My Retrospect and Prospect for Managing the Yellow River

I was born in Liuxiayu Village, North of Changxindian in the City of Beijing, 1942. In 1963 I began working at the Sediment Research Division, China Institute of Water Resources and Hydropower, when I first exposed to the sediment issues of the rivers. It has been 47 years since that time. In retrospect, I deeply feel that Yellow River is not the same river as it was 50 years ago. The understanding of it should not be the same as 50 years ago, nor should the management strategies. Discovering the natural hybrid rice by Mr. Longping Yuan lead to a revolutionary of rice, but the discovery of the formation of Beiluohe River channel didn’t promote the revolution of the management of Yellow River.

1. Inspiration from the Formation of Beiluohe River’s Channel

In the 1970’s I participated in the second-round design of the Yellow River, and we investigated the Sanmenxia Reservoir. At the end of the backwater, I discovered the lower reach of Beiluohe River flowing into the reservoir has a narrow, deep and stable channel, just like a man-made wandering canal, which gave me great impression. When I asked this question, Prof Ning Qian meditated for a while, and then said “high sediment concentrations”. In the following years, I analyzed the research results from previous studies, and found the incoming flow and sediment, the channel evolutionary characteristics of Beihuohe River and Weihe River. There were frequent floods of Beiluohe River with sediment concentration around 700-900 kg/m3. The narrow and deep channel was shaped by the flood, and great amount of sediment can be transported over several hundred kilometers reach with strong scour on the main channel. The sediment transport characteristics of Weihe and Beiluohe’s channel have greater similarity with that of the hyperconcentrated flow in the canals and pipelines. For the muddy flow in pipelines, just like the sediment size distribution of hyperconcentrated flow with particles smaller than 0.08 mm in diameters, can all be treated as gravity media. As long as the resistance force can be overcome, the particle can be transported without considering the sediment carrying capacities. Through the analysis of field-observed hyperconcentrated flow data collected from different reaches along the main stem and major tributaries of the Yellow River, the conclusion can be drawn that narrow and deep channel is suitable for transporting hyperconcentrated flow. The suitable sediment concentration is not low concentration, and the main reason for sediment deposition along the lower Yellow River is because of the shallow and wide channels. When the majority of the sediment of a river is transported by hyperconcentrated flood, a narrow and deep wandering channel can be developed. The Sediment Research Commission of Chinese Water Resources Society paid great interests in the result of my research, and recommended it to Journal of Hydraulic Research. Finally a journal paper entitled “Sediment Transport Characteristics of Hyperconcentrated Flow and the Formation of Its Bed of Yellow River” published in Volume 8, 1982. In the following days, centered around the impact of hyperconcentrated flow on flood protection, I researched the abnormal phenomena due the strong adjustment of the river bed during the transport process of hyperconcentrated flow on wandering channel, how the “muddy river” is developed, and why flood peak discharge increases along the river. All those research results, can not only answer the questions of flood protection issues in reality, but also consolidate the understanding of the transport characteristics of hyperconcentrated flow.

In order to manage the wandering river channel that is not suitable for sediment transport, in-depth analysis were carried out to study the principle of channel adjustment under different incoming sediment and flow condition, and the phenomena that fine sediment particle is easy to suspend due to the steep slope of the wandering channel. Under such condition, channel adjustment is interrelated and influenced, but the shallow and wide shape is kept. Even with the slope change after siltation, sediment transport capacity doesn’t increase and the equilibrium condition cannot be achieved. On the contrary, the vicious cycles were created, and the evolution characteristics are just like an unstable channel with no drop structure built. Only the narrow and deep river can form a stable wandering channel. These research results were published entitled “Formation of the Wandering Channel of Yellow River and the Transformation Approach” in Journal of Sediment Research in Volume 4, 1989.

2. The Attentions from Academia Prompt the Development of Further Research

The preliminary research results drew attentions from the academia. As early as in 1987, during the Sino-America Symposium on Yellow River Research, member of the Chinese Academy of Science, Mr. Bingwei Huang (1913-2000) pointed out “Among various strategies, using the properties of hyperconcentrated flow to transport sediment to sea and eliminate the sediment deposition on the channel bed of lower reach, might be an effective technical measure.” “If we were sure that hyperconcentrated flow cannot be used for sediment transport now, I do want to know the reason to reject it.”

Based on the reaction from the academia, from 1989 to 1991, Dr Zhaohui Wan led the National Science Foundation funded project entitled “Principles for the Dynamics of Hyperconcentrated Flow and Prospects of Its Application in the Yellow River”, which included the latest research results from Tsinghua University, China Institute of Water Resources and Hydropower and Yellow River Institute of Hydraulic Research. The rheological properties of hyperconcentrated flow, dynamic and sediment transport characteristics, and prospects of its application on the Yellow River. Prefaced by Mme. Zhengying Qian and Mr. Bingwei Huang, members of Chinese Academy of Science and Engineering respectively, the results from this project were published, with their sincere hope on the research of the hyperconcentrated flow. The history of flood hazard of lower Yellow River will never happens today as it was in history. By regulating Xiaolangdi Reservoir, the management of the Yellow River can be achieved through developing a suitable water and sediment condition that sediment is mainly transported by hyperconcentrated flow.

In 1998, during the concluding speeches in the Symposium on Managing the Lower Yellow River, Mme. Zhengying Qian thought the idea of using narrow and deep channel to transport hyperconcentrated flow is a great breakthrough, and hoped it can be reflected in the long term river plans. Under her urges, making full use of the sediment transport characteristics of hyperconcentrated flow to resolve the siltation issue of the lower Yellow River, was listed in the research topics of the Eighth Five Year Plan. This research project was led by me, and it was in collaboration with Yellow River Institute of Hydraulic Research, Yellow River Planning and Design Institute, Tsinghua University and China Institute of Water Resources and Hydropower. Through three years of hard work, this research project was successfully completed. The research results were published officially in a book entitled “Research on the Change of Water and Sediment in the Yellow River and the Measures to Reduce the Siltation in the Lower Reach” by Yellow River Water Resources Publishing Co. Ltd. This book was the first one to propose new flood protection function of Xiaolangdi Reservoir, which is sediment discharge by flood instead of eliminating hyperconcentrated flow. This operational method of this reservoir is also changed from the traditional “store the clear water during non-flood season, and discharge muddy water during flood season” to “regulate sediment on a multi-year basis, and discharge it at the right time.” It clearly indicated that during dry years the sediment should not be discharged to downstream, and the reservoir should be operated by the maximum benefit mode. The calculation results also showed, the benefit of using this method will be greatly increased and the water demand for sediment transport can also be reduced by 2/3, with an average annual demand of only 6 billion m3. The sediment discharge will be arranged only during the flood season in wet year when Xiaolangdi Reservoir cannot be regulated. 

