(Hebei Water Resources and Hydropower Survey and Design Institute, Ministry of Water Resources)

With the acceleration of urbanization in China and the enthusiasm of urban residents for hydrophilic environment, the development of urban areas is expanding along rivers. The construction of urban river landscape engineering has greatly improved the city's taste and the living environment, and its functions and functions in the construction of eco-city are irreplaceable. Then, how to ensure that there is enough water for ecological landscape in water-deficient cities without negatively affecting the water use and water environment in surrounding areas is a severe test for engineering construction advocates.

First, the relationship between rivers and cities

In primitive human society, our ancestors knew that "living by weeds" and rivers were the birthplace of human civilization. Since the existence of human society, the relationship with rivers has roughly gone through three stages: passive adaptation to rivers, interference and occupation of rivers, and existence with river ecology. The history of human development for thousands of years has also interpreted a grand epic of human control of rivers. As long as we browse the map of the world, we can see that almost all cities in the world are built along rivers. This is not a coincidence, it shows that human civilization and survival and development depend entirely on the sufficient water supply of rivers and the benefits of boats.

Humans depend on rivers, and at the same time, they are always in mutual interference and influence with rivers. The changes of rivers not only change the nature, but also affect human beings, and are increasingly affecting their own survival, development and future. In many cases, human harm to rivers is caused by people's ignorance and greed. The pollution of water areas and the deterioration of water environment show that there are problems in people's production and lifestyle in the basin. The decline of rivers means that mankind and civilization will face disaster.

Modern rivers are not only the water source of urban water supply, but also undertake the function of urban flood control and drainage, and rely on natural self-purification ability to absorb the sewage discharged from cities. However, with the increasing intensity of water resources development in the upper reaches of the basin, the accelerating process of urbanization and industrialization, and the rapid growth of urban population, the increasing amount of urban sewage greatly exceeds the natural purification capacity of rivers, resulting in the deterioration of river water quality; People dump garbage into the river at will, and occupy the river channel in various ways, resulting in the continuous degradation of the original function of natural rivers. Over time, rivers will counteract cities and make them develop unsustainably.

As the world enters the 2 1 century, how to balance the sustainable development of human beings and river ecology is a challenge that all countries in the world must face. Recently, some developed countries have realized that human security and happiness at the expense of river ecosystem can only be short-lived. Beginning to consider the existence of river ecology, human beings not only have the right to enjoy the river water resources, but also should care for the river, protect the water quality and ensure that the river ecosystem is allocated the necessary water flow process that will not endanger its river life.

Second, the present situation of river engineering and the situation of urban river landscape improvement engineering

(A) Analysis of the present situation of river engineering

Since the mid-20th century, reservoirs have been built in the upper reaches of many rivers in northern China to store flood runoff. Haihe River Basin is located in the key area of Gyeonggi, and the construction of flood prevention project has a long history. However, it has been nearly half a century to carry out systematic watershed management. 1958 started to build large-scale reservoirs in the upper reaches of the mountain area. After the "June 8" flood, it entered a period of water conservancy construction centered on radical treatment of the Haihe River. A flood control engineering system consisting of reservoirs, rivers and flood detention areas and a flood control pattern in which each river system is divided into zones for defense and diversion into the sea have been initially formed. The completion and application of flood control system has achieved great economic and social benefits in flood control. In order to achieve the purpose of "storage", more than 900 large, medium and small reservoirs1have been built in the upper reaches of Haihe River basin, with a total storage capacity of about 29.4 billion cubic meters. The ratio of total storage capacity to annual runoff is 1.03, which is 6.0 times of the national average of 0. 17, and far exceeds that of the United States and the former. The reservoir dam intercepted the natural river runoff and part of the underground basic flow, which made the natural rivers in the foothills, plains, depressions and lakes in the middle reaches lose their water supply, and the wetland area was transferred from some areas in the lower plains to mountainous areas, resulting in great changes in the ecological environment of the basin. In addition, with the appearance of continuous dry years, the river runoff is reduced, resulting in the drying up of the river course, which leads to the decrease of the available surface water resources, and the groundwater in the area along the river is declining year by year, resulting in the shortage of water resources and the deterioration of the ecological environment, which restricts the sustainable development of the urban economy near the river.

