Most of the world's river governance has experienced two stages, from "passive defense and flood resistance" to "scientific planning and river management according to law". While the artificial transformation of natural rivers has brought huge benefits to mankind, it also inevitably caused incalculable damage to the ecological environment of the river. In the process of economic development abroad, a large number of hard retaining walls and revetments have been built to resist floods, and the disorderly discharge of pollutants has also caused serious river pollution. Traditional river development and governance models have shown more and more drawbacks. In the 1990s, many Western countries reflected on the destruction of the natural environment of rivers and gradually restored the damaged natural environment of the river. In Europe, many countries are actively demolishing the reinforced concrete embankments built in the 1960s and 1970s. Build ecological river embankments, carry out pollution control, and restore the shape of the river. These measures have achieved good results.

At present, the concept of river ecological management is the general trend. However, since most of our country's river management companies are initially involved in it, they lack experience and are prone to many misunderstandings.

1. Pollution source governance and ecological governance are not synchronized

The main reason for the deterioration of water quality in most rivers is the discharge of point sources and non-point sources along the line. In the design of river ecological treatment, some designs often only focus on the application of ecological measures, and fail to take measures to the source of the deterioration of water quality. The pollution source treatment is not synchronized with the ecological treatment. With good results, water quality will continue to decline, aquatic animals and plants are difficult to survive, and the ecosystem cannot be successfully constructed in this environment. The role of enhanced purification measures is limited and the cost is high, which cannot reflect the spirit and goals of river ecological management.

Therefore, the main pollution sources of the river should be analyzed during the design, and measures such as interception and pipe management, in-situ treatment, ditch purification, and wetland purification should be adopted for the main pollution sources to effectively reduce the amount of pollutants entering the river before carrying out ecological treatment. Can get twice the result with half the effort.

2. Not paying attention to the circulation of the river

"Flowing water does not rot" reflects the purification ability of flowing water and the ability to maintain water quality. However, some designs do not pay attention to the flow of river channels. For dead-end or non-circulating water bodies, ecological measures such as ecological revetment, plant construction, and intensified purification are taken according to the site conditions, in order to achieve the goal of improving water quality. These measures may achieve the expected results, but their stability cannot be guaranteed, and the operation and maintenance management workload is large, and the operation cost is high.

(Powerful flow aerator, super large flow circulating water)

Therefore, when designing, it is necessary to actively explore the scheme of water flow, such as water system communication, use culverts, newly excavated ditches, etc. to connect the water system; water circulation, use circulating pumps, mixers, etc. to improve the flow state of the water body, and to circulate the water body; reasonable Dispatch, use the water level difference of the outer river to make the water flow, and make full use of the self-purification capacity of the flowing water and the water quality maintenance capacity to improve the water quality.

(Floating fountain type aerator, oxygen-enhancing landscape)

3. Excessive emphasis on land landscape design 　　

Landscape can fully demonstrate the effect of river governance and leave a good impression on people. However, the water ecosystem is located underwater, and it is difficult for the naked eye to judge the integrity and quality of the water ecosystem, and it is impossible to determine the degree of water quality improvement. Therefore, some designs overemphasize land landscape design, use most of the funds for ecological management in the construction of land landscapes, and make the theme of the design of the land green belt clear and beautiful, while ignoring the construction of underwater ecology, putting the cart before the horse. , Deviated from the overall goal of river ecological management.

(Is it treating the river or doing greening?)

We must realize that land landscape landscaping and landscaping do not mean ecologicalization, and the thinking must be changed from "focusing on landscape" to "ecology and landscape", and strengthening the embodiment of the ecological concept of land and water, especially The ecological interception and buffer function of land greening should be brought into play.

4. River channel background investigation is not comprehensive

Traditional river governance background surveys mainly collect data on hydrology, sedimentation, geology, planning, land acquisition and resettlement, and topography. In addition to the above data, river ecological management also needs to collect data on river pollution sources, water quality, water ecology, sediments, land plant communities, and hydraulic structure scheduling and operation. If necessary, water quality, water ecology, sediment And so on to carry out supplementary monitoring and investigation. At present, most of the river ecological management seldom conduct a comprehensive survey of the river background. At most, the water quality data is collected, and the remaining data is less collected, or relevant data cannot be collected. The supplementary survey costs are high, and the construction party does not Willing to take it.

