Abstract: The general plan of harnessing the Yellow River is a decision-making subject of the people in China for generations. This paper points out that it is the fundamental solution to reduce the amount of yellow sand flowing into the Yellow River by taking modern engineering measures to rectify the areas with serious soil erosion on the Loess Plateau into scattered relative plains and changing their erosion geographical environment. At the same time, the comprehensive management strategy of water transfer in other basins is put forward. The lower reaches of the Yellow River, as the channel for floods in the upper reaches of Huaihe River and Hanjiang River, increase the flood discharge capacity of the Yellow River, and Xiaolangdi Reservoir can also take the opportunity to discharge sand into the sea.

Keywords: strategic sediment control of the Yellow River

1 Introduction

The Yellow River is of incomparable significance to the Chinese nation, including the Yangtze River. It flows through the hinterland of China and breeds the Chinese nation. The descendants of China not only benefited from the feeding of the Yellow River and the Loess, but also suffered from "good siltation, good determination and good migration" in the lower reaches of the Yellow River. In the history of the survival and development of the Chinese nation, there is a great deal of space related to the management of the Yellow River. In the past dynasties, how to formulate a general plan for the management of the Yellow River was a decision-making topic for Chinese people. The earliest successful example of harnessing the Yellow River, which is highly praised by later generations, is the legendary Dayu. He improved the practice of workers and guns "blocking water" and adopted the strategy of "dredging rivers and guiding stagnation" to quell floods. This legend, in fact, is the summary of the ancestors governing the river [1]. It can be confirmed from the literature records after the Zhou Dynasty that the prototype of the Yellow River flood control levee existed as early as the Spring and Autumn Period and the Warring States Period. After the rise of vassal States, more manpower and material resources can be organized to start from one place, and broken or even beggar-thy-neighbor dikes appear on both sides of the river. Bigger and longer became the early Great Wall of China. It is recorded in writing that at the beginning of Emperor Ai's accession to the throne in the Western Han Dynasty, Jia Rang put forward three strategies for river management, which is another important strategy after Gun and Yu. The problem Jia Jean faced at that time was that the river in the lower reaches of the Yellow River was "higher than the houses" and was already "hanging on the ground". The width of dikes is inconsistent and the layout is more chaotic, so his last proposition is to build dikes to control rivers. Among the three strategies, the best one advocates abandoning the old river course and artificially diverting water to the north. He believes that "this merit, the river will settle the people's safety, and it will not suffer for a thousand years, so it is one of the strategies." Zhongce advocates diverting water into Zhangzhou. "This is a sincere way to enrich the country and strengthen the people, promote the benefits and eliminate the evils, and support the centenarians, so it is called China Policy." Limited by the social and economic conditions at that time, Jia Rang's three strategies were not seriously realized. In the Eastern Han Dynasty, Wang Jing's flood control strategy was implemented on a large scale. He chose a better route for the river, from Xingyang East to Haikou, trekking thousands of miles, building canals and dikes, and using the osawa along the river to discharge silt. He did not achieve great diversion and change, and has always been appreciated by future generations. However, this kind of An Lan is relative after all, with a lot of sediment deposition, at least in the Sui, Tang and Five Dynasties, and there can be no historical fact of "innocent Millennium". Pan Jixun's theory and practice of "attacking sand with water" in Ming Dynasty are worth learning. He advocated "building dikes" on the north and south banks, and tried to improve the dike system, such as using thunder dikes to control water and sand, using remote dikes to suppress floods, and using lattice dikes to promote beach deposition; In order to prevent floods, a rolling dam was built to drain water. At that time, under the condition that the Yellow River went south, we made full use of the water of Huaihe River and used the regulating ability of Hongze Lake to "store and brush the Yellow River". Pan Jixun realized two turning points of river regulation from diversion to confluence and from water control to sand control, and grasped the fundamental problem of sediment deposition in the Yellow River. Obviously, this is very clever. Therefore, after him, most of the river management measures in Ming and Qing Dynasties followed his river management principles. His thoughts and methods of river management have even influenced to this day. However, the Yellow River bed continued to be silted up, and the sediment disaster accumulated day by day, so that at 1855, there was a drastic change in the diversion of the copper tile compartment.