The research results also drew many attentions from the famous scientists. In 1996, 10 members from Chinese Academic of Science or Engineering, namely Kai Yan, Guoren Dou, Binnan Lin, Qianqing Xu, Jiazheng Pan, Bingwei Huang, Dongsheng Liu, Wenxi Huang, Shupeng Chen, Yueding Li, with nine other experts in water resources fields, presented my research results to Premier Mr. Peng Li by  Mr. Zhenhuai Yang, former Minister, Ministry of Water Resources. They suggested future collaboration research, and include this in the research topics of the “Ninth Five Year Plan”.  However, due to different opinions from other people, it was not successful. But the General Planning Institute, Ministry of Water Resources still provided funding for my research, which made further exploration possible.

3. Formation of the Wandering Reach of the Lower Yellow River and River Training Method

After the Xiaolangdi Reservoir was operated, clear water was released at the early stage. Based on the experiences gained from Sanmenxia Reservoir, clear water scour results the collapses of banks and widens of river, which is not suitable for transporting sediment released by reservoir in channel. During the initial stage of the sediment release from the reservoir based on multi-year sediment regulation, in order to shape the narrow and deep channel, lots of depositions will occur, and the reduction of siltation is not as obvious as water saved for sediment transport. In the long run, if the suitable narrow and deep channel can be formed through river training, not only the siltation can be reduced, but also the flood protection issues of shallow and wide channel can also been resolved. So the research on new river training method for the wandering reach began.

The research on the wandering reach of the lower Yellow River shows, the strong deposition on the main channel results in a lower main channel but a higher floodplain, which keeps the main channel moves frequently, and it is not good for flood protection. After Sanmenxia Reservoir was operated as “store clear water and discharge muddy water”, the effect of small discharge resulting siltation in the channel will decrease. With the control of the river training project, the river channel gradually becomes stable. Although it has positive impact on flood protection, without the fundamental change of incoming flow and sediment for the wandering reach, it also controls the location of sediment deposition, and changes the evolutionary principles that the natural river will shift to balance the elevation differences between the main channel and the floodplain, and results in the increase of the main channel becomes faster than the increase of the floodplain. This is the main reason for the “Secondary Suspended River”, and the situation becomes worse with the contribution from the production dykes, creating new threats for flood protection. Shallow and wide channels are also the main obstacles for transporting sediment to sea by using channel itself.

The major training task for wandering reach is to stable the main channel, and develop the flood discharge and sediment transport corridor. The idea of using “minor curves” to train the wide reach thinks, since the flow line always follows a curvature path, and river training should be based on this rule to stabilize the channel. This idea is based on the training experiences gained from the transition reach downstream of Gaocun. However, the successful example of Gaocun is due to the channel geometry, a narrow and deep channel, not due to the horizontal curvature. To develop a narrow and deep channel through two-bank training is based on the stochastic characteristics of the channel evolution, the adjustment for the channel bed is developing towards the vicious circle. The “minor curve” training method cannot control the river regime to develop a narrow and deep channel. Narrow the channels can only reduce losses due to the inundation on the floodplain, while two-bank training can develop an efficient flood discharge and sediment transport corridor, and control the bed elevation not to increase.

4． Unsteady Features of Flood and Understanding the Principle of “Scour during Rising of a Flood, and Deposit during Falling of a Flood”

Based on multi-year’s research on the dynamics of sediments in the Yellow River, it should be noted that the mechanics behind the phenomena need to be figured out. Since only by understanding the process and the reason of this phenomenon, the knowledge of the Yellow River can really be obtained.  Take the “Deposit on the floodplain while sour the main channel” as an example, after a big flood, there are significant depositions on the floodplain, while there are strong scours in the main channel. From the appearance, they have close relationship, but after the sour process in the channel, it is found that the scour always happens during the rising of a flood. During the falling of a flood, no matter the high or low concentration, there is always deposition on the main channel, even when there are 10 time differences in the channel slopes. From this perspective, the hypothesis of channel scours due to the return of the clear overtopping flow is not true. But how could this happen? It cannot be explained based on the outdated theory of steady flow and single-valued relationship of sediment carrying capacity. From the reality of the Yellow River, we should first learn the theory that narrow and deep channel has the characteristics of “the more sediment input, the more sediment output” (Please refer to Journal of Sediment Research, No.2, 1994). The former director of Institute of Sediment Research, Mr. Lianzhen Ding read this paper and wrote me a letter, and suggested it be published in the Internal Journal of Sediment Research (in English) he edited. With the help of Translation into English, this paper was finally published in No.2, 1995 of this journal. Based on the theory, correct understanding can be obtained with the analysis of the unsteady feature of the flood, as well as the relationship between the change of the forces on the channel bed, and the scour and deposition of the channel. It took us almost 10 years to research on this complex problem, before the research results were published in Journal of Hydraulics, No.6, 2005.

The unsteady feature of the sediment transport by flood, and the understanding of the theory of “Scour during rising of a flood while siltation during falling of a flood”, opens the new path of harnessing the lower reach of the Yellow River. We finally understand that why the rivers with either high or low sediment concentrations, steep or mild slopes, will always be scoured during rising of a flood, and silt during the falling of a flood. With the progress of the understanding this feature, the principles of flood discharge of narrow and deep channels, no-defined relationships between silt on the floodplain while scour on the main channel, long distance sediment transport by flood, regulation of sediment release from reservoir have been greatly advanced. Based on the new understanding, we proposed “non-river bed aggredations” should be set as the strategic aim of harnessing the lower Yellow River.

  

5. The Difficulties of Applying the Scientific Concept of Development

At the early stage when a new academic theory emerges, there are always strong objections from the traditional opinions, which is perfectly normal for the development of science. Mr. Zhaozhong Ding once said, the development of science always follows a rule that the majority of people will agree with minority of people. When new ideas emerge, it is common to have disputes, and it is also normal that most people will object to them. It is a difficult thing to change the traditional opinions.

Faced with a complex river like the Yellow River, it is natural to have debates in understandings. The debates between different academic theories are the motives for the development of science. We wrote letters to related leaders many times and provided our suggestions. For example, we wrote more than ten suggestion letters to Planning and Strategy Research Center, General Institute of Water Resources Planning, entitled “How to Harness the Lower Yellow River Channel” to be included in the Water Resources Analysis and Research Report in China. However, the research results have not drawn sufficient attentions from the administrative agencies.