However, with the development of human society, the population and industrial and mining enterprises are constantly concentrated along the river, which not only increases the burden of flood control, but also affects the flood control, the development and utilization of water resources and the ecological environment of urban rivers by discharging sewage into the river, dumping garbage, building temporary and permanent buildings on flood beaches, unplanned interception of water diversion, and disorderly excavation and sand mining in the river. On the one hand, the rapid development of cities, on the other hand, the decline of water environment quality, this problem has widely attracted the attention of governments at all levels. The comprehensive river regulation project triggered by this has been gradually launched in major cities, and it is in the ascendant.

(B) the situation of urban river landscape improvement projects

With the acceleration of urbanization and the further demand of urban residents for hydrophilic environment, the trend of urban expansion along rivers is becoming more and more obvious, and the upsurge of urban river landscape engineering construction has gradually formed and greatly improved the image of the city and improved the living environment. The function and function of river landscape engineering in eco-city construction are increasingly irreplaceable. Taking Hebei Province as an example, in recent years, almost all prefecture-level cities have carried out comprehensive river regulation projects focusing on urban river landscape construction.

Comprehensive improvement project of Hutuo River in Shijiazhuang City: it starts from Huangbizhuang Reservoir in the west and ends at the junction of Gaocheng and Jinzhou in the east, with a total length of 70 kilometers. Among them, the first phase of the project covers Shijiazhuang city section 16 km, and the waterfront landscape belt will be formed before 20 10 July/0/day. The overall project will be implemented in three phases, when it will form a waterfront landscape corridor around the northern part of Shijiazhuang, further improving the ecological environment of the provincial capital, including an increase of 8 million square meters of water surface area, wetland area15 million square meters and green space area of more than 6 million square meters. It is said that the whole project includes water for landscape, wetland and green space, and the water demand will reach 80 million cubic meters. Its water sources are mainly the water from Gangnan and Huangbizhuang reservoirs, the abandoned water from the main canal of the middle route of South-to-North Water Transfer Project in the future, and the metallurgical water and urban reclaimed water.

Water system project around Tangshan city: the total length is 57 kilometers, and 2 1 sluice dam is built. It is said that "digging one river to connect three rivers to form a water system around the city, and adding one lake to connect four lakes to create urban waterscape". By then, the total water storage surface of the built-up area will be 16.5 square kilometers, the water storage capacity will be 20 million square kilometers, and the annual water demand will be 39.4 million to 58.88 million cubic meters, forming ".

Baoding City Water System Project: According to the overall layout of "connecting the two reservoirs, transferring water from the west to the east, passing through the government and replenishing the lake", it is divided into four major projects: water source project, rain and sewage diversion project, landscape project and comprehensive improvement of flood control embankment. From the Xidayang Reservoir, 30 million cubic meters of water was transferred to the urban area through 70 kilometers, so that seven inland rivers were paid off. By then, the urban water surface area will be 595 hectares, and the urban river network density will rank first in the province, making it a unique water network landscape city in North China.

Taking water as the soul, Chengde City will build a "landscape garden city with two waters around the city, mountains and rivers reflecting each other, full of spirituality and vitality", with an additional water surface of 4.36 million square meters and a water landscape area of/kloc-0.2 million square meters.

Hengshui City's "Water City Lake City Project" will excavate and renovate 18 lakes and 30 rivers, so that the wetland area on the lake surface will increase from 75 square kilometers to 100 square kilometers.

Zhangjiakou has made great efforts to build a regional central city, harnessing Qingshui River by a high standard of 23 kilometers, and has started the comprehensive harnessing of Yanghe River with a total area of 38.5 kilometers and the construction of Minghu Park with a total area of 106 hectares.

In addition, Xingtai City proposed to create an urban landscape of "two rivers around three mountains, six waters embellishing eight gardens"; Qinhuangdao City will build Liuhe River into a safe river, a clear water river and a landscape river according to the comprehensive management plan of Liuhe River system in the urban area, forming a landscape belt along the river with "one garden, two islands, four bridges, five fields, six belts and sixteen views"; Handan city strives to create a city of happiness for the people; The comprehensive improvement project of the South Canal in Cangzhou City and the landscape belt project of the Longhe River system in Langfang City.

