Environmental Effects: Characteristics of Environmental Problems in China s Large Cities and Their S

The main problems of China's urban environment include air pollution, water pollution, solid waste pollution, noise pollution, and soil pollution.

1. Air pollution.

Phenomena that result from human activities or natural processes causing certain substances to enter the atmosphere in sufficient concentrations and thereby endanger human comfort, health and welfare or the environment. Air pollution in China's cities is still dominated by soot, and the main pollutants are sulfur dioxide, carbon dioxide and soot. (as shown in the image below).

2. Water pollution.

Water pollution is water that pollutes the environment by reducing or losing the use value of water caused by harmful chemicals. China's cities and nearby rivers are still dominated by organic pollution, and the main pollution indicators are petroleum, permanganate, hail and ammonia nitrogen. (as shown in the image below).

3. Solid waste pollution.

Solid waste can be roughly divided into three types: domestic waste, general industrial solid waste and hazardous waste. China's municipal solid waste pollution includes industrial waste, construction waste and domestic waste. (as shown in the image below).

4. Noise pollution.

Since the Industrial Revolution, the creation and use of various machinery and equipment have brought prosperity and progress to human beings, but at the same time, more and more noise has been generated. The noise of most cities in China is at a moderate pollution level. (as shown in the image below).

5. Soil pollution.

Pollutants produced by human activities enter the soil and accumulate to a certain extent, causing the deterioration of soil quality, and then causing some indicators in crops to exceed the national standard, which is called soil pollution. Sources of soil pollution include the indiscriminate application of chemical fertilizers and pesticides, industrial wastewater and waste residues, as well as domestic sewage and garbage. (as shown in the image below).

The main problems in China's urban environmental management are urban garbage disposal, air pollution, and water environment pollution.

1. Urban garbage disposal.

With the acceleration of urbanization, the amount of urban waste is growing rapidly, and the gap between waste treatment capacity and waste generation is getting bigger and bigger, resulting in increasingly aggravated urban environmental pollution.

2. Air pollution problems.

The problem of urban air pollution in China is serious, especially pollution, which poses a huge threat to people's health. The main causes of air pollution are industry, transportation and other factors.

3. Water environment pollution.

Urban water pollution is one of the main problems of environmental pollution in China, and the lack of urban sewage treatment capacity and the aging of urban drainage pipe network have brought serious threats to the urban water environment.

The main manifestations of China's ecological environment are as follows:

Soil erosion is serious, and in the early days, the national soil erosion area was 1.16 million square kilometers. According to satellite remote sensing calculations in 1992, the area of soil erosion in China was 10,000 square kilometers, accounting for the entire national land area.

The areas with particularly serious soil erosion in China (from north to south) mainly include: the upper reaches of the Xiliao River, the Loess Plateau, the middle and upper reaches of the Jialing