For the ideas of harnessing the Yellow River in 21st Century, Ministry of Water Resources proposed overall management objectives for the Yellow River: “no embankment breaching, no river course running dry, no pollution over standard and no river bed rising”. Among them, the most difficult one will be “no river bed rising”. Former Minister of Ministry of Water Resources, Mr. Shucheng Wang paid great attentions to our research results. In 2001 when Yellow River Conservancy Commission analyzed the new idea of harnessing the Yellow River in the 21st century, I was appointed as the member of the writing group by luck. The functions of narrow and deep channel in harnessing the lower reach have already been included in the preliminary report, but not in the final formal report of New Management Ideas of 21st Century. In 2005, the agreement on how to manage the lower reach after the operation of Xiaolangdi Reservoir has been reached between Prof Ye’an Zhao, me and Commissioner Mr. Guoying Li. After the meeting, the minutes were documented on developing the main channel suitable for flood discharge and sediment transport, so that the highest efficiency of sediment transport can be realized. But no follow-up happened. In 2008, I reported this issue to Vise Minister Mr. Yong Jiao who’s in charge of planning. He agreed to prompt this idea by select a wide reach, and carry out experiments on two-bank training as a pilot case study.  He has talked with the directors from Yellow River Conservancy Commission, but nothing happened afterwards, which made us dwell a lot.

Member of Chinese Academy of Science, Mr. Jiazheng Pan once said, “Any new idea, as long as it’s named new, means it lacks practical experiences, and there is certain uncertainty involved. The impact of whether a water conservancy project is success is huge. How to secure the project while promoting new technologies becomes a controversial issue. As a vivid example, it’s like who’s going to be the first person to eat crab. In my opinion, there are two methods to resolve this. The first point is to emphasize both “Caution” and “Active” as the basic rules, and either one of them can be neglected. “Caution” means to keep a clear mind, never do anything that has no solid foundation, or there is uncertainty involved. Everything should be experimented and based on the results obtained; the conclusion and decision can thus be made. Especially for the curial projects or part, we can never be careless. “Active” means from our minds, we should believe the innovation and development should be the right way on earth. We should warmly welcome new things with faithful hearts, and conduct in-depth analysis, and create everything we can to ensure their mature and feasibility. We should have the courage to be the first in the world, and not the passive wait, “wait until someone else try it first”. The second point, from the strategy, we should emphasize “seek truth from facts, and treat differently”. (Taken from Pan’s book entitled “The Philosophies in the Constructions of Water Conservancy Projects”.)

6. The Prospects of Harnessing the Lower Yellow River Are Broad, But There Is A Long Way to Go with Huge Responsibilities.

The famous expert on sediment research, Prof. Ning Qian (1922-1986) initialized new research areas of studying hyperconcentrated flow. The famous expert on managing rivers, Prof. Zongdai Fang (1911-1991) first proposed to harness the lower Yellow River by using hyperconcentrated flow. As the student of them, based on the practices gained from the reality closely, I concluded the experiences of their successes and failures. By tracking the changes of flow and sediment in the Yellow River, based on the sediment transport characteristics of hyperconcentrated flow, I proposed a whole new method to overcome the sediment problems of the lower Yellow River, and develop and use the water resources properly. I also sincerely hope that the decision should be made promptly to apply the research on hyperconcentrated flow resulting from generations of scholars in the real engineering practices, which can contribute to the management and development of the Yellow River.

The rivers in North China are turning into dry rivers gradually, with very few floods occurred. The Yellow River watershed is also located in semi-arid region. With the construction of reservoirs, soil and water conservation project, and the development of irrigation, the field observed discharges of the flood also reduced significantly.

Due the combined operations of Longyangxia Reservoir and Liujiaxia Reservoir, and the increase demands from industrial and agricultural uses, the incoming flow can reduce as much as 10 billion m3 during the flood season in a wet year. With the reduction of flow peaks, the bed shaping function has been weakened, which results in more and more conflicts between less water and more sediment. The trend for significantly reduced possibilities of flood occurrence is irreversible. But the flow and sediment condition entering the low reach can be regulated through Xiaolangdi Reservoir on a multi-year basis, and it can be optimized by using sediment release by flood. This also creates condition for making full use of the powerful flood discharge and sediment transport capacities of the narrow and deep channel.

Operation rules, known as “Store clear water and release muddy water” of Sanmenxia Reservoir avoid the sediment deposition on the main channel with small discharges during non-flood season. This operation rules was implemented since 1973, by using the reservoir capacity to regulation sediment downstream of Tongguan, although there were occasions that sediment was released with small discharges, the siltation is still reduced for the channel of the lower Yellow River. River channel upstream of Huayuankou is basically non-aggradated. Xiaolangdi Reservoir is also operated on a multi-year basis, based on the theory that more sediment will be transported during flood seasons. The water resources of Yellow River can be fully used, and better conditions are created for training the wandering reaches. The solid scientific support of the comprehensive sediment management methods like “block, discharge, regulate, release and dredge”, while “regulate” is the key component, is also provided for developing the narrow and deep channel of the lower reach. Sediment release due to the empty of reservoir, and the collapse of sediment deposition which can be reused for a long time, create better incoming flow and sediment condition to ensure the long term non-aggradations of the lower Yellow River channel.

After the operation of Xiaolangdi Reservoir, due to the optimal operation rules, river channels in Henan and Shandong Provinces have all been scoured. In Henan, the scour depth is about 1.8 meters. In Shandong, the sour depth is 1 meter. The total amount of scoured sediment reached 1.3 billion tons.

Through the multi-year sediment regulations of Xiaolangdi Reservoir, the sediment is regulated to be transported by flood. By using this method, the goal of non-rising of the main channel can be achieved or even decrease. The reason is when the hyperconcentrated flow occurs; the main channel is always scoured. During the initial stage of Xiaolangdi Reservoir when clear water is released, after the sediment deposition volume is all filled up, the multi-year sediment regulation rule will be implemented. The sediment is regulated to be released during flood. By using both methods, most of the channel bed will not be raised.

The increase of flow capacity of the main channel will reduce the opportunity of the flood overtopping onto the floodplain, which can make a harmony relationship between the people living in the floodplain with the nature. 1.8 million people living in the floodplain can be totally free of worries, and 3.59 million mu of farmland can be fully utilized. This is the objective request from people-oriented, scientific development point of view for managing the lower Yellow River.

After the operation of Sanmenxia Reservoir, the regulation rules already been in effect which achieve non-aggradations of river bed upstream of Huayuankou (The floodplain of Meng County and Wen County has already been turned into residential areas for reservoir resettlement. The multi-year sediment regulations of Xiaolangdi Reservoir, and sediment release by using flood can achieve the non-deposition of channel upstream of Gaocun, or even Aishan. The major issues of the secondary suspended river and management of floodplain can be resolved. The management plan proposed by Mme. Zhengying Qian of  using a narrow channel can also be realized reach by reach.

Scientific development view has already become the major national policy. The innovation of technology should be strengthened, which can turn fruits of science and technology to realistic prolificacy. But until now, the administrative agencies still don’t recognize the huge flood discharge and sediment transport capacity of narrow and deep channel, and they don’t pay much attention to the feasibility of its application in harnessing the Yellow River.

