The most serious ecological and environmental problems in the Three Gorges area and the main measures

1 ecological environment problems in the three Gorges reservoir area

In recent years, the reservoir area has continuously strengthened environmental protection and ecological construction, and actively carried out ecological environment integration.

In the renovation project, four nature reserves have been built, and the soil erosion control area exceeds 1 000 km2. The forest coverage rate and urban greening rate have improved, and the ecological environment has improved. However, the deterioration trend of the ecological environment in the reservoir area has not been effectively controlled, and the environmental protection work still faces several major problems.

1. 1 Water pollution is serious.

1999 * *10/0/0,000,000 t, with a total COD discharge of 278,000 t, of which 7/kloc-0,000,000 t was industrial wastewater, and nearly13 industrial wastewater failed to meet the standard. Domestic sewage is 300 million tons, and the centralized treatment rate is only 7.7%. According to the comprehensive evaluation results of 1999 Yangtze River water quality, among the seven monitoring sections in Chongqing section of the Yangtze River/kloc-0, only 5.9% are Class II water bodies, 7.6% are Class III water bodies, 70.6% are Class IV water bodies and 5.9% are Class V water bodies. The 10 indexes of coliform bacteria, non-ionic ammonia and COD in Chongqing section of Yangtze River, Jialing River and Wujiang River exceeded the standard. The secondary rivers in the reservoir area are seriously polluted, and the water quality of 56% sections can not meet the requirements of water function.

In the whole urban reach of the Three Gorges reservoir area, the total length of the reach whose water quality is affected by sewage is 28.97km, and the width is 2 ~ 150 m, among which the pollution zone in Chongqing is the longest, accounting for 74.7% of the total length of the pollution zone in the reservoir area.

1.2 A large amount of domestic garbage

The annual output of industrial solid waste in the reservoir area is 7,436,200 tons, and that of hazardous waste is 395,000 tons. Over the years, the storage capacity of industrial solid waste has reached more than 30 million tons, and the comprehensive utilization rate is about 43%. According to the calculation of domestic garbage per capita generated by urban non-agricultural population 1kg/d, the total domestic garbage in the Three Gorges reservoir area is 1.78 million t/a. At present, it is only basically cleared out of the city for simple treatment, and the harmless rate is only 7. 1%. All kinds of waste are piled up in disorder, and some even dump directly on the coast. Under the influence of rain soaking and flood scouring, a large number of pollutants flow into rivers, causing serious water pollution in the Three Gorges Reservoir, which is one of the main reasons for the excessive coliform bacteria in the water body of the Three Gorges Reservoir and the deterioration of the water quality in the main stream during the wet season.

1.3 Ship pollution is becoming more and more serious.

The annual output of ship domestic garbage in the reservoir area is about 30,000 t, of which about 8,000 t enters the river, and the ship domestic sewage is about 6,543.8+0.8 million t, including about 400,000 t of oily sewage, about 600t of COD and about 654.38+000 t of petroleum. Pesticide and fertilizer pollution, centralized aquaculture pollution on water surface and pollution from township enterprises are also prominent in the reservoir area. 1999 The amount of pesticides used in the reservoir area reached 1 160.6t, of which organophosphorus pesticides accounted for more than half.

1.4 The forest coverage rate is low, and the urban per capita green space is less.

Years of destructive reclamation, the disorderly development of township enterprises and the development and construction of new urban areas have seriously damaged the original forest vegetation, resulting in a significant decrease in the forest coverage rate in the reservoir area, which is only 22.3%. The forest coverage rate of most districts and counties on both sides of the reservoir area is only 7.5% ~ 13.6%, with an average of less than 10%. Moreover, the structure of forest species is not reasonable, the proportion of mature forests, special forests and economic forests is low, and the proportion of young and middle-aged forests is extremely large. The proportion of young and middle-aged forests in Fuling, Fengdu and Fengjie is as high as 90%, and there are basically no mature forests. The forest community structure in the reservoir area is simple, the function is out of balance, and the vegetation shows a reverse succession trend, from forest degradation to bare rock on shrub slope.

The greening level of towns at all levels in the reservoir area is low. The per capita green space in the main urban area of Chongqing is only 2.08m2, which is only 39.2% of the national urban green space of 5.3m2, with a population of 3.5 million.

The above cities are at the bottom. There are even fewer other counties and cities. For example, the per capita public green space in Wanxian City is only 1.8m2, and that in Fengjie County is only 0.3m2 ..