Therefore, the background data of the river course is not comprehensive, it is difficult to correctly diagnose the problems of the river ecosystem, and it is impossible to explain the main reasons for the damage and lack of the ecosystem, and it is difficult to formulate a targeted and feasible Good ecological management plan.

5. Ignore the construction of other habitats

At present, most of the design units engaged in river ecological management are in the water conservancy industry. Many units have not yet provided the ecological and environmental professional direction, or have personnel engaged in ecological and environmental design, and they do not have a deep understanding of the connotation of river ecological management. Some designs The staff believes that the ecological revetment of the river course is to carry out ecological treatment, and the ecological river course is combined with plant treatment. The other parts are designed according to the planned section, ignoring the construction of other habitats.

(Do you think something is missing?)

We know that the river habitat includes plane form, cross-section form, revetment material, river bottom habitat, etc., which can be combined to form a continuous and diverse habitat base to provide a suitable habitat for aquatic animals and plants. Ecological bank protection is only part of the construction of river habitats. Paying attention to its construction and ignoring the construction of other closely related habitats will not achieve the goal of diversified habitats. The survival of aquatic animals and plants will still be greatly restricted, which restricts the integrity of the ecosystem. Build.

6. The ecological revetment does not match the surrounding function positioning

In the construction of ecological rivers, many new building materials are used to replace traditional cement and concrete to build revetments or retaining walls. While improving the aesthetics of the river, it also increases the interaction of the land and water system, reflecting the ecology of the new materials Affinity. There are many kinds of hydrophilic materials, mainly natural materials (wooden piles, willow branches, soil slopes, etc.), ecological fabrics (ecological bags, coconut shell fiber blankets, etc.), gabion nets, and geosynthetics (geogrids, geotechnical Nets, etc.), porous ecological blocks, etc. These materials have different shapes and features. Some designs use more rigid revetment materials in the section of the river that crosses the countryside, making the river look harder and incompatible with the surrounding landscape; while the use of willow branches and other materials in the revetment of the urban area, although it is ecologically better, The urban population is densely populated and the security is relatively poor.

Therefore, when we choose bank protection materials, we must first grasp the functions of the plots surrounding the river channel, and choose the bank protection materials that can be matched with it, in order to highlight the ecological nature of the river channel.

7. Do not configure aquatic plants randomly according to water quality

The water quality of adjacent rivers and the growth of aquatic animals and plants show different characteristics due to the different sources of pollution in the river, the different topography of the river bottom, and human interference. Regarding the river course in the same area, regardless of the main reason for the damage to the ecosystem, the difference in water quality, water ecological status and the preservation and protection of existing plants are not considered. The aquatic plants are basically the same. The targeted allocation of aquatic plants cannot reflect the characteristics of river ecological management and is not conducive to the restoration of plant communities and the construction of ecosystems.

(Is it appropriate to arrange such a full river?)

8. Completely reject the use of hard retaining walls

The use of hard retaining walls in traditional river management has blocked the exchange of material and energy in the water and land ecosystems, which is more harmful from the ecological point of view. However, the rigid retaining wall structure is safe, covers a small area, and has outstanding advantages. River ecological management is to implement ecological measures under the premise of ensuring the safety of flood control. Flood control is the basic function of the river, and the stability of the bank protection structure is the first.

In case of river ecological management, if you encounter a river section with a narrow river and a large overflow, in order to ensure the safety of the bank, it is not necessary to completely reject hard materials, and you can appropriately use hard retaining walls or a combination of hard materials and ecological materials. Retaining wall structure. At the same time, set up ecological compensation areas in some river sections, appropriately widen the river channels, and use ecological materials with good hydrophilicity to construct bank protection, so that the water and land material and energy exchange of this section of the river can be concentrated in this area for compensation.