Members of Chinese Academy of Science, Mr. Jiazheng Pan once pointed out in his suggestions on managing the Yellow River: “Scientifically regulating flow and sediment can better shape the downstream channel, and more sediment that enters into lower reach can be transported to sea.” The existence of production dykes already made the lower Yellow River channel as a “narrow channel”. The most pressing matter of the present, should be including the two-bank training strategy which aims at developing a stable, narrow and deep channel, in the long term plans of harnessing the lower Yellow River, and promoting this strategy vigorously. By doing this, we can prove the science and technology are primary productive forces, and it can have an irreplaceable effect on managing and developing the Yellow River. The dreams from various people who care about harnessing this river can be realized soon.

7. My Declaration

The publication of this book is the public reply for various people who wish the research results from hyperconcentrated flow can be applied on managing the Yellow River. The author of this book has devoted unremitting efforts during his lifetime in this research, and all the related issues have been resolved. However, I cannot contend the change in the reality of this society!

1. The strong objections from the traditional researchers of the Yellow River

In regards to our river management strategy, people who are not favorable of it has similar characteristics, that is, they objected not from the technical point of view, like whether or not the channel has the huge capacity of flood discharge and sediment transport? They based their objections emotionally, like the argument “When Pangu created this world, the river is a wide river, so there is no need to change it to a narrow one today”. When the leaders of Ministry of Water Resources wanted to carry out the experiment using my idea on the lower Yellow River, someone said things like, “We cannot allow this experiment, since we do not want to give him chance.”, “Even if we were wrong, we won’t change our plan.”, “Are we all wrong?”, Since the wide river plan can attract more funding. Traditional researchers do not want to recognize the sediment transport potentials of the channels in the lower Yellow River. If they do accept this idea, the whole river training plans need to be changed. One person who is objected to my idea once announced publicly, “If what you said is all true, 5000 years history of harnessing the lower Yellow River will be rewritten. If the huge flood discharge and sediment transport characteristics of the narrow and deep channel is recognized, the famous saying of “less water but more sediment in the lower Yellow River will not be true anymore”, which will weaken the theoretical foundations of traditional management strategy!

2. There are no long term objectives for planning the Yellow River

Under the thinking that “nothing has been understood of the Yellow River”, there are no best solutions, and “it’s difficult to manage this river” becomes a very good excuse. In 2000, Yellow River Conservancy Commission proposed a 500 billion RMB budget on important issues of the Yellow River. Members of Chinese Academy of Engineering, Mme Zhengying Qian, commented on this budget, “the thinking is not clear, and there is no operability.” This time the budget of planning of Yellow River reaches to 900 billion RMB, but there is still no clear management objective. In fact, it appears more like attracting funding. Following Mr. Jiazheng Pan’s suggestions, Chapter 20 was added in the planning document, but there is no change for the previous 19 chapters, which cannot be used to achieve the goals prescribed in the 20th chapter. There are contradictories on regulating water and sediment in the middle reach, but harnessing lower Yellow River as a wide river and storing sediment on the floodplain. The economic society is the outside condition for why the issue above occurs.

3. Drawbacks of the current design and research

From the realistic benefits, deign institutes only concern about if they could win big investment for a project. Regardless of the design method, the payment is based on certain percentage of the overall investment. The design institutes only worries about if they could be paid a full salary to their employee including benefits, and they are busy with launching projects. For many years, it is the reason that nobody is interested in discussing this issue seriously. Research and design institutes are only responsible for the owner of the project, but lack the spirits of being responsible for people. Even there is something wrong, they don’t investigate into the details. It won’t be easy for us to change the money-oriented society today.

4. The application of the research results is extremely difficult.

Everyone wants to contribute to harnessing the Yellow River, so they will feel uncomfortable about new ideas and achievements proposed by other people. For instance, the non-project based river managers thought our research is a monstrous crime. Even after the acceptance from the reviewers, my research paper was rejected by the acting editor based on the following reason, “The practices of managing rivers in 20th century have demonstrated that to radically remove the river related hazard, is not economic, unnecessary, and even impossible. Trying to pursue the objective of radically remove the river related hazard is even harmful.” Our research is fully based on measured data collected along Yellow River, so we do want our opponents to show their realistic proofs.

For such a complicated river like the Yellow River, it is natural to have different opinions. The debate between different opinions will motive the development of science. We should organize an active academic discussion. However currently there are few discussions in journals. Journal of Hydraulic Research is the technical journal published by Chinese Association of Hydraulic Engineers, and it should become the academic media which allows a hundred schools of thought to strive. Once I told the editor-in-chief, Mr. Bingxin Chen, “Whoever has different opinions about my paper, please let him published in this journal, and we welcome such suggestions. If your paper got some issues, and other person is willing to help you revise it, we should be appreciated for their assistance.”

During the symposium on “Wide River or Narrow River”, in front of hundreds of audiences, I have also declared that “on my personal website, there are numerous technical papers of my research.  I sincerely wish the young generations to find flaws in any fundamental theory in these papers. I have a monthly salary of several thousand RMB after retirement, which can be used as the bonus. However, eight months passé,d and no one can claim the bonus.

5. The hope for the solution still exists.

Based on the research findings of my paper, only the respected senior level of researchers can express their attitude. However, suggestions given by those experts do not draw enough attentions from the river management administrations. No solutions can be offered to solve the above issues in our society yet.

It is true that Mr. Guanhua Xu once said, “when faced with debates, opportunity and risk, waiting is never the best solution. The government should take full responsibilities and make the decision with audacity. It all depends on whether the leader is willing to have their determination, their capability and their guts to make those decisions. For the current merchandise prevailed society, the decisions from the upper administrations appear to be more important.

Member of Chinese Academy of Science, Mr. Bingwei Huang wrote the following in the preface of my book published in 1993. “I am 80 years old, and I don’t have many days left in my life. But I still hope before I die, I will witness the water and soil conservation and hyperconcentrated flow research can really contribute to eliminate river hazards radically, and people can enjoy the peaceful life forever.  Flood hazards will not happen today as it was in the history. People of Central China will have happy lives ever since, and our ancestors who worked diligently on managing the Yellow River throughout years will be pleased to rest in peace. I am a senior citizen who’s close to seventy years old, and will soon leave the earth to go to heaven. Now I have the same feeling as Mr. Huang.

Serious research on sediment transport by using the characteristics of hyperconcentrated flow to reduce the siltation on the lower Yellow River channel have been conducted for forty years. A whole new plan of harnessing the Yellow River has been proposed. The administrative leaders should pay attention to the result from this research. I sincerely wish the early application of my research on the Yellow River.

The spirit is willing, but the flesh is weak. I cannot turn the expectations from eight perishing members of Chinese Academy of Science and Chinese Academy of Engineering, as well as other senior scientists who care about harnessing the river, into practices. I really hope in the future, people with lofty ideas will fulfill my unaccomplished historical task.

By Pu Qi

August, 2010.