1.5 The ecological imbalance is serious.

Biodiversity is an important indicator of ecological balance and an important content of ecological construction. According to statistics, there are more than 6,500 species of animal and plant resources in the Three Gorges reservoir area, accounting for about 20% of the total number of animal and plant species in China.

There are 8 and 6 species of first-class protected animals and plants, 35 and 22 species of second-class protected animals and plants respectively.

There are abundant tertiary relict plant in the Three Gorges reservoir area. But because of the forests on which biological populations depend.

The forest coverage rate is very low, and there are few virgin forests below 1000m above sea level, which leads to forest musk deer and leopard cat.

And the tigers and leopards in the reservoir area are on the verge of extinction. Some aquatic species, such as China.

First-class protection of aquatic animals, such as baiji, paddlefish, Chinese sturgeon and Yangtze sturgeon, and second-class protection of aquatic animals.

The finless porpoise, mullet and other animals are all facing the ecological structure and health changes brought about by the completion of the Three Gorges Reservoir.

The grim situation of environmental damage. This situation directly threatens its survival and accelerates its endangerment. grow

If the deterioration of this state cannot be effectively stopped, it is very likely to cause irreversible species extinction.

1.6 Serious soil erosion.

The Three Gorges reservoir area is one of the areas with serious geological disasters in China because of its high mountains and steep slopes and complex geological structures. According to the reexamination data of the immigration department in 2000, there are more than 20,000 geological disasters in the Three Gorges reservoir area, including landslide 1.302 with the leading edge below the submerged line of 1.75m, with a volume of 3.334 billion m3. There are 1 654,38+0.33 areas with different degrees of danger and potential danger, accounting for 87% of the total number of landslides. Due to the landslide, 405 villages and 60 towns decided to move.

Soil erosion in the Three Gorges reservoir area is serious. The area of soil erosion accounts for 62% of the total land area, reaching 50.0255 million mu, and the total amount of sediment flowing into rivers every year reaches more than 654.38+0 billion t, which will inevitably increase the sediment content of the Three Gorges Reservoir. Although the Three Gorges Dam is designed with dredging holes, it cannot solve the problem of dredging the 600-kilometer river course in the reservoir area. Only by strengthening ecological construction and maintaining soil and water can we solve the problem.

1.7 The pollution of ecological environment has changed from city to city.

The rapid expansion of rural areas, the acceleration of urbanization and the disorderly development of township enterprises have intensified the spread of environmental pollution from cities to rural areas. The scope of acid rain has obviously expanded to the outer suburbs, and the contour area of pH 4.5 has covered almost the whole reservoir area. More than 90% of the area is acidic precipitation area, and the frequency of acid rain for many years is 60% ~ 90%, and the average pH value of acid rain for many years is about 4.3. The direct economic loss caused by air pollution in the reservoir area reaches 2 billion yuan every year.

The main reasons for the above problems are: unreasonable industrial layout, serious shortage of urban infrastructure, extensive growth mode that worsens the ecological environment, unreasonable energy consumption structure, serious shortage of environmental protection investment and weak environmental management. With the opening of the western development and ecological construction, these problems are gradually being solved. For example, the Yangtze River basin (focusing on the Three Gorges reservoir area and its upper reaches) and the Yellow River basin (focusing on the Xiaolangdi and above) were included in the "Tenth Five-Year Plan" water pollution control focus; Implement natural forest resources protection, returning farmland to forests and grasslands and sand prevention and control projects; Chongqing has implemented the "green mountains and green waters" project focusing on the Three Gorges reservoir area and the "landscape garden city" project focusing on the main urban area; Since 1990, more than 6,000 foreign experts, scholars, representatives of international organizations and government agencies have visited Chongqing for environmental protection and exchanges. Chongqing is listed as a demonstration city of environmental cooperation in China, and has obtained the environmental protection loan from the World Bank.

2 Countermeasures to solve the ecological and environmental problems in the Three Gorges reservoir area

As early as 1994, the China 2 1 Century Agenda promulgated by our government has clearly taken the sustainable development strategy as an important guiding principle for the medium and long-term planning of national economic and social development. The key to the sustainable development of the reservoir area lies in protecting the ecological environment and improving the carrying capacity of nature and environment. The ecological environment of the Three Gorges reservoir area is directly related to the benefits of the Three Gorges Project, directly affects the economic development of the whole upper reaches of the Yangtze River, and plays a decisive role in urban water use, farmland irrigation, flood control and South-to-North Water Transfer Project in the middle and lower reaches of the Yangtze River, thus making the sustainable development of the reservoir area concerned by the whole country and even the world. According to the present situation of ecological environment in the reservoir area and the regional conditions in the reservoir area, the following countermeasures are put forward to coordinate the relationship between economic development and ecological environment protection.

