products here, and the precious Chinese herbal medicines Lycium barbarum and Yinchuan rice are of good quality, which is known as "Jiangbei". Photo of Lycium barbarum The Hetao Plain in Inner Mongolia is very dry. In the west, the annual precipitation is less than 200mm. Here, "no water is a desert, and water is an oasis". The Yellow River water has created superior conditions for industrial and agricultural production here.

The middle reaches of the Yellow River-Shaanxi-Gansu-Ningxia Gorge, where the Yellow River splits the Wan Ren Mountain like a bamboo, forming the longest continuous canyon section on the Yellow River. There are two famous places in this paragraph:

1. Hukou Waterfall-The Yellow River rushed here with thunderous momentum and roared away. Hukou Waterfall is not only a symbol of the Yellow River, but also a symbol of the Chinese nation's indomitable spirit of pioneering and forging ahead. The majestic song "The wind is roaring, the horse is roaring, the Yellow River is roaring, and the Yellow River is roaring" sings the elegance of the Yellow River and the heroic spirit of the Chinese nation's invincible and hard struggle. (The lyrics are selected from The Yellow River Cantata)

First, the second longest river in China.

The Yellow River, the second longest river in China, is a 5464-kilometer-long river that winds in the north of China. Seen from the air, it looks like a huge "Ji", which is a unique totem of our nation-the dragon.

Second, the characterization of the Yellow River

Not just a big river. The Yellow River, Yellow Earth, Emperor, Yellow Skin and the legendary dragon, all these yellow symbols sublimate this turbid stream flowing through the heart of China into a sacred river. Han Shu Gou Ji regards the Yellow River as the first of all waters: "China has the source of all rivers, and the Yellow River is its ancestor."

Fourth, the deep and vast loess layer.

This is an unparalleled loess, with an area of 4 1 1,000 square kilometers, and the thickness of loess coverage is generally above 1 1,000 meters. The loess in Longdong, Shaanxi, Shanxi and other places is as deep as 100 to 200 meters, and the thickness in Lanzhou is more than 300 meters.

Eight, the vegetation on the Loess Plateau suffered great damage for the first time before the unification of the six countries by Emperor Wu of the Han Dynasty, and a large number of people entered Guanzhong, and the cultivated area increased greatly. At the same time, large-scale construction, the construction of the palace mausoleum, wantonly cut down the Guanzhong mountain forest. In the thirty-third year of the First Emperor (2 14 BC), Meng Tian defeated the Xiongnu and gained a large area of land in Hetao. Later, he settled in other places to defend the border and immigrated to the Ordos Plateau many times, with hundreds of thousands of people each time. The originally endless grassland has become a farming area.

Nine, uncover the bottom of the river

A few days ago, a century-old wonder "uncovering the bottom of the river" appeared in Dajinzui and Xiaoshizui sections of Shanxi Hejin section of the Xiaobei main stream of the Yellow River (Shanxi and Shaanxi sections), and the sediment at the bottom of the river was rolled up like a carpet by the current.

The phenomenon of "uncovering the bottom of the river" is a unique law of sediment movement in the Yellow River, which mainly occurs in Longmen, the main stream of Xiaobei, and Weihe, the tributary of the Yellow River. Its performance is that when the flood peak with high sediment concentration passes by, the riverbed is seriously washed in a short time, and the massive and flaky sediment at the bottom of the river is rolled up like a carpet, and then swept away by the current. Such intense scouring can make this section of riverbed several meters to more than ten meters deep in a few hours to dozens of hours. Due to the special conditions of the phenomenon of "uncovering the bottom of the river", "uncovering the bottom of the river" is called the century-old wonder of the Yellow River.

It is reported that the Yellow River was last "uncovered" on July 6, 1977 at/kloc-0. This "river bottom revelation" began at 8: 00 on July 5 and lasted until 8: 40. During this period, in the spur dike section of Xiaoshizui Reconstruction Project 1 in Hejin reach, two large-scale lifting objects 1 with a height of about 1 m and a length of about 7-9 m were hoisted successively with the turbulent underwater sound.

At the beginning of July, the tributaries from Wubao to Longmen in the middle reaches of the Yellow River were flooded with heavy rain, and the flood carried a lot of sediment south. On the evening of July 4th, the flood peak discharge of Longmen Hydrological Station at the source of Hejin reached 4600 cubic meters per second, and the maximum sediment concentration was more than 700 kilograms per cubic meter, which created conditions for the phenomenon of "uncovering the bottom of the river" in some areas.

[Edit this paragraph] Cultural relevance

Yellow river culture