Management Strategies of Harnessing and Exploiting the Yellow River

The harnessing of the Yellow River has always been a major issue concerning China’s prosperity and people’s peaceful life. From the end of 1998, the Yellow River Conservancy Commission, under the leadership of the Ministry of Water Resources, and in light of the Central Party Committee and the State Council’s call to accelerate the harnessing of great rivers and lakes, combined the great-development-of-the-west strategy with the actual conditions of the Yellow River and began to organize the units concerned to draw up Important Issues of the Yellow River and the Countermeasures and Proposals on Accelerating the Harnessing and Exploiting of the Yellow River. These two reports which were submitted to the State Council covered the following major problems: the serious menace of flood, the gap between water supply and demand, water and soil losses, the deterioration of water environment. According to the spirit of the 116^th meeting of the State Council, the Short-term Programming on the Harnessing and Exploiting the Yellow River was compiled. In July, 2002, the State Council gave a written reply and agreed in principle the Short-term Programming on the Harnessing and Exploiting the Yellow River and required that it must be implemented earnestly.

The major content of the Short-term Programming on the Harnessing and Exploiting the Yellow River includes the general introduction to the basin and its features; the present situation and existing problems; the guiding principle and the goal of the planning; the focal points in the harnessing and exploiting in the near future and the measures.

Ⅰ. The general introduction to the basin and its features

The Yellow River is the second longest river in China which originates from the Yueguzonglie basin and lies in the North of the Bayankala Mountain in the Qingzang Plateau. It flows through 9 provinces like Qinghai, Sichuan, Gansu, Ningxia, Inner Mongolia, Shaanxi, Shanxi, and Shandong, and empties into the Bohai Sea in Kenli County in Shandong Province. The trunk is 5,464 kilometers long, and the basin area is 795,000 square kilometers. Different from other rivers, the area of the upper and middle reaches of the Yellow River Basin account for 95 per cent of its total drainage area. The west area belongs to the Qingzang Plateau, with an altitude of over 3,000 meters; and most of the middle area belongs to the Loess Plateau, with an altitude of 1,000 to 2,000 meters; and the east of the basin belongs to the Huanghuaihai Plain, and the river channel hangs over the ground of the river bank, also the menace of the flood is very serious.

The Yellow River has the following distinct traits different from other rivers:

1. Less water and more sand, water and sand from different origins.

The average natural runoff of the Yellow River over many years is 58 billion m³, and the basin area takes up 8.3 percent of the total land area of China, while the annual runoff only occupies 2 percent of that of the country. In the basin the water volume per capita is 527m³, which accounts for 22 percent of the average level of the country. Mean water for cultivable land is 294m³ per mu, which only occupies 16 percent of the average level of the country. And the demand by the outer part of the basin makes the water per capita even less. Mean annual sediment yield is 1.6 billion tons, mean annual sediment content is 35 kg/m³, all these are regarded as the largest in the world. About 50 percent of water yield comes from above Lanzhou and 90 percent of sediment from the area between Hekou and Sanmenxia.

2. The unique channel shape

Downstream channel of the Yellow River is famous as ‘a perched stream’, and it is the divide of the Haihe River and the Huaihe River. Its present riverbed is generally 4-6 meters higher than the back part of the river ground, 20 meters higher than Xinxiang, and 13 meters higher than Kaifeng. The channel is wide in the upper reaches and narrow in the lower reaches. The widest reach is 24 kilometers, while the narrowest only 275meters in width, so the ability of draining flood is bigger in the upper reaches than in the lower reaches. There are often large fluctuations in the river and the trunk stream swings frequently. The inner beach of the river is the area for flood, and 1,790 thousand dwellers live there. So the task of preventing the flood is fairly hard.

3. The serious water and soil loss

The Yellow River flows through the Loess Plateau, where the area of water and soil loss is the largest and the corrosion intensity is the strongest. The area of water loss and soil erosion is up to 454 thousand square kilometers, accounting for 71 per cent of the Loess Plateau’s area. The water corrosion area of high intensity with the annual erosion modulus lager than 8,000 ton per square kilometer is 85 thousand square kilometers, accounting for 64 per cent of the congener area in China. And the utmost water corrosion area with annual erosion modulus lager than 1,500 ton per square kilometer is 36.7 thousand square kilometer, about 89 per cent of the congener area.

4. The frequent disasters of flood

Records showed that, in about 2,540 years from the Early Qin Dynasty to the Republic of China，the Yellow River had breached or overflowed 1,590 times and changed its route 26 times. That is, on the average, “breach twice every three years and changing its rout every century”. The breach affects a large area from Tianjin City in the north to Jianghuai in the south, which is 250 thousand square kilometers. Each time it bursts, for the heavy sand in water, the channel may be fouled, and the fertile land may be deserted. And the deterioration of ecological environments is difficult to be recovered for long period.

5. The development of economy lags behind.

According to the statistics in 2000, the population of the Yellow River basin is 110.08 million, accounting for 8.7 per cent of the total of China. The ratio of urbanization is 26.4 per cent, lower than the average level of the whole nation. The GDP is 636.5 billion yuan, about 6.8 per cent of the whole nation, and the level of economic development is lower in this area. Also the stockbreeding is lagged. The foodstuff and livestock product per person are lower than the average level in the country. The upper reaches of the Yellow River are where the minority nationalities cluster, and it is a poor area. There the ecological environment is weak. So, it is of great significance to intensify the construction of agricultural economy, make full use of the land and light-heat resources, upgrade the agricultural production, get rid of poverty as quickly as possible and better the ecological environment for the exploitation of the west, the sustainable development of the nation’s economy and the society, and the strengthening of the national unity.

6. Abundant resources and large potential developmental ability.           

The total area of the Yellow River basin is 1,190 million mu, accounting for 8.3 per cent of the total of China. The cultivable land is 197 million mu, about 1.79 mu per person, which is about 1.5 times as much as the average level of the whole nation. The mineral resources are abundant. 45 kinds minerals have been found in China, in the Yellow River Basin there are 37 kinds of minerals. Water resources in the upper-middle reaches, coal resources in middle reaches, oil and natural gas resources in middle-lower reaches are all abundant which is of great importance in China, so it is called ‘the basin of energy resources’. The total available installed capacity is 33.44 million kilowatt, and the annual quantity of electricity generated is 113.6 billion KWH, the second largest one in the seven rivers of China. The known storage of coal is 449.2 billion ton, accounting for 46.5 per cent of that of the whole nation. In the Yellow River basin, the known oil and natural gas are abundant which are dispersed in the oil fields of Shengli, Zhongyuan, Changqing and Yanchang. Shengli oil field is the second largest one in China. There are plenty of other mineral resources in the basin too. The preponderant mineral reserves’ are tombarthite, sulfur, niobium, oulopholite, bauxite, molybdenum and fire-resistant clay and so on. Furthermore, the storage of cobalt, zinc, lead, alkali, sulpho-iron, copper, wolfram and gold is large too. The upper reaches of the Yellow River and the neighboring area are the famous locality of non-ferrous metals.