Looking at 1 1 city's river course comprehensive improvement project construction, a common feature is that it is mainly based on urban river course landscape construction, and all of them need a certain amount of water resources as support. In order to provide landscape water consumption, it takes hundreds of thousands of cubic meters at least and tens of millions of cubic meters at most.

Three, to prevent the river landscape improvement project to expand the urban-rural differences in water resources allocation.

(A) The urban-rural differences in water resources allocation do exist.

It is an indisputable fact that when a severe drought occurs, it is often the rural areas and farmers who suffer the most. The worst drought in southwest China in the spring of 20 10 fully illustrates this problem. According to Wang Xing, a special correspondent of Wen Wei Po on March 3, 20 10, the water consumption between urban and rural areas is very different in the same drought. In Kunming, although the drought lasted for more than five months, as far as the life of residents in Kunming city is concerned, except for the increase in the prices of some grain, flowers and tea, it has hardly been affected, and there is basically no restriction on water use. Some water-consuming industries, such as bathing centers, are still crowded. As a water source project in Kunming, Yunlong Reservoir supplies 250 million cubic meters of water to the main city of Kunming every year, accounting for more than 70% of the total water supply in the main city of Kunming. The water supply is in the form of tunnel, and the water discharged from the reservoir is delivered from underground to the urban area, and no water is needed on the surface along the way. The villagers living around Yunlong Reservoir said, "We can't drink water by leaning against the reservoir, so we have to find water by ourselves." At present, in rural areas in arid areas, a bucket of water is always used by farmers for 5 ~ 6 times, which is in sharp contrast with urban water use.

Why can't the countryside and farmers next to the reservoir use water? This difference in water use undoubtedly reflects the huge difference between urban and rural areas. A professor at Yunnan University said: "The urban-rural gap is narrowing in some places, but it is still expanding in quite a few places. Everyone has long been accustomed to taking the city as the center and giving priority to the allocation of resources to developed areas. Once affected, it is often the underdeveloped rural areas that suffer losses first, but the feeling of the city is not obvious. " The professor further explained: "In fact, the farmers in the water source originally owned water resources, but they were artificially transferred. The construction of reservoirs and hydropower stations ensures the production and life of the downstream, but at the expense of the interests of the upstream residents. When the drought comes, farmers in the water source will suffer first. Objectively speaking, it is not enough for the government to consider the interests of farmers' water resources. " Similar differences between urban and rural areas are not only reflected in the right to use water resources, but also in the construction and maintenance of water conservancy facilities. Dawa, director of the Yunnan Flood Control and Drought Relief Headquarters Office, said, "Although 55 14 large, medium and small reservoirs have been built in Yunnan by the end of 2009, most of these projects are concentrated in the vicinity of urban areas such as Dizhou City, and a considerable number of facilities were built in the 1960s and 1970s, which have been in disrepair for a long time." An engineer from Yunnan Water Conservancy and Hydropower Survey and Design Institute told the reporter: "For rural water conservancy facilities, there are basically small reservoirs and small ponds and dams, and there are some small water cellars dug by the masses spontaneously. When there is rain, they can also store some water. Once the drought comes, they all lose their functions completely. Farmers either ask for their own water or have to wait for the water delivery truck at home." Professor Yunnan University said: "Instead of donating money and water to fight drought passively, it is better to take effective measures to save water in cities, and at the same time use the saved funds and water resources to improve farmers' basic living conditions. When necessary, the government should consider giving farmers, especially those in water sources, appropriate economic compensation, which is also an ecological compensation." Except Yunnan and Kunming, the situation in other places is actually similar. It is inevitable to give priority to the allocation of resources to developed areas, and the government's macro-control and policy guidance are particularly prominent.

(B) River landscape project has further boosted the allocation of water resources to the city as the center.

As an important factor of urban natural environment, river system is the skeleton network of urban construction, which affects the appearance, nature and land layout of the city. The river system is more important than the buildings in the city in influencing the characteristics of the city to some extent. Therefore, in the process of urban planning and construction, we attach great importance to the management of river system, and make use of urban rivers and lakes and their attached green spaces to create a distinctive urban river landscape with many functions such as human settlement, leisure, tourism, commerce and culture.

The most important prerequisite for the construction of urban river water landscape engineering should be to have sufficient water source guarantee. Only in this way can we truly meet the good ecological environment of mountain-water cities.

