What is the impact of water conservancy development in Hongshui River Basin on the local natural environment?

Since the reform and opening up, China's industry, agriculture and light industry have made great progress, and its economic strength has been greatly improved. At the same time, China has made great achievements in water conservancy and hydropower, and the dam construction technology has reached the international advanced level. The construction of large-scale water conservancy projects not only plays a great role in promoting the national economy, but also provides favorable conditions for improving people's life, work and living conditions. However, behind this great achievement, many problems have also been exposed, especially the impact of water conservancy projects on the ecological environment. Such as the change of river and lake water conditions, reservoir siltation and river erosion under the dam, the ecological and social impact of reservoir resettlement, the impact of inundation and isolation on biological resources and species diversity, the impact on the quality of water environment, the impact on the atmosphere, the impact on people's health, the impact on environmental geology and so on.

2 characteristics of the impact of water conservancy and hydropower projects on the ecological environment

Hydropower projects, especially large-scale water conservancy and hydropower projects, often have a significant and far-reaching impact on the regional ecological environment. The impact of hydropower projects on the environment is a multi-level, multi-factor, multi-objective, multi-stage and open complex system. Because of many research fields involved and fuzziness, the main feature of the impact of water conservancy and hydropower projects on the environment is "uncertainty". The uncertainty of environmental impact can be understood as the uncertainty of the natural environmental ecosystem itself, and the environmental ecological combination system created by human activities is more difficult to determine. Although the above effects may be clearly defined in a period of time or in a small range, it is difficult for human beings to control the transformation mechanism of uncertain dynamic systems in the long run.

3. Analyze the impact of water conservancy and hydropower projects on the ecological environment.

In the past, the impact of water conservancy projects on the environment was mainly analyzed from two stages: construction and operation. In fact, it has already had an impact on the environment at the stage of river basin planning. Water conservancy and hydropower engineering is a great influence of human beings on the ecological environment. About the author: Li, female, graduate student. Research direction: hydraulic structure analysis and optimization technology.

3. 1 Impact of planning stage on ecological environment

When building a water conservancy project, the scale of the project should obey the planning goal of water resources development in the whole basin, and the scale of the project determines the impact of the project on the environment. Therefore, if the water resources development plan of the whole basin is completed, the development goals of each flow section will be determined, which will have an intangible impact on the ecological environment of these places. Although this is only "conceptual", it will have a great impact on the future planning and implementation stage and should not be underestimated.

3.2 Impact of Construction Stage on Ecological Environment

In the construction of water conservancy projects, the environmental problems mainly include vegetation destruction, soil erosion, geological disasters, land rolling and occupation, air pollution, noise pollution, water pollution and their effects on human health.

(1) land issue

Engineering waste residue piling and quarry mining occupy a lot of land, which will cause soil erosion and vegetation destruction, and cause great damage to landscape and natural soil.

(2) Water pollution

In the process of construction excavation, cofferdam filling, aggregate washing and grouting, construction wastewater and domestic sewage with high suspended solids content will be produced. If it is directly discharged into the river without treatment, it will pollute the downstream water quality.

(3) Air pollution

Water conservancy and hydropower projects have a large amount of earthwork, which will produce a lot of dust during construction and excavation, which will adversely affect the surrounding air quality, and the exhaust gas from construction vehicles and coal production will also pollute the surrounding air.

(4) Noise pollution

The large construction machinery used in the construction process produces noise, and the blasting construction technology used in mountain excavation also produces noise.

(5) solid waste pollution

Abandoned slag is easy to cause local soil erosion and debris flow, silting up rivers and hindering circulation. If not cleaned up in time, these residues will cause a series of hazards to the local ecology.

(6) Impact on human health

The air pollution and noise pollution caused by the construction have a bad influence on the normal work and life of the surrounding residents. The living and sanitary conditions on the construction site are relatively simple, which may spread some local infectious diseases and epidemics and cause potential dangers to the construction workers.