The implementation of the great-development-of-the-west strategy will produce a good opportunity for the economic development of the basin in the early 21^st century. The economic zones in the Yellow River basin, along the Changjiang River and along the coast line, will form a productivity layout with the shape of ‘π’, which will support the whole nation’s economic growth. The provinces and regions in the Yellow River basin will rely on the advantages of the central cities, the Europe-Asia continental bridge and the natural resources, and eventually form an inter-provincial economic zone with the characteristics of China. So the preponderance of resources will be turned into the economic advantages. According to the strategic layout of the economic development of China in the early 21^st century, the key construction zones in the Yellow River basin are as follows: firstly, the upper reaches’ non-ferrous metal and hydroelectric power base around Lanzhou City, covering the golden zone from the Longyang Gorge to the Qingtong Gorge. The exploitation of hydroelectric power and non-ferrous metal will be accelerated there, and pertinent processing industry will be developed properly too. Secondly, an integrated economic zone with high-tech around Xi’an City. The key is to rely mainly on the processing industry, build this area into a comprehensive and technical base to realize the industrialization of the northwest China. Thirdly, the base of energy in the middle reaches of the Yellow River, including the south of Shanxi Province, the north of Shaanxi Province, the west of Inner Mongolia and the west of Henan Province. It is one of the ten rendezvous of mineral resources in the West. Based on the exploitation of the hydropower in the upper reaches, we should quicken the construction of mineral and hydropower in this zone, enlarge the transmission of electricity and gas from the west to the east. We will turn it into an integrated industrial zone of coal processing, electricity, aluminum and chemical industry and so on. Fourthly, the economic area of the Huanghuaihai Plain along the lower reaches of the Yellow River. This is a base for developing oil, sea and petrochemical industry, and it will be a new investment and development zone relying mainly on the export-oriented industry.

It is estimated that in 2010 the Yellow River basin will enjoy a population of 121 million and a GDP of 1,210 billion yuan. The great-development-of-the-west strategy will promote the construction of infrastructure, ecology and environmental protection. The harnessing and exploitation of the Yellow River is an important component. It is urgent to quicken the harnessing and exploitation of the Yellow River along with the development of economy and society.

Ⅱ. The Current Situations and the Existing Problems

1. The Current Situations

From 1946, esp., after 1949, people began to harness the Yellow River under the leadership of the Communist Party of China. The Party and government attached great importance to the harnessing of the Yellow River. With the implementation of the first programming of large rivers, e.g., Report of Technical and Economic Programming of the Yellow River’s Comprehensive Utilizing, the harnessing and exploiting of the Yellow River are carried out comprehensively, which has ensured the safety of people and property, promoted the development of economy and society and improved the ecological environment.

The peaceful situation has lasted for 53 years in the lower reaches of the Yellow River. Many reservoirs have been built on the trunk and the tributaries, for instance, Sanmenxia, Xiaolangdi, Luhun and Guxian reservoir. The dykes of 1,400 kilometers long in the lower reaches have been strengthened and heightened for 4 times. Strengthening the dykes by clearing away the silt has begun and large-scale channel improvement has been carried out. The detention basins of the Beijin Dykes and the Dongping Lake have been built, and the estuary has been brought under control tentatively. A flood control system in the lower reaches of the Yellow River which is ‘interception in the upstream and discharge in the downstream, bypass and detention on both side of the channel’ has been formed. The non-engineering measures of flood control have been also intensified. The above measures have improved the lower reaches’ ability to resist floods, put an end to the state of easy breach and changing course, and ensured the security of the Huanghuaihai Plain and its steady development.

The development and protection of water resources contribute greatly to the social progress and the economic construction. On the trunk of the Yellow River, 15 water projects and hydropower stations have been built or are being built, with a total capacity of 56.6 billion cubic meters, a total installed capacity of 11.13 million kilowatt, and the mean annual power production of 40.1 billion kwh. Many reservoirs in the tributaries and projects for irrigation and water supply have been built and the groundwater have begun to be developed, thus, the irrigation area has increased from 12 million mu in 1950 to 110 million mu now, including 37 million mu out of the basin. 70 per cent of grain and most of economic crops are produced in these areas, which only accounts for 46 per cent of the total area of the basin. It also solves water problem for 27.27 million farmers, and guarantees water supply for more than 50 cities in or out of the basin and the Zhongyuan and Shengli oil fields. The protection of water resources has been intensified. 216 water quality monitoring stations have been set up to monitor water quality of the trunk stream and tributaries, so water quality of the main reaches is known preliminarily.

Soil and water conservation improves the agricultural conditions and the ecological environment, and decreases the quantity of sand flowing into the Yellow River. The area of the comprehensive harnessing of soil erosion adds up to 0.18 million square kilometers, among which, 1390 projects for gully control, 0.112 million warping dams, 400,000 retaining works of pools, water-logging pools and water cellars have been built, and 97 million mu of cultivated land and 0.115 million square kilometers of soil conservation forest and grassland have been constructed. With the help of the existing measures, the mean annual grain yield has increased by more than 5 billion kilograms, which can solve the food and clothing problem for more than 10 million people. To some extent, water and soil loss and the desertification have been restricted. Since the 1970s, with the measures of soil and water conservation, the mean annual sand flowing into the Yellow River has decreased by about 0.3 billion tons.

2.The existing main problems in the harnessing of the Yellow River

Due to the hard work in the past half century, remarkable success has been achieved in bringing the Yellow River under control. But due to the special features of the Yellow River, the harnessing is extremely difficult. In addition, due to the lack of the infrastructure of the basin and the incompetent management, there are still many problems to be solved now. The danger of flood is still persecuting the people, the contradictions between the supply and demand are becoming increasingly acute, the loss of soil and water has not yet been controlled effectively, and the water pollution is more and more serious.

1. The threat of flood is still persecuting the people

There exist disasters of storm flood and ice run in various degrees in the lower reaches of the Yellow River, the section from Yumenkou to Tongguan and Sanmenxia Reservoir area in the middle reaches, and the Ningmeng section in the upper reaches. The lower reaches of the Yellow River is a well-known perched stream, and the harmfulness of flood is most serious, so it is always the key point of flood prevention. The problems of the Yellow River have an important bearing on the overall situation. Once the dykes breach, the Huaihe River in south and the Haihe River in north would be influenced badly, and the affected area would cover 110 counties belonging to 24 cities in five provinces--Henan, Shandong, Anhui, Jiangsu and Hebei Province according to the present terrain and its features. The coverage would be 0.12 million square kilometers in area including 0.11 billion mu cultivated land and 87.55 million people. The economic losses from flood would be great. The trunk railways of Jingguang, Longhai, Jingjiu, Jinpu and Xinghe, the national highways of 107 and 310, and the main cities of Kaifeng and Xinxiang, etc, would be destroyed by the rush water. Zhongyuan oil field, Shengli oil field, Yanji coalfield and Huaibei coalfield would be damaged seriously. The irrigation network and drainage system, which have been built for many years, and the engineering system for bringing the Haihe River and Huaihe River under control would be wiped out in a day. The flood burst would not only bring great losses for economy and society, but also when the flood fell, the sediment of flood would remain. So the river channel sedimentation and good field desertification would occur, and the harmful effects on the ecological environment would be hard to recover for a long period.