In the past 50 years, great progress has been made in the management and development of the Yellow River, and the Yellow River has begun to become a river that benefits the people. Summarizing the success or failure experience and scientific research achievements of harnessing the Yellow River, it is considered that the sediment problem can be properly solved by taking measures such as blocking, discharging, releasing, regulating, digging and comprehensive harnessing. Taking the policy of "blocking the upper part and discharging the lower part, and separating the two banks" can effectively control the flood. They are organically combined to form an engineering system for flood control and siltation reduction. Obviously, in this way, the Yellow River is taken as a whole to consider the control countermeasures, and people's research and control practice on the Yellow River has entered a brand-new stage. The Yellow River levee, once riddled with holes, has now become a magnificent "Great Wall on Water" and a watershed between Haihe River and Huaihe River. Through people's efforts, the miracle of uninterrupted flood for 52 consecutive years and the fruitful results of comprehensive management and development have been realized, and the achievements in managing the Yellow River are universally recognized. However, the Yellow River is, after all, the most intractable river in the world. Since Dayu's flood control more than 4000 years ago, through the practice of many predecessors, Nilong's wandering temper has never been changed. It is clearly recorded in the history books that the Yellow River overflowed 1500 times and changed its course 26 times in more than 2,600 years. The downstream crevasse flood ranges from Jingu in the north to Jianghuai in the south, with a vertical and horizontal area of 250,000 square kilometers. Frequent breaches and diversions have brought serious disasters to people on both sides of the strait. Nowadays, with the rapid growth of population, the rapid development of economy and the sharp increase of human activity intensity in the Yellow River basin, the hidden worry of the mother river still exists. Because the amount of water washed into the sea is greatly reduced, the downstream riverbed is continuously silted and raised, and the flood discharge capacity is greatly weakened. Before the flood on the high beach surface approaches 1855, the river channel has tended to the early warning height, and the suspended river situation is extremely severe. Seriously threaten the lives and property of people on both sides of the downstream. On the other hand, there is a disaster of seasonal water cuts. In the 27 years since 1972, water supply has been cut off in 2 1 year, especially in the 1990s. It has affected the urban and rural life and industrial and agricultural production water that rely on the Yellow River for water supply, which not only directly caused huge economic losses, but also brought many ecological and environmental problems [2,3], such as the intensification of land salinization in the estuary area, the degradation of estuary wetland ecosystem and the decrease of biodiversity, which made the Yellow River Delta increasingly barren. The cut-off of the Yellow River and the environmental deterioration caused by floods cross each other.

Coupled with the hidden crisis in the An Lan of the Yellow River, the cause of harnessing the Yellow River is extremely arduous and has a long way to go. Especially with the development of national economy and the evolution of the Yellow River, higher requirements are put forward for the management and development of the Yellow River, which makes the management of the Yellow River face many problems. How to make the cause of harnessing the Yellow River more in line with objective natural laws and social and economic laws urgently requires us to continue to explore and struggle. On the basis of predecessors' research and practice, this paper briefly discusses the regulation of the Yellow River.