3.3 Impact of Operation Management Stage on Ecological Environment

After the completion of water conservancy projects, the impact of operation management on the environment is very complicated. After water storage in the reservoir area, the surface area of water body increases, and a large amount of water evaporates, which increases the loss of water resources, which is very serious. According to statistics, the total storage capacity of the whole reservoir in the northern region exceeds 654.38+03 billion m3, and the annual evaporation loss reaches 20 billion m3, which is more than the total water shortage in the northern region. After the completion of the reservoir, due to the long-term high water level and large storage capacity, great water pressure will be generated, which will change the crustal stress in the reservoir area and cause earthquakes, bank collapse and leakage.

And other geological problems to create conditions.

The groundwater level around the reservoir rises,

Causing problems such as land salinization;

Reservoir impoundment

Later, because the upstream water storage raised the water level, the cross section of water increased, the velocity of water flow decreased and the sediment carrying capacity decreased.

For sand rivers,

A large amount of sediment will be deposited in the reservoir,

This will reduce the effective utilization of reservoir capacity,

flood control standard

Greatly reduced, which has a great impact on the service life of the reservoir and shipping; After the completion of the reservoir, the flow velocity in the reservoir area is small and transparent.

Brightness increases,

Is beneficial to photosynthesis of algae,

Water stored in front of the dam for a long time,

Eutrophication is caused by the massive growth of algae,

And also reduces water,

The exchange rate of gas interface and the dilution and diffusion ability of water body,

Lead to that increase of pollutant concentration in the water body,

The self-purification ability of reservoir water is weaker than that of rivers;

After the reservoir is filled,

The water temperature structure changes,

There may be water quality points.

Layer,

Harm to downstream crops and fish spawning;

The inundation of the reservoir area will affect the living environment of terrestrial organisms,

Build a building

The dam broke the living environment of creatures in the original water system,

It will have a direct impact on aquatic organisms, especially migratory fish.

Ring,

May lead to the extinction of endangered and precious animals and plants;

After the reservoir is completed,

Due to the increase of water surface, the climate around the reservoir is affected.

Possible effects, such as rainfall, humidity and temperature, will change to some extent.

After the reservoir impounds water and blocks sand,

When the flood water is discharged, the flow velocity is very large.

It will scour the river bank downstream,

Scouring and silting bar

The change of river bed will cause the reconstruction of river bed, directly affect the stability of dikes, shipping, water supply and estuaries on both sides of the strait, resulting in the original

The buildings in the river lose stability, which is not conducive to irrigation and water diversion.

Shipping will have a greater impact.

Management of large-scale water conservancy projects

Runoff changes greatly, which has a great influence on water and sediment. Even when it reaches the estuary, the estuary will be rebuilt and the coastline will retreat.

Problems such as salinization of groundwater;

Water conservancy project construction,

The ecological balance and hydrological conditions of the original natural river area have been changed.

Conditions,

Directly affect the individuals and populations of primitive organisms,

As a result, some species can not adapt to the new ecological environment and become extinct;

storehouse

There are a large number of immigrants in this area.

Many special facilities should be built for resettlement.

Reclaim a lot of land,

Leading to the ecological environment in the immigrant area

Environmental quality is declining,

It has a certain negative impact on surface vegetation and wildlife habitat;

After the reservoir area is filled with water,

Jiangyan

Without precious cultural landscape, cultural relics and natural scenery, it pays a huge price; In addition, other facilities will be produced.

Negative effects, such as the reconstruction of industrial and mining enterprises, road traffic, power communication facilities, etc.

four

Countermeasures and measures

The construction of hydropower projects is to promote social development and benefit mankind, but it often has a certain negative impact on the environment.

Ring,

Need to consider taking necessary measures,

Minimize the adverse impact of the project on the environment.