At present, the Xiaolangdi Reservoir has been established and it is in operation, so the flood in lower reaches can be controlled effectively, and the problem of river channel sedimentation has been relieved to some degrees. But the problem of sedimentation in the downstream cannot be solved radically over a long period of time. Also, the quality of dyke in the lower reaches is low, and the river regime changes greatly, so even the moderate flood may cause the dykes breach. In a word, the situation of flood prevention is still grim. There are following prominent problems:

(1) The problem of sediment cannot be solved radically over a long period of time, and the perched stream formed in

history will be existing for a long time. Now, the riverbed is 2 to 4 meters higher than that of 1950s generally, and in some areas the riverbed is 4 to 6, even 10 meters  higher than the ground of land side. In August 1996, the flood peak discharge in Huayuankou station was 7600 cubic meters per second, while the peak level was 0.91 meters higher than that of 22300 cubic meters per second in 1958. To prevent the accretion of bed level, the Xiaolangdi Reservoir’s role of flood sediment retention should be brought into full play, besides, many other measures must be taken.

(2) The flood between Xiaolangdi and Huyuankou has not been completely controlled, and severe floods may appear in the lower reaches as before. With present engineering works, if there were floods with return period of one hundred years and one thousand years, with the peak discharge of 15700 and 22600 cubic meters per second respectively, in Huayuankou station, it would exceed the designed flood control standard in the reaches below Aishan. And the foresight time is only 8 hours. It will be a serious threat to the safety of the lower reaches, and it is very difficult to divert and rescue the people of the beach land and Dongpinghu detention basin.

(3) Because of the poor quality dykes, much hidden danger, and the projects’ lower ability of protecting the dangerous sections, overflowing or breach of levees is still possible. The body of the downstream dykes is mostly made of sandy soil, so the erosion-resistance is lower. There were lots of breach points in history. And the foundation is complicated. The standard of the current danger-prevention projects is low, the crest elevation’s height is not enough, and the slope of the base of dams is abrupt and shallow, so the stability is not up to standard. Although the projects have been reinforced these years, there are still some hidden troubles and weak links.

(4) The control and diversion projects are not perfect and can not reach the standard, and the main channel sways severely, which endangers seriously the safety of the dykes. In the 299-kilometer-long section above Gaocun which has a wide channel, the control and diversion projects are not perfect and the main channel sways severely. The so-called ‘transversal channel’ and ‘diagonal channel’ often occur, so the safety of the dykes is endangered seriously. The current control and diversion project is not up to standard; the stability of the base of dams is poor. In the initial operational period of the Xiaolangdi Reservoir, when the relatively clear water is discharged, the riverbed will be flushed, and channel regime will change more severely, so the probability of dangerous omens will increase.

(5) The quality of the braced dam of the Dongpinghu detention basin is poor, and the stream flow depletion is difficult, so there are some remnant problems for the safety. The Dongpinghu detention basin is a very important measure of engineering to ensure the safety of flood prevention in the reaches below Aishan in Shandong Province. But due to the inferior quality of the braced dam, the leakage is serious when it retains water. The safety precautions are fewer in the area, and the existing bench terraces for preventing flood is not high enough, besides, there are still 0.191 million people having no ways to avoid flood. At the same time, for the accretion of bed level, it is difficult to drain water into the Yellow River.

(6) There are few safety measures in floodplain of the lower reaches, and the existing ones are not good enough. The 3956-square-kilometer-beach between the dykes in the lower reaches belongs to flood area with 1.783 million dwellers, so there are more chances to be submerged. There are few measures and traffic lines for avoiding flood, which cannot meet the demands of withdrawal.

(7) The non-engineering measures of flood control cannot meet the needs of the emergencies. The equipment of hydrologic observation is outdated and in great need. The flood prediction system is backward and not so precise. The conditions of flood control and emergency service are not so good, the equipment is deficient, and the system of flood control is not automatic enough.

Preface III of My Book on Yellow River Research and Management Strategy (by Mr. Guoying Li, YRCC Commissioner)

An unbalanced relationship between water and sediment with less water but more sediment is the outstanding issue of the Yellow River. The main direction of harnessing the Yellow River should focus on developing a harmony relationship between water and sediment. With the implementation of Water and Soil Conservation Project of the Loss Plateau, sediment that comes into Yellow River can be reduced to the greatest extent. At the same time, how to make full use of the sediment transport characteristics of the hyperconcentrated flood, and the potential sediment transport capacity of the natural channel to transport as much sediment as possible to sea, becomes the key technical issue of dealing with the hyperconcentrated flood.

Focusing on the dynamic features, transport principles and processing technology of the hyperconcentrated flood, unremitting long term research and in-depth analysis have been carried out by domestic and foreign scholars throughout the years. Many breakthroughs in understandings were obtained, which provides solid scientific supports for the comprehensive sediment management strategies like “block, discharge, regulate, release and dredge”. For three decades on ends, the author of this book painstakingly devoted himself to the research of managing the Yellow River. From the fundamental characteristics of the hyperconcentrated flood, and the analysis on comparing the field data collected along the main stem and tributaries, he made an important conclusion that a narrow and deep channel is suitable for transporting hyperconcentrated flow. Furthermore, he proposed the necessity of developing the hyperconcentrated flood. With the research on the operation mode of Xiaolangdi Reservoir, he proposed “sediment should be regulated on a multi-year basis, and it should be released at the right time”, and he proved the feasibility of creating hyperconcentrated flood by combined reservoir operations. With the research on regulations of meandering reaches in the lower Yellow River, he proposed the two-bank training strategy to stabilize the main channel, and he studied on constructing an efficient flood discharge and sediment transport channel.

This book focuses on illustrating the following four key topics:

(1)   It introduces flood discharge/sediment transport characteristics and potentials of the narrow and deep channel. With the analysis on the mechanism and the condition of a phenomenon called “the more sediment comes in, the more sediment will be transported.”,  it also explains the dynamics and evolution rules of the hyperconcentrated flood, reasons for abrupt increase of flood peaks, friction characteristics of hyperconcentrated flow, influences of the change in sediment concentration and energy slope on sediment transport, erosion during rising and deposition during the falling of a flood event in an alluvial river, and reasons for the huge flood discharge and sediment transport capacity of narrow and deep channel.

(2)    It illustrates the principles of variation in the meandering reaches, and conditions of the river pattern transformation, and it provides methods to regulate the meandering reaches.