2 The fundamental reason for reducing the input of yellow sand is policy.

As we all know, the crux of the Yellow River disaster lies in sand, which is caused by serious soil erosion on the Loess Plateau. This area is the residual vein of Qilian Mountain in the west, Helan Mountain in the northwest, Guancen Mountain and Taihang Mountain in the east, Yinshan Mountain in the north and Qinling Mountain in the south. * * * covers an area of 640,000 km2, with an altitude of 1000 ~ 100 ~ 300m and a relative height difference of 1000 ~ 300m. It is the deepest loess cover in the world. Under special boundary conditions, the rainstorm in the middle reaches is the dynamic factor of soil erosion and serious soil erosion in the Loess Plateau. "The steeper the erosion, the steeper the erosion" [4] The Loess Plateau is cut into pieces with ravines. The annual sediment transport in loess hilly and gully region is about 65.438+00 billion tons, which can reach 20,000 t/(a.5 km2) in soil erosion modulus. A large amount of sediment enters the Yellow River, causing some reservoirs to be flooded. Many people think that the Loess Plateau used to be a prosperous place with good vegetation in history, and hope to change the ecological environment of the Loess Plateau by planting trees and grass, so as to achieve the goal of radical cure of the Yellow River. However, we should also realize that the North China Plain shaped by the Yellow River is the center for the Chinese nation to thrive, and the Yellow River was a sandy river as early as ancient times. "Zuo Zhuan" quoted Zhou Shi: "Initiate Heqing, life geometry!" It shows that the Yellow River was quite turbid in earlier times, because the natural phenomenon of sand in the Yellow River should be much earlier than this poem by Zhou. The middle reaches where she flows, especially most of the areas with serious soil erosion defined in modern times, have been the areas with extremely harsh natural conditions and the most serious water erosion and wind erosion since ancient times. This can be proved from The Book of Songs at the Turn of October in Xiaoya: "Ye Ye is surprised by electricity, but uneasy. Hundreds of rivers boil and mountains collapse. The high shore is a valley, and the deep valley is a mausoleum. " This poem vividly depicts the natural landscape of intense soil erosion in the Loess Plateau during flash floods after heavy rains more than 2,000 years ago. Another example is Yu Gong, who said, "Don't bid farewell to the nine continents and dredge the river with the mountains", indicating that the soil erosion in the Loess Plateau was very serious at that time, and a large amount of sediment entered the Yellow River, which made the sedimentation in the lower reaches of the Yellow River increasingly serious, and people had the idea of "dredging the river with the mountains" (that is, dredging the upper reaches of the river with the mountains). Original or conventional production methods are difficult to ensure good site conditions for plant growth, so it is difficult to achieve a certain vegetation coverage [5]. In any case, the influence of natural climate must be considered when estimating the vegetation status in the middle reaches of the ancient Yellow River. The Book of Songs Daya Han Yun describes the drought in Zhou Xuanwang for many years: "The drought is very serious, and abuse is seen in the show, such as? NFDA4？ Such as burning. " In other words, the land is as dry as fire, and the mountains and rivers are dry. Obviously, it is difficult to have good vegetation in such a dry climate.

We believe that for soil and water conservation in the Loess Plateau, we must jump out of the traditional framework and adopt modern engineering measures, such as building controlled sand retaining projects, warping dams and necessary retaining walls to turn gullies into flat land; It also includes artificial directional blasting and other measures to make the towering headland beam fill the ravine and turn the slope into a relatively plain. At the same time, it is supplemented by necessary biological measures. These measures have turned areas with serious soil erosion, after years of management, now only account for about 20% of the total area of the Loess Plateau, and turned them into scattered relative plains. On this "plain" which has lost its erosive geographical environment, soil erosion has been curbed, and the yellow mud and sand flowing into this landform type area can be reduced by 70 ~ 80% (in fact, it is impossible and unnecessary to reduce the yellow mud and sand by 100%, otherwise the downstream river course will suffer from strong erosion, especially bringing great trouble to the estuary delta area).

Only by starting with the most basic watershed units and changing the erosion geographical environment in areas with serious soil erosion through engineering measures is the fundamental solution to the Yellow River, which can never be realized after a long time. As long as it is implemented immediately and step by step, it will take more than 10 years. On these artificial "loess plains" with water conservation conditions, it is not difficult to realize the grand goal of "rebuilding the beautiful northwest region with mountains and rivers" in the near future by taking corresponding biological measures. Judging from the existing technical and economic conditions, this is completely feasible. Facing the 2 1 century, it is also necessary to shift the strategic focus of China's economic development to the west from the perspective of social and ecological environment coordination.

3. Integrated management strategy combined with water transfer in other river basins

According to legend, in ancient China, "the soup was cut by the flood, and Hu Aishan Xiangling was swaying and mighty." However, after vicissitudes of life, the water resources of the Yellow River have been increasingly scarce since modern times, accounting for only 2% of the national river runoff. A large number of data show that water shortage is the main driving factor for the continuous siltation in the lower reaches of the Yellow River, and it is also another crux of the Yellow River. The model test shows that the decrease of flood chance is the main reason for the shrinkage of the lower Yellow River bed and the low flood discharge capacity in recent years [7]. From the point of view of water resources, the Yellow River is the only river with a long history that flows through the arid and water-deficient northwest and north China. The basin has a vast territory, diverse environment and rich land and mineral resources, but its development is restricted by the lack of water resources. Therefore, the Yellow River regulation should not only consider flood control, but also consider water resources. The average runoff depth above Huayuankou for many years is 77mm, which is 28% of the national average runoff depth of 276 mm The serious water shortage in the lower reaches of the Yellow River is a long-term, regional and resource-based water shortage. Therefore, the fundamental measure to alleviate the contradiction between supply and demand of water resources in the lower reaches of the Yellow River is to open sources, that is, to transfer water from other basins to supplement the effective water resources of the Yellow River, which is a long-term strategic measure to adapt to development. Therefore, we can take advantage of the superior geographical position south of the Yellow River.