2. 1 Overall planning and comprehensive decision-making

The protection and construction of the ecological environment should be regarded as one of the major decisions of economic and social development, and as the basis and breakthrough of the large-scale development of the western region. In regional development, resource development and adjustment of industrial structure and productivity layout, we must adhere to the unity of economic development and environmental protection, rationally utilize natural resources, ensure sustainable economic development with ecological construction, and further promote ecological environment construction with economic development. Advocate the principle of sustainable development of "developing in protection, protecting in development, giving priority to prevention and giving priority to protection".

In addition, because the environmental protection and ecological construction in the Three Gorges reservoir area have a special position and great influence on the sustainable development of the entire Yangtze River Basin Economic Belt, it is suggested that the state should incorporate the environmental protection and ecological construction in the Three Gorges reservoir area into the national priority and key governance plan, and incorporate them into the national economic and social development plan as "three rivers and three lakes", giving priority, inclination and support in terms of project funds, capital investment, bank credit and utilization of foreign capital. At the same time, strengthen the collection, management and use of various special funds related to ecological environment construction to ensure investment.

2.2 Combined with the adjustment of industrial structure, we will intensify the control of pollution sources.

Combined with the adjustment of industrial structure and technological progress, measures are taken to control the total amount and concentration of pollutants discharged by enterprises and speed up the progress of industrial pollution source treatment within a time limit. Banning and closing heavy pollution sources, eliminating equipment and processes prohibited by the state, and promoting cleaner production; Enterprises with low technical content and serious pollution are prohibited from entering the reservoir area to prevent new pollution. At the same time, it can control the total amount and concentration of regional pollutants, regularly publish the monitoring results of each control section, and strictly assess its objectives. Secondly, strengthen the control of non-point source pollution. Non-point source pollution in the reservoir area mainly comes from pesticides, fertilizers and livestock manure, accounting for 40% of the total water pollution. The key to control non-point source pollution is to control soil erosion, improve product quality and utilization rate of pesticides and fertilizers, and vigorously develop green food.

2.3 Strengthen urban planning and rationally lay out new counties.

There are five counties in the Three Gorges reservoir area: Yunyang, Kaixian, Fengjie and Fengdu in Chongqing, and Zigui in Hubei. In urban construction, we must combine the relocation of immigrants, scientific planning and reasonable layout.

First, from the perspective of environmental protection, the layout of the city should consider the impact of topography, meteorology and hydrology on the environment. Urban industrial heavily polluted areas must be arranged in the downwind direction, and at the same time, we should pay close attention to the flow direction, velocity, sediment flow law and self-purification ability of rivers, so as to combine urban planning with basin planning and strengthen the protection of upstream and downstream water resources in the whole basin; Second, the internal layout of the city should also be conducive to environmental protection. For example, the urban layout with a single center and concentric circles and outward divergence makes the urban center farther and farther away from the surrounding natural environment, making it difficult to obtain fresh air.

In order to enter, the discharge of dirty air is blocked, which is not conducive to the natural adjustment of air. And take a multi-center group.

The belt structure divides the city into several areas, separated by green belts, which can alleviate the city.

The atmosphere, noise and heat pollution of the city play a positive role. At the same time, it should also support the construction of urban sewers

Treatment system and garbage harmless treatment system, rational layout of urban public green space, the construction of

New city with characteristic landscape in reservoir area.

2.4 Rely on scientific and technological progress to strengthen environmental protection and ecological construction in the reservoir area. First, according to the present situation and development trend of domestic sewage and industrial wastewater in the Three Gorges reservoir area, study and optimize the sewage treatment process suitable for environmental protection requirements and economic affordability. The construction of urban sewage treatment facilities at all levels in the reservoir area should adhere to the combination of large, medium and small, and adopt mature and reliable technology and scientific and reasonable treatment methods. According to the treatment scale, water quality characteristics, environmental function of receiving water body and local actual situation, after comprehensive technical and economic comparison, the treatment process should be optimized. Secondly, the treatment of domestic waste should also adhere to the principles of adapting to local conditions, feasible technology, reliable equipment, moderate scale and combining treatment with utilization, and rationally choose garbage treatment technologies such as sanitary landfill, incineration, composting and resource utilization to recycle and comprehensively utilize construction waste in flooded areas. Third, ecological construction should also continuously increase the scientific and technological content to ensure the quality and efficiency of ecological construction. First, it is necessary to study ecological adaptability, so that land, trees and grass can adapt. Counties (cities) should study the appropriate types, scales and reasonable structural layout of forest and grass vegetation construction according to the distribution laws and conditions of local forest and grass vegetation belts, determine the scientific forest and grass vegetation structure and corresponding technical support measures, and carry out scientific and technological research on ecological reconstruction in poor areas. Fourth, establish and improve the ecological environment prevention and monitoring system. Focusing on the key areas of ecological environment construction and soil and water conservation in the reservoir area, using modern information technology, establishing a comprehensive environmental monitoring center and