(3)    It explains the key technologies of flow and sediment regulation by the reservoir, application rules and control conditions of multi-year sediment regulations,   mechanical properties of reservoir sediment, possibilities that the hyperconcentrated flood can be created during reservoir emptying, flow and sediment regulation by combined reservoir operations, results of the reduced sediment deposition after multi-year sediment regulations, and the amount of water required for sediment transport that can be saved.

(4)    It explains the outstanding issues in harnessing meandering reaches, causes for the secondary suspended river, analysis on whether the production dikes should be demolished or not, comparisons of the pros and cons between various river training plans, and the necessities of two-bank training. It also provides theories and technologies of how to construct an efficient channel for flood discharge and sediment transport.

It cannot be denied that some views and opinions in this book are still in debates at the theoretical and practical level of studying the Yellow River issues. However, it should also be noted that due to the complex nature of the Yellow River, there are unavoidable disagreements in understandings and management strategies. Actually, some essential debates are very beneficial. The sparkles inspired by collisions between different opinions usually reflect the deep insights of the truth. Just like the Yellow River, which accepts numerous tributaries and flows into the ocean, for harnessing this river, we should allow different opinions, gather their intelligence, take new steps continuously, and march toward the new era. The author of this book, Prof. Pu Qi, has pursued his career of studying the Yellow River for several decades. Reading between the lines, the reader can reveal his assiduous efforts in exploiting the principles of managing the Yellow River, and also the genuine knowledge and profound opinions. I sincerely believe with the publication of this book, great references will be provided for the research on natural principles of the Yellow River, and then to the future developments of management strategies.

Mr. Guoying Li, Professor and Senior Engineer, Commissioner of the Yellow River Conservancy Commission (YRCC), Ministry of Water Resources, P.R. China

January 22, 2009

Society and Economics of the Yellow River Watershed

There are 172 million populations in the basin of the Yellow River and its flood-affected areas, (97.8 million in the basin), around 15.1% of the total population in China, and the cultivated land area is about 0.28 billion mu (0.18 billion mu in the basin), around 19.4% of that in China. The total area of land in the Yellow River basin is 1.19 billion mu (including the inner basin), 8.3% of the country's land, most of which is mountainous and hilly area, 40% and 35% of the basin area respectively, the plain area is only 17%. The rate of the cultivation is 15.1% in the basin, the arable land is 0.18 billion mu, 1.83 mu per person, 1.5 times of that in the whole country, most areas having abundant light and heat resources, and large potentials for agricultural production. There are 0.153 billion mu forest land, the forest-covered rate is 12.9%, and there are 0.419 billion mu grassland, taking up 35.2% of the basin area. In the entire basin, there are also 30 million mu wasteland convenient for reclaiming, largely located in the upland along the Yellow River from Heishanxia to Hekou Town and the delta of the Yellow River's estuary. It is better reserve land recourse for cultivation in China.

There are abundant mineral resources in the Yellow River basin, 114 kinds of minerals were found in 1990. Of the 45 kinds of important minerals having been found in the country, this area has 37 kinds. Such minerals as thulium, columbium,gesso, glass silicon raw materials,coal, alum-clay mines, molybdenum, fire-resistant clay, and so on have the national advantage (reserves taking up above 32% of the national reserves). The natural alkali, sulphur-iron ore, gray rock for cement, tungsten, copper, rock-gold have the regional advantage (reserves taking up 10%~16% of the national reserves). The conditions of mine formation are diverse and the distribution of minerals is wide, but also relatively concentrated, offering advantages of utilization. There are 11 mine-concentrated areas to form all kinds of base and different scale production base for intensive exploitation and utilization.

The installed capacity of hydropower that can be exploited is 31.85 million kw in the Yellow River basin. The power output is 117.9 billion kwh per year, ranking the second among the rivers of China. 91% of the total hydropower resources is distributed in the main stream of the Yellow Rive, for example, the section from Longyangxia to Qingtongxia in the upper reaches and the north main stream in the middle reaches. They have better conditions for hydropower cascade exploitation, the loss caused by submerge is small, the technical economy is superior, and the comprehensive utilization benefits are remarkable.

Most area of the Yellow River basin has been explored for agricultural economy because of the warm climate, enough light and heat and abundant soil resources. The Ningxia-Mongolia Hetao Plain on the upper reaches, the Guanzhong Plain in the middle reaches and the Huanghuai Plain in the lower reaches, are important agricultural bases because of the smooth landform, abundant water resources, convenient irrigation, dense population and better condition for inhabitation. The chief agricultural products take the important place in China, such as wheat, cotton, oil plants, tobacco, and so on. The total agricultural output value reached 103.5 billion RMB in the total basin and the plain in the lower reaches, taking up 13.7% of the total agricultural output value of the nation in 1990, among which 58.5 billion RMB was obtained in the plain in the lower reaches, taking up 7.6% of the total of the nation; the total output of the foodstuff was 63.35 million tons, taking up 14.6% of the total of the country, among which 33.24 million tons were got in the plain in the lower reaches, taking up 7.6% of the total of the country. The total output of the cotton was 1.76 million tons, about 39% of the total of the nation, among which 1.54 million tons were produced in the plain area in the lower reaches, taking up 34% of the total of the country; the total output of oil plants was 2.39 million tons, taking up 14.8% of the total of the country, among which 1 million ton was cultivated in the plain area in the lower reaches, taking up 5.4% of the total of the whole country.

There have been remarkable progresses in industry in the Yellow River basin and the plain in the lower reaches since new China was founded. Many kinds of modern industry were built and developed, especially energy, metallurgy, machine-manufacturing and textile industry, and many industrial cities sprang up, for instance, Xining, Lanzhou, Yinchuan, Baotou, Huhehaote, Taiyuan, Xi'an, Luoyang, Zhengzhou, Jinan, and so on. In recent years, light industry and village and township enterprises which have been ignored develop rapidly and the industrial yield increases quickly because industrial structure is regulated in the whole country. The total industrial output value reached 269.5 billion RMB in the basin of the Yellow River in 1990, occupying 11.3% of the total of the nation of the same year. The energy and mineral resources are abundant in the basin area of the Yellow River. Hydropower in the upper reaches, coal and natural gas in the middle reaches, Zhongyuan Oil Field in the lower reaches and Shengli Oil Field in the estuary delta area. The alum clay, plumbum, zinc, copper, uranium, thulium, and so on take an important place in our country. The zone along the Yellow River is one of the 3 main axes (the zone along the sea, the zone along the Yangtse Rive, the zone along the Yellow River) to be developed. At present, it is important to exploit and build hydropower and nonferrous metal base with Lanzhou as the center, energy and chemical industry base with Shanxi Province as the center, and oil and sea base with Shandong Peninsula and the estuary as the main region. With the reopening of Eurasia Bridge and the construction of traffic lines, it is going to be a benefit to develop the economy of this area. The development in the economic zone along the Yellow River brings high requirement of flood control and harnessing of the Yellow River.

Lang Lang's Piano of Yellow River