Basically, along the route of the Middle Route of the South-to-North Water Transfer Project, the water that can be pumped from the upper reaches of the Hanjiang River and Huaihe River is introduced into the Yellow River by itself in the upper reaches of Taohuayu in the west of Zhengzhou (such as near Gubaizui) through Nanyang, Pingdingshan and Xuchang, and is regulated by Dongping Lake and the proposed Taohuayu water conservancy project. Then, through the existing downstream Yellow River Diversion Project, including Yellow River Diversion Project into Tianjin, Yellow River Diversion Project into Hebei (the existing productive Yellow River Diversion Project and Weishan Yellow River Diversion Project have large water supply capacity) and Yellow River Diversion Project into Green, water will be supplied to relevant areas in Henan, Shandong and Hebei, taking into account the water transfer function of the middle route and east route of South-to-North Water Transfer Project. This can alleviate the pressure of supply and demand of water resources in the Yellow River, and achieve the purpose of solving the downstream cut-off, ensuring the water consumption for sediment transport and improving the siltation of downstream rivers. If the scale of water transfer is guaranteed, it can not only alleviate the water shortage in relevant areas of Hebei, but also help Beijing and Tianjin meet the water supply requirements of Beijing and Tianjin in the original Middle Route of South-to-North Water Transfer Project through local adjustment of Hebei water system. On this premise, the water consumption in the middle and upper reaches of the Yellow River basin can be mainly considered, thus alleviating the unfavorable situation of water shortage in the middle and upper reaches of the Yellow River. Xiaolangdi Reservoir can transfer water to the north according to the principle of "high water and high utilization".

When transferring water from Danjiangkou Reservoir to the Yellow River, the main canal along the way should be flush with the rivers and catchment areas in Huaihe River Basin, and combined with the flood control system in this basin to form a "series reservoir", which can not only play a corresponding role in water supply, but also produce other huge social and economic benefits, especially in the rainstorm period of Huaihe River and Hanjiang River Basin. First, by optimizing the operation, the unbearable flood volume of Huaihe River and Hanjiang River Basin will be transferred to the Yellow River, and the lower reaches of the Yellow River will be used as the main tributary of the upper reaches of Huaihe River, thus greatly reducing the flood control pressure of Huaihe River and Hanjiang River. Secondly, flood diversion into the Yellow River can scour the lower reaches of the Yellow River, expand the cross-sectional area of the main channel, improve flood discharge capacity and reduce downstream siltation. The research results of experts such as Zhao Yean [8] and the model test data we conducted [7] show that there is a law of "big water and big sediment" and "big water and good river" in the lower reaches of the Yellow River, and the lack of water and sediment is the fundamental reason for siltation in the lower reaches of the Yellow River, and the disharmony between water and sediment is another main reason for the intensification of siltation in the lower reaches of the Yellow River. Therefore [9], only by introducing flood into the Yellow River and making the flow rate adapt to the sediment concentration can we achieve the best effect of sediment transport and siltation reduction. Third, the storage capacity of Xiaolangdi Reservoir is the guarantee of comprehensive utilization benefit [10]. Xiaolangdi Reservoir can use flood diversion to concentrate sediment discharge, and use large water to discharge sediment into the sea, which correspondingly increases the extremely valuable storage capacity of the reservoir. The regulation capacity of the reservoir is increased, and the comprehensive utilization benefit of the reservoir is greatly improved.