People may have retained the nature of "living by weeds" of human ancestors. In recent years, as long as there is water, the construction of commercial and residential areas there will be hot and the price of real estate there will soar. However, passive water will not last long, and the artificial water surface will not be supported by subsequent water sources, and then it will either dry up naturally or be a stagnant pool. However, the pursuit of economic interests and the concept of quick success and quick success often contribute to the construction of urban water landscape. After widening roads and plazas, all over the country have built dams and dams in urban rivers to expand water bodies and water surfaces, and water landscape construction has become a fashion. The scale and speed are beyond people's expectation.

Urban river is a subsystem of river basin water system, and the development and utilization of water resources in river basin by urban river water landscape system will inevitably lead to the spatial and temporal redistribution of water resources in river basin. The planning of urban river landscape engineering should be coordinated with the comprehensive planning of river basin water resources, and the planning and construction of urban river landscape must be considered from a wider scope, and the measures of urban water landscape engineering should be rationally optimized and comprehensively utilized. There is a shortage of water resources in northern China, and the degree of development and utilization of water resources in the basin is already very high. If the urban river landscape project is developed on a large scale and the water consumption of urban water landscape is expanded at will, the use and consumption of water resources will be increased. If the urban river landscape project only considers the development needs of the city itself, it will affect the agricultural water consumption in the lower reaches of the river and the deteriorated river ecology. The river landscape improvement project has further promoted the city-centered distribution trend of water resources allocation.

(C) Urban river landscape engineering planning should rationally allocate water resources.

Effective progress has been made in the conservation, protection and rational utilization of water resources in China, but the contradiction between supply and demand of water resources is still very prominent. More than 400 of the 669 cities in China are short of water supply, including 1 10. Of the 32 mega-cities with a population of over one million, 30 have been plagued by water shortage for a long time. Then, how to ensure enough water for ecological landscape in water-deficient cities is a serious test for engineering construction advocates. The most ideal method is of course to increase the sewage treatment capacity and rely on reclaimed water resources to meet this water demand. However, from the current situation, this way out is not realistic. Therefore, transferring water from the upstream reservoir or from other areas is still the main source of ecological water in many cities.

In fact, the water landscape of cities in the northern region is not indispensable, and it should be regarded as a luxury to some extent. Even if we do it, we don't have to do it on such a large scale and with such high standards. For example, large fountains, artificial lakes and other landscapes have been built in various hotels in Las Vegas, the gambling city in the United States. However, because Las Vegas is a city in the desert and has no water source, the landscape water in the city is transported from afar by giant trucks. What's more, once the urban water landscape is built, it must be considered to exist and run for a long time. The water stored in urban rivers and lakes must maintain a certain amount of water, a suitable water level and a qualified water quality. Otherwise, it will be dry to the bottom or a pool of stagnant water and smelly water. So how can we meet the requirement of maintaining landscape water demand by long-term external water transfer in a water-deficient city? In a developed city, residents' domestic water consumption and economic growth depend on transferring water from surrounding areas to solve environmental problems; The construction of water landscape also needs to transfer water from the surrounding areas, especially when the water resources transfer-out areas are both water-deficient or even seriously water-deficient areas, which is tantamount to "digging up meat to patch up sores". When the builders of a city plan the urban water landscape with good wishes, their eyes often focus only on the city in front of them, and their focus is often only on the city's own interests, but they ignore the harmonious relationship between the city and its surrounding areas, even economically underdeveloped areas; Ignore the "* * * life, * * existence, * * * glory, * * * joy and * * * elegance" relationship between the city and its surrounding areas, and the relationship between honor and disgrace and * * *.

Historical experience has proved that if resources, manpower, capital and logistics in rural areas are always flowing in one direction to cities, not only will rural areas become poorer and poorer, but cities will also become more and more deformed. In addition, relevant data show that every time developed countries build 1 hectare of forest, it will endanger the land of developing countries1hectare. By the same token, when we build a waterscape in the city, a large area of land will inevitably suffer from water shortage when water resources are transferred out. Therefore, if we don't proceed from reality, in order to blindly develop urban water landscape projects and build urban image projects, we will develop water landscapes on a large scale in cities that are already seriously short of water and divert water from surrounding areas, which will not only directly aggravate the contradiction between supply and demand of water resources in surrounding areas, thus increasing the pressure on production and life there and inducing water disputes. This practice obviously deviates from the purpose of harmonious coexistence between man and nature and the construction of a harmonious society advocated by the central government.

