Evolution and trend of ecological engineering for river regulation?

Since 1980s, faced with some negative impacts of water conservancy projects on the ecosystem in river regulation, European engineering circles have deeply reflected on the planning and design concept of water conservancy projects, and realized that river regulation should conform not only to the principles of engineering design, but also to the principles of nature. Especially with the development of modern ecology, they further realized that the river management project should conform to the principles of ecology, that is, rivers and lakes should be treated as an important part of the ecosystem, and the river system should not be separated from the natural ecosystem for artificial design. There are many river ecosystems in Europe.

Since 1980s, faced with some negative impacts of water conservancy projects on the ecosystem in river regulation, European engineering circles have deeply reflected on the planning and design concept of water conservancy projects, and realized that river regulation should conform not only to the principles of engineering design, but also to the principles of nature. Especially with the development of modern ecology, they further realized that the river management project should conform to the principles of ecology, that is, rivers and lakes should be treated as an important part of the ecosystem, and the river system should not be separated from the natural ecosystem for artificial design. In Europe, a number of river ecological management projects have been successful one after another, and at the same time, some theories and technologies of river ecological management have emerged accordingly. These theories, experiences and technologies deserve our consideration and reference.

1 river ecological engineering practice in Europe

River ecological engineering began with the ecological management of mountain streams in Europe. As early as the middle of19th century, European industry flourished and the Alps became the industrial base of Central Europe. The frequent occurrence of mountain torrents, mudslides and avalanches caused by large-scale deforestation and vegetation destruction caused by mining, road construction and power station construction has attracted the attention of countries in this region. During the period of 1846 ~ 1884, the forest law and water resources utilization law were formulated. In order to fight against mountain torrents and disasters, a large-scale river regulation project has been built. After nearly a hundred years of treatment, a large number of engineering facilities have played a role in curbing mountain torrents and mountain disasters. However, with the construction of water conservancy projects, it has also produced many negative effects. Especially with the immigration of a large number of immigrants, tourism in mountainous areas has surged, and these negative effects have become more and more prominent. Mainly due to the construction of traditional water conservancy projects, the species and quantity of organisms have decreased significantly, biodiversity has decreased, and the quality of human settlements has deteriorated. Public opinion calls for protecting the Alps and returning to nature. This poses a challenge to the traditional design concept of river regulation project. Engineers began to reflect that the traditional design method mainly focused on the utilization of water and soil resources to prevent natural disasters, while ignoring the harmony between engineering and river ecosystem, the self-purification function of the river itself, and the important fact that the river is the habitat of many animals and plants and the species bank of a large number of organisms. In addition, from the perspective of resource development, the mountain stream area also has the functions of mountaineering, skiing and leisure, and protecting the ecosystem is also the need of water resources development and utilization.

In 1950s, Germany formally established the "near-natural river regulation project", and proposed that river regulation should conform to the principles of vegetation and life.

Relevant countries in the Alps, such as Germany, Switzerland, Austria and other countries, have accumulated rich experience in the ecological engineering construction of river management. The river management schemes formulated by these countries pay attention to the overall function of river ecosystem; Pay attention to the mutual restriction and influence of plant distribution, animal migration and ecological process of rivers in three-dimensional space; Attach importance to the role of rivers as ecological landscape and gene bank. The "near-natural river regulation" project, which began in the 1980s, has achieved remarkable results although it has only a history of more than 20 years. Compared with the traditional engineering method, its outstanding characteristics are that the biodiversity of the basin is obviously increased, the biological productivity is improved, and the species and density of biological populations are doubled. For example, the species of animals in the Oichtenbach Basin increased from 44 to 133 before and after the near-natural treatment, and the number of fish per 100-meter reach in the merke Basin before the treatment was 150, and the biomass was 65,438+55 kg. After management, it was increased to 4 190 respectively. Practice has proved that it is an economical and practical technology to make full use of the self-purification ability of rivers to control pollution.

The regulation of the Rhine River began in 1980s, which provided new experience for the ecological engineering technology of the river. The Rhine River is the largest river in Europe, with a drainage area of 654.38+0.85 million square kilometers and a total length of 654.38+0.320 kilometers. There are 9 countries in the basin, including Switzerland, Germany, France, Belgium and the Netherlands. After World War II, the industries of countries along the Rhine River developed rapidly, which led to the continuous spread of pollution. Pollution mainly comes from industrial pollution and domestic pollution. In the 1970s, the pollution risk increased, and a large amount of untreated organic wastewater poured into the Rhine, which led to the continuous decline of oxygen content in the Rhine and the decrease of biological species, marking the death of biological salmon. 1986, a fire broke out in Schweizerhalle in the upper reaches of the Rhine River. 10t pesticide entered the Rhine River with the water flow, causing a large number of salmon and small animals to die, affecting more than 500 km and reaching the lower reaches of the Rhine River. The accident happened so suddenly and huge that European public opinion was in an uproar. The International Commission for the Protection of the Rhine (1CPR) was established in 1950 and put forward the Rhine Action Plan in 1987, which was unanimously supported by countries in the Rhine basin and European countries. The remarkable feature of the plan is that ecosystem restoration is the main index of Rhine River reconstruction. The main goal is that salmon will return to the Rhine by 2000, so the long-term planning of river management is named "Salmon -2000 Plan". This plan puts forward in detail the conditions required for the biological community to return to the Rhine River and its tributaries, and the overall goal of governance is to make the Rhine River "the backbone of a complete ecosystem". Coastal countries have invested tens of billions of dollars in pollution control and ecosystem construction. By the year 2000, the Rhine River had completely achieved its intended goal, with dense forests, developed wetlands and clear water quality. Salmon has migrated from the estuary to the upper reaches-Switzerland spawns, and fish, birds and amphibians have also returned to the Rhine.