In a word, such water transfer can produce great benefits for flood control and siltation reduction of the Yellow River and even the whole Yellow River, and is of great significance for improving the ecological environment in the lower reaches of the Yellow River, especially in the delta region. A large amount of sediment is reclaimed from the sea to make land, and the land area of the estuary delta is continuously expanded, which is beneficial to the conversion of local offshore oil into land exploitation, and has far-reaching significance.

In order to make up for the water consumption of the lower reaches of the Han River in the dry season, the project of diverting water from the Yangtze River to the Han River can be built, that is, transferring water from the vicinity of Shashi in Jingjiang to the lower reaches of the Han River. In order to save the length of the river and facilitate water storage, the project of diverting water from the Yangtze River to the Han River can pass through the long lake. Initially choose Shayang Town as the mouth of the Han River, which is located in the upper reaches of Xinglong Hub, one of the planning steps, and is convenient for regulation. The average runoff of Jingjiang River for many years is large and stable, and the flood season is as long as half a year, which ensures that water transfer can replenish the Han River and reduce the flood control pressure of Jingjiang River in flood season.

4 conclusion

In view of the crux of "less water and more sand", we must scientifically formulate the general plan for harnessing the Yellow River. In order to greatly reduce the amount of yellow sand flowing into the Loess Plateau, modern engineering measures should be taken to rectify the areas with serious soil erosion into scattered relative plains and change their erosion geographical environment. This radical solution is undoubtedly effective.

In order to alleviate the contradiction between supply and demand of water resources in the Yellow River basin, especially in the downstream areas, water should be transferred from the upper reaches of the Han River and Huaihe River to the Yellow River, and sediment should be washed and silted to improve the ecological environment, taking into account the water supply function of the middle route and the eastern route of the South-to-North Water Transfer Project, and taking the lower reaches of the Yellow River as the flood passage of the Huaihe River and the upper reaches of the Han River, expanding the section of the lower reaches of the Yellow River, and taking the opportunity to transport the sediment discharged from Xiaolangdi Reservoir into the sea to improve the comprehensive benefits of the reservoir.

The general plan of harnessing the Yellow River put forward in this paper not only studies the harnessing countermeasures of the Yellow River as a whole, but also considers the adjacent river basins as a system and the flood control and water use issues as a whole, so as to optimize the allocation of water resources in the Huang-Huai-Hai Plain to the maximum extent.

refer to

[1] Xie Jianheng, Zhao Wenlin. History and present situation of sediment problems in the yellow river. Sediments in the Yellow River. Editor-in-Chief Zhao Wenlin. Yellow river water conservancy press, 1996.

[2] Zhang Junhua, Zhang Hongwu, Chen Shukui and so on. Influence, causes and countermeasures of cutoff in the lower yellow river. See: Technical Progress of Water Conservancy and Hydropower Engineering in China. Editor-in-chief Shao Weiwen. Beijing: Ocean Press, 1999.

[3] Yao, Zhao Yean, etc. Preliminary study on cutoff of the lower yellow river. Advances in water science, 1999, (2).

[4] Xie Jiaze. On harnessing the lower reaches of the yellow river. Collection of Xie Jiaze's works. Beijing: China Science and Technology Press, 1995.

[5] Zhang Hongwu. Countermeasures for the yellow river problem. Science Times, 1999.3.24.

[6] Zhang Hongwu, Yao,. Radical treatment of the Yellow River is not a dream. Science and technology daily, 1997.

[7] Zhang Hongwu, et al. Similarity law of flood model with high sediment concentration in the Yellow River. Zhengzhou: Henan Science and Technology Press, 1994.

[8] Zhao Yean, Pan Xiandi, etc. Scouring and silting in the lower reaches of the yellow river and its basic laws. See: Collection of Scientific Research Papers of Yellow River Water Conservancy Research Institute. (episode I, sediment and soil conservation). Henan Science and Technology Press, 1989.

[9] Zhao Yean, Pan Xiandi. Strategic position of sediment research in Yellow River regulation and development. Sediments in the Yellow River. Editor-in-Chief Zhao Wenlin. Yellow river water conservancy press, 1996.

[10] Zhang Junhua, Zhang Hongwu. Study on siltation and downstream siltation reduction in Xiaolangdi reservoir area. See: Technical Progress of Water Conservancy and Hydropower Engineering in China. Editor-in-chief Shao Weiwen. Beijing: Ocean Press, 1999.