(D) Urban river landscape engineering construction should be conducive to social harmony.

For a long time, local interests and short-term interests have always been an indelible force, which has undermined the overall interests and long-term interests of society in various ways. When there is water shortage, they compete for water with each other, and when there is more water, they beggar their neighbors. With the continuous development of economy and society, the demand for water resources is increasing everywhere. The construction of urban water landscape cannot proceed from local local interests unilaterally, affecting or destroying the overall and long-term interests of river basins or regions, and even making the unstable factors caused by water shortage more obvious and prominent. Never beggar your neighbor, simply divert the sewage to the surrounding and downstream areas for the sake of cleaning the water in urban rivers and lakes, so that the pollution source will move, causing pollution to the water environment in other areas and causing water pollution disputes.

IV. Conclusion

At present, China's urban and rural social and economic development is not balanced. Large-scale construction of urban river landscape projects in large and medium-sized cities has promoted the allocation of water resources to be more city-centered, and expanded the existing differences between urban and rural areas in water resources allocation. In the process of urbanization, we should strive to build an eco-city, make great efforts to comprehensively manage urban rivers, improve urban taste and improve urban environment, but we should prevent a large number of precious water sources from water-deficient areas from being transferred to the city by administrative means to create water landscapes, and unilaterally pursue the luxury improvement of human settlements and commercial and residential environments. The government and policy makers should focus on the vast rural areas beyond the city. Carefully examine the resources obtained in our city and whether the good environment created has affected the life and production water of rural areas and farmers outside the city; Whether it harms the vital interests of people living outside the city. If Shui Yuan, which flows in urban rivers, is the life-saving water for rural production and life, and if the sewage from urban rivers is discharged or diverted to keep the landscape water of urban rivers clean, which pollutes the rivers and environment in downstream areas, it is obvious that there is still a certain gap between our work and the idea of building a harmonious socialist society.

references

[1] Wang Yujun, et al. Reflections on the lack of urban water landscape construction planning. Water Planning and Design, 2009( 1)

[2] Zheng Lianhe, et al. The relationship between northern rivers and neighboring cities and comprehensive management. Haihe Water Conservancy, 2008(5)

[3] Sun Jingliang. Restoration and reconstruction of water environment and utilization of flood resources in Haihe River Basin. Journal of Kunming University of Science and Technology, 2007,32(2A)

[4] Huang Cheng. Thinking about urban water landscape construction. Haihe Water Conservancy, 2005(4)

Feng Yuejing. Hutuo River 16 km landscape belt. yanzhao metropolis daily, 20 10-05-0 1

[6] Dong Lilong, et al. The water system around Tangshan is navigable and livable in North China. Hebei Daily, 20 10-04-30

[7] Xu Shunlan, et al. Baoding has made great efforts to build a large water system. Hebei Daily, 20 10-06- 10

[8] Ma Guochen, et al. Looking at Chengde in the year of decisive battle: a landscape garden city. Hebei Daily, 20 10-05-06.

[9] Wang Cuilian, et al. Zhangjiakou strives to build a regional central city. Hebei Daily, 20 10-04-29

[10] Qi Xiangtai, et al. Handan strives to create a city of happiness for the people. Hebei Daily, 20 10-06-09

[1 1] Xing Shiyan, et al. "Crouching Cows Rise": An Interpretation of Xingtai Urban Construction. Hebei Daily, 2008-09- 18

[12] Ma Chaoli. Harbor City Renovation "Six Rivers" Weaving City "Green Ribbon". Hebei Daily, September 2008-18

[13] ma yanming, et al. "Hengshui lake city accelerates": Hengshui lake eco-city seeks to build a leisure resort. Hebei daily, 20 10-03-02

[14] Sun Zhanwen, et al. Langfang is a famous leisure and business city around Bohai Sea: the dream of a young city. Hebei Daily, 20 10-05- 17

[15] Hongxu, et al. Cangzhou builds the economic growth pole of central and southern Hebei. Bohai Morning Post, 20 10-03- 17

[16] Wang Xing. Why are farmers always injured in the face of drought? Wen Wei Po, 20 10-03-3 1