2 Various ecological engineering theories and their evaluation

Tracing back to the formation history of natural engineering theory of river regulation, German seifert first put forward the concept of "river regulation" in 1938. He pointed out that engineering facilities should first have various functions of traditional river regulation, such as flood control, water supply and soil and water conservation. At the same time, we should achieve the goal of approaching nature. Linhe project is economical and can maintain the natural landscape. Make mankind progress from material civilization to spiritual civilization, from engineering technology to engineering art, from practical value to aesthetic value. He particularly emphasized the aesthetic elements in the river regulation project.

As mentioned above, Germany formally established the "near-natural river regulation project" in the 1950s, and proposed that river regulation should conform to the principles of vegetalization and living. It was not until the formation and development of modern ecology that the ecological engineering theory of river management gradually embarked on the scientific track. The development of modern ecology began in 1960s, and gradually formed its own unique theoretical system and methodology. A series of international research programs have greatly promoted the development of modern ecology. Among them, the famous "International Biological Plan" in 1960s, "Man and Biosphere Plan" in 1970s and "International Geosphere-Biosphere Plan" in 1980s. The characteristics of modern ecology are: firstly, it develops into macroscopic research, adopting systematic methods and multivariable and nonlinear models. Secondly, with the in-depth development of the discipline, some branches such as evolutionary ecology, behavioral ecology, chemical ecology and molecular ecology have appeared one after another, expanding the field of ecology. From the application aspect, in order to cope with the crisis of population, resources and environment that began to appear in the 20th century, it promoted the intersection and integration of ecology and other disciplines. Many scientists believe that ecology is one of the scientific foundations to solve the crisis facing mankind. These new interdisciplinary subjects can be classified as "applied ecology". For example, in 1970s, the combination of ecology and human environmental problems gradually formed environmental ecology, and then conservation biology, economic ecology and urban ecology came into being. The combination of ecology and various projects is mainly to absorb the principles and knowledge of ecology in the engineering design concept, change the traditional engineering concepts and technical methods, and form many new engineering theories.

In 1962, Odem proposed to apply the self-organization activities of ecosystem to engineering. He first put forward the term "ecological engineering" to promote the combination of ecology and engineering.

Inspired by ecology, people have a new understanding of river management. River management should not only meet the needs of human society, but also meet the needs of maintaining ecosystem stability and biodiversity. At the same time, the natural or primitive state of the river is regarded as the scale of river management and human intervention, and accordingly the ecological engineering technology and theory are developed.

197 1 year, Schruth thought that the goal of near nature cont 0 1 year should first meet the human requirements for river utilization, and at the same time maintain or create the ecological diversity of rivers. Bidner put forward in 1983 that river regulation should first consider the hydraulic characteristics, geomorphological characteristics and natural conditions of the river to weigh the scale between river regulation and the threat to the ecosystem. 1985, Holzman regards riparian vegetation as a multi-layer structure with various small ecological environments, emphasizes the importance of ecological diversity in ecological management, and pays attention to the harmony between engineering management and natural landscape. In the same year, Rossoll pointed out that the concept of near-nature management should be based on maintaining the highest biological productivity of rivers. In 1989, pabst emphasized that the natural characteristics of streams should be restored by natural forces. 1992, from the viewpoint of maintaining the balance of river ecosystem, Horman thinks that the management of near-natural rivers should reduce the pressure of human activities on rivers, maintain the diversity of river environment and species and the balance of river ecosystem, and gradually restore natural conditions.

River ecological engineering is called "river ecological natural engineering" in Germany and "near-natural fortifications" or "multi-natural construction method" in Japan. The United States is called "natural channel design technology". Some countries have issued relevant technical specifications and standards.

In 1989, Mitsch and others defined "ecological engineering", and Mitsch sometimes used the term "ecological technology". At the symposium on ecological engineering sponsored by the American Academy of Sciences, according to the suggestion of Mitsch, "ecological engineering" was defined as "a design method that combines human society with its natural environment to realize a mutually beneficial sustainable ecosystem." Ecological engineering covers a wide range, including ecological construction of rivers, lakes, wetlands, mines, forests, land and coasts.

As can be seen from the above introduction, there are various theories about river ecological engineering, but we can conclude that the following viewpoints are consistent:

(1) emphasizes the combination of engineering and ecology on the scientific basis of the discipline. In terms of river management, engineering design theory should absorb the principles and knowledge of ecology.