Energy and water conservancy project

Bring environmental benefits,

Whether the negative impact on the environment can be minimized is the key to measure the success or failure of water conservancy project construction.

One of the important signs. Therefore, measures must be taken from various aspects to reduce the negative impact of water conservancy projects on the ecological environment.

(

1

) Improve the corresponding laws and regulations.

Improve laws and regulations related to the environment,

such as

People's Republic of China (PRC) Environmental Protection Law

、

Nature reserve article

Example "

、

Provisional Regulations on the Administration of Scenic Spots

And other laws and regulations,

Restrict the order of engineering design and construction from the height of law

Bit,

Really take ecological construction and environmental protection as the fundamental point and breakthrough point of the work.

Seriously destroy and affect the ecological environment.

Conditions,

National nature reserves,

Hydropower construction projects in national scenic spots and world heritage sites,

It should be reassessed.

And review.

(

2

) Adjust the scope of EIA

At present, the environmental impact assessment of water conservancy projects is mainly to evaluate the possible impact of construction contents and activities.

Price,

The environmental protection goal is put forward in view of its possible impact after its engineering goal is determined.

and

The engineering goal is not at the same level,

Therefore, it can't be regarded as the early intervention of EIA in the true sense.

Therefore, it is called "strategic evaluation" to evaluate the planning scheme of the whole basin. From the aspects of basin ecology and environmental protection, it has strategic guiding significance, and the environmental impact brought by development activities can be considered from the overall scope of the basin, and macro-ecological protection measures can be put forward.

(3) development goals should be coordinated with ecological protection goals.

In the past, China's water resources planning often pursued the development rate of 100% according to the cascade development model of river basins, thus ignoring the harm that engineering development would bring to the ecological environment. The impact of water conservancy project construction and river cascade development on ecology and environment should be through comprehensive river basin planning, overall planning, coordinated construction and rational layout. The construction of water conservancy and hydropower projects should adhere to the principle of combining engineering construction with ecological protection, take the rational allocation of water resources as the basic basis, take ecological construction and environmental protection as the fundamental goal, and realize the unity of economic, social and environmental benefits of water conservancy projects.

(IV) Establishment of Scientific and Technological Progress Award for Hydropower Engineering Design and Construction The State may establish a water conservancy engineering expert review committee to review the hydropower engineering design and construction technology built in this period every five or ten years, select the hydropower engineering design and construction technology with the least negative impact on the ecological environment, and give heavy prizes. Make more units and individuals consider the ecological environment as much as possible in design and construction, and try to avoid or minimize the impact on the environment.

(5) Establish local regional environmental monitoring system.

The overall technology of ecological environment monitoring in China is weak, and the construction of monitoring system needs a lot of money. At present, there is no ecological environment monitoring information network in China, but it is feasible to build a local environmental monitoring system. It is suggested that on the basis of the existing hydrological and water quality monitoring station network, small and medium-sized watersheds and typical projects should be selected for pilot projects, and comprehensive analysis should be made on hydrological conditions, local climate, river sediment, fish and fishery, water quality, aquatic organisms, coastal vegetation, birds, hydropower generation and local culture, so as to accumulate experience and gradually popularize them. Fully understand the local ecological environment near the project, and take measures against the hazards that have occurred or will occur soon to minimize the losses in all aspects. Establishing the national regional ecological environment monitoring information network is a long-term task and the goal of our country, which involves many departments and specialties and needs a lot of funds.

To sum up, hydropower projects will have a great impact on the ecological environment, some of which are long-term. Therefore, we should strive to find measures to mitigate its adverse effects and improve and protect the ecological environment. As Gao, secretary-general of China Dam Committee and hydropower expert, said, it is necessary to protect the ecological environment in hydropower development and promote the healthy development of hydropower construction with ecological environmental protection. In particular, it is necessary to establish an eco-friendly hydropower project construction system under the guidance of Scientific Outlook on Development to realize the coordinated development of hydropower development and ecological environmental protection.