Network system. First of all, we can build four key monitoring networks in Fuling, Wanzhou, Wushan and Qianjiang and make them into databases.

The water quality, water ecology, major meteorological disasters and geological disasters in the region have been effectively monitored. Here,

On this basis, the corresponding prevention measures are formulated.

2.5 Implement system innovation and paid use of environmental resources.

The root of environmental problems lies in economic externalities. Economic policies can be used to internalize the economic externalities caused by the inconsistency of material interests into the economic analysis and decision-making process at all levels through market mechanisms, and pollution can be reduced by increasing pollution costs afterwards. Therefore, it can not only effectively restrain the polluter's discharge behavior and ensure the "polluter's burden", but also raise funds for the government to carry out centralized environmental control in the reservoir area, or use the funds for the research and development of cleaner production technologies. The environmental pollution in the reservoir area is very serious, largely because the paid use of environmental resources has not been implemented. For example, the sewage charges of enterprises are too low, and there is basically no charge for domestic sewage discharge and domestic garbage discharge of urban and rural residents. The economic externalities caused by polluters are not reflected in the production cost through the market, which directly aggravates the waste of resources and the deterioration of the environment. Therefore, the paid use of environmental resources is the basic idea to control environmental pollution in the reservoir area. For example, the downstream of the reservoir area can implement the charging policy of water resources reaching the standard. In February of 200 1 year, there was a precedent for purchasing water resources in China. In addition, it is necessary to improve the paid use mechanism of natural resources and environmental and economic policies, and strengthen the charging system for pollutants such as sewage and garbage.

2.6 Vigorously develop environmental protection industry

At present, the environmental pollution in the Three Gorges reservoir area is serious, there are many infrastructure and key projects to be built, and the environmental protection market capacity is large, which provides favorable conditions for the development of environmental protection industry. Developing environmental protection industry is not only the objective need of sustainable economic and social development, but also the inevitable choice to enhance the comprehensive economic strength and competitiveness of the Three Gorges reservoir area, and it can also provide industrial support for the transformation of environmental protection technology into productivity. Therefore, environmental protection industry should be listed as a priority development field and strive to become a pillar industry and a new economic growth point in the new century.

2.7 Strengthen the construction of environmental legal system and protect and build the ecological environment according to law.

First, strictly implement the relevant laws and regulations on environmental protection promulgated by the state, and promptly formulate and improve the targeted laws, regulations and technical regulations in the Three Gorges reservoir area. The second is to establish and improve the relevant systems of environmental protection and ecological construction, such as the sewage declaration and registration system, the sewage charge system and the environmental impact assessment system of construction projects. Third, we must seriously investigate and deal with acts that destroy the ecology and pollute the environment, and strengthen environmental protection.

Publicity and education of environmental protection laws and regulations, improve the awareness of the whole society to protect the ecological environment. 2.8 Actively carry out exchanges and cooperation to improve the scientific and technological level of ecological environment protection in the Three Gorges reservoir area. Through various international academic exchanges, technical fairs and exhibitions, we can learn the latest trends of environmental protection technology in the world and learn the mature experiences and methods of advanced countries in managing rivers, basins and large reservoirs. Through the introduction, digestion and localization of advanced technologies such as large-scale urban garbage, complete sets of sewage treatment equipment and ecosystem restoration, the gap with developed countries will be shortened. At the same time, we should actively carry out cooperation between the east and the west. The eastern part of China has been in the forefront of China's reform and opening up, and its economic strength and environmental protection technology level are much higher than those of the western part. It has gone through two processes: development and standardization, and accumulated quite rich experiences and lessons. Therefore, it is necessary to carry out extensive cooperation and international exchanges between the eastern and western regions, introduce advanced technologies, projects and high-quality talents, and strive to make the research level and applied technology of ecological environment in the reservoir area reach the international advanced level as soon as possible.