The Yangtze River and the Yellow River are urgently needed, and the famous rivers are the situation

Due to people's insufficient prediction of the negative impact of highly developed industry, it has led to three major global crises: resource shortage, environmental pollution, and ecological destructionHuman beings are constantly emitting pollutants into the environment.

However, due to the effects of diffusion, dilution, redox, biodegradation, etc. of the atmosphere, water, soil, etc. The concentration and toxicity of pollutants naturally decrease, a phenomenon called environmental self-purification. If the emitted substances exceed the self-purification capacity of the environment, the quality of the environment will undergo adverse changes, endangering human health and survival, which occurs environmental pollution.

There are various classifications of environmental pollution:

According to environmental elements: air pollution, water pollution, soil pollution.

According to human activities, it is divided into industrial environmental pollution, urban environmental pollution, and agricultural environmental pollution.

Environmental pollution will cause direct damage and impact on the ecosystem, such as desertification, deforestation, and indirect harm to the ecosystem and human society, and sometimes the harm of this indirect environmental effect is greater than the direct harm caused at that time, and it is more difficult to eliminate. For example, the greenhouse effect, acid rain, and ozone layer depletion are environmental effects derived from air pollution. This kind of environmental effect derived from environmental pollution has a lag, and is often not easy to detect or predict at the time of pollution, but once it occurs, it means that environmental pollution has developed to a very serious point.

Of course, the most direct and easily felt consequence of environmental pollution is to reduce the quality of the human environment and affect the quality of human life, physical health and production activities. For example, air pollution in cities causes air pollution, and people's morbidity increases. Water pollution deteriorates the quality of the water environment, and the quality of drinking water sources generally declines, threatening people's health, causing premature birth or malformation of the fetus. Serious pollution incidents not only cause health problems, but also social problems.

With the intensification of pollution and the improvement of people's environmental awareness, the number of disputes and conflicts among people caused by pollution is increasing year by year.

At present, environmental pollution problems have occurred to varying degrees in the world, and the aspects with global impact include atmospheric environmental pollution, marine pollution, and urban environmental problems. With the globalization of the economy and the world, environmental pollution is also increasingly internationalized, and the transboundary transfer of hazardous wastes in recent years is a prominent manifestation in this regard.

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In 1995, the Yellow River was cut off for 121 days, with a section of 700 kilometers. Experts predict that if this development continues, it is a foregone conclusion that the Yellow River will become an inland river. The closure of the Yellow River will create a serious ecological crisis.

Lop Nur in northwest China finally dried up in the 70s of this century.

"Bitter water" main stream: Nearly 40% of the river section has basically lost its water function, and more than 1.2 million citizens can only drink bitter water.

At the beginning of this year, the Yellow River Basin Water Resources Protection Bureau organized a team of experts to conduct a quantitative analysis of the status and hazards of water pollution in the Yellow River, and found that nearly 40% of the water quality of the main stream of the Yellow River was classified as inferior. With the economic development, the discharge of waste water in the Yellow River basin has doubled compared with the 80s of the last century, reaching 4.4 billion cubic meters, and pollution incidents continue to occur. Most of the tributaries in the upper reaches of the Yellow River are polluted to varying degrees, while the water quality of almost all the tributaries in the middle and lower reaches has been in a state of inferior class 5 for many years, and the tributaries have become "sewage rivers".

According to the statistics of the Gansu Provincial Environmental Protection Bureau, the Gansu section of the Yellow River discharges 100 million tons of wastewater every year, of which the discharge of domestic sewage has reached 100 million tons, accounting for the total wastewater discharge. The Yellow River flows through four cities in Gansu, and only Lanzhou has four sewage treatment plants with a daily treatment capacity of only 10,000 tons. Moreover, the sewage treatment fee levied by Lanzhou is only one yuan per cubic meter, and the sewage treatment fee collected by the city can only maintain the operation of a sewage treatment plant with a daily treatment capacity of 100,000 tons.

Zhao Weimin, director of the Gansu Provincial Environmental Protection Bureau, said that as the only provincial capital city where the Yellow River passes through the city, Lanzhou currently has only one sewage pipe network penetration rate. The small sewage treatment and collection capacity is far from sufficient to deal with the increasing amount of urban sewage discharge, resulting in a dense network of sewage pipes and ditches along the Yellow River, and a large amount of domestic sewage is directly discharged into the Yellow River.

Since 1972, the Yellow River has often been cut off. There are many reasons for the interruption of the flow, which can be summarized as follows:

1.Global warming - With the intensification of global warming in recent years, on the one hand, the evaporation of rivers has increased significantly, and on the other hand, the melting of glaciers in the upper reaches of spring and summer absorbs a large amount of heat, resulting in lower than usual local temperatures in the interior, reducing the temperature difference between the inland and the ocean, and then causing the monsoon to weaken, and the lack of water vapor brought by the monsoon from the sea surface to the inland. Although global warming has increased the flow of upstream water by melting glaciers, it has not offset the effects of increased evaporation and weakening of the monsoon.

As a result, the amount of water in the middle and lower reaches is decreasing year by year.

2.Vegetation destruction - The Loess Plateau has serious vegetation destruction, the land lacking vegetation conservation is gradually desertified, the evaporation becomes high, and the dry groundwater needs to be continuously absorbed and flowed through the river to replenish.

3.Backward irrigation methods -- most of the middle and upper reaches of the Yellow River flow through economically underdeveloped areas and poor areas, lacking water-saving irrigation technology and funds, and most of them are flooded, and the Yellow River is seriously wasted.

The upper reaches belong to the arid and semi-arid areas, the precipitation rate is low, the middle reaches are the main recharge areas, but the soil erosion is serious and the seasonal changes are large, and the downstream basin area is small and the recharge is small.

The population in the basin is growing rapidly, and the population growth rate is far outpacing the food growth rate;

In recent decades, with the development of society, the water consumption of industries and cities along the Yellow River has been increasing, and the irrigation area of the Yellow River has been expanding.

The regulation capacity of reservoirs is low, and the management of water resources is not uniform;

The water fee is low, and the low water price cannot arouse people's awareness of water conservation, and the waste of water in industry and agriculture is huge;

Environmental pollution has dramatically reduced the utilization rate of the Yellow River's water.

There are many reasons for the water pollution in the Yellow River Basin, which can be summarized as follows. (1) Some large and medium-sized cities in the basin are located near the river, and some large industrial and mining enterprises are also distributed along the river. At the beginning of the 90s, there were 20 million people in cities and towns in the basin, of which more than 2 3 were concentrated in these cities and industrial and mining areas.