(2) The new engineering facilities should not only meet the needs of human society, but also meet the needs of ecosystem health, and achieving a win-win situation is the ideal goal.

(3) River ecological engineering focuses on protecting the biodiversity of river ecosystem. In the river regulation project, we should respect the natural conditions of the river basin and the survival rights of various biological populations. Water conservancy facilities should provide conditions for the growth, reproduction and habitat of animals and plants.

(4) Understand and follow the laws of the ecosystem itself, and give full play to the self-repair and self-purification functions of nature. Ecological restoration project emphasizes the self-design function of ecosystem.

(5) According to the theory of humanism, emphasize the natural aesthetic value of rivers. In the river regulation project, the natural beauty of the river should be preserved as much as possible to meet the psychological dependence of human beings on natural emotions formed in the long-term natural and historical evolution.

3 the connotation of ecological water engineering

Ecological engineering of river regulation with diverse objectives and contents is a more rational engineering science after people abandon the concept of "conquering nature". It embodies the idea of harmonious coexistence between man and nature, and is a development direction of water conservancy engineering theory and other related engineering theories.

Ecological engineering of river regulation is a very broad concept. It includes soil and water conservation, river sediment control, water pollution prevention, groundwater protection, estuary control and many other aspects. Correspondingly, at present, the ecological engineering of river management involves a wide range of fields. The theory and technical methods of engineering practice in developed countries in the past decade or two are also developing constantly. But after all, it is a new engineering theory, and the ecological engineering of river regulation is also in the stage of exploration and development.

Ecological water conservancy project, referred to as "ecological water conservancy project", is to explore new engineering concepts and technical methods of water conservancy project from one side to reduce the negative impact of water conservancy project on river ecosystem.

The author thinks that ecological water conservancy project, as a new branch of water conservancy project, is a project to study the principles and technical methods of water conservancy project while meeting the needs of human society and taking into account the health needs of water ecosystem. The purpose of developing ecological hydraulics is to promote the harmony between man and nature and ensure the sustainable utilization of water resources.

Ecological hydraulics is an interdisciplinary subject and a practical project. Based on water conservancy projects, it absorbs and integrates the principles and knowledge of ecology and improves the planning and design methods of water conservancy projects. Its connotation seems to include two parts: the basic principle of ecological water conservancy project and ecological water conservancy technology.

The basic principles of ecological hydraulics include studying the characteristics of aquatic ecosystem; Correlation between hydrological and water quality factors and biological communities in different regions; Interaction between water conservancy project and water ecosystem; Principles and mechanisms of ecological compensation for ecological water conservancy projects. The principle of ecological hydraulics is to follow the laws of self-design, self-organization, self-repair and self-purification of ecosystems.

The task of ecological water conservancy technology is to meet people's various needs for water and provide necessary habitat conditions for maintaining and improving biodiversity. Ecological water conservancy technology includes: river regulation, reservoir engineering, constructed wetland and ecological landscape.

The development of ecological water conservancy projects and ecological water conservancy technology in China can learn from the experience of developed countries, but it is impossible to copy them. The reason is that the natural conditions are different, so it is necessary to solve the technical problems of ecological construction according to local conditions. At the same time, different countries have different levels of economic development, and there will be differences in setting ecological restoration goals. From the point of view of engineering planning, when developing and utilizing water flow, it should be clear that rivers are intertwined with their upstream and downstream, left and right banks, and they are in a complete ecosystem, and this important factor should be considered in planning. Major water conservancy projects should not only solve the habitat problem of endangered organisms or "star organisms", but also consider the health of the whole river ecosystem. From the perspective of engineering construction, water conservancy facilities must first ensure the safety of the structure, meet the technical requirements of strength, stability and durability, and have perfect functions. On this basis, they should absorb ecological principles and create conditions for maintaining biodiversity.

Like any engineering construction, ecological water conservancy projects should also be demonstrated technically and economically to ensure the technical feasibility and economic rationality. In the economic analysis of ecological restoration projects, it seems that reasonable ecological restoration objectives should be determined according to objective needs and actual economic affordability. In the ecological restoration project, the most reasonable technical route to develop cheap and practical technology is to make full use of the self-design and self-repair function of the ecosystem. In fact, long before human beings appeared, nature could operate and evolve in an orderly manner, relying on the self-design and self-repair functions of the ecosystem itself. The ecological restoration project we are talking about now also follows these basic laws. Nature does not need human's "gift", let alone "intervention". Our task is to deeply understand the laws of the ecosystem and follow them carefully without creating any laws.

The development of ecological water conservancy project needs the combination of water conservancy project and ecology, and develops in the intersection and integration of disciplines. Ecological hydraulics will be a practical project. Through different types of demonstration projects, explore experience, summarize and improve, and gradually promote, and gradually form norms and standards on the basis of engineering practice.

For more information about project/service/procurement bidding, and to improve the winning rate, please click on the bottom of official website Customer Service for free consultation:/#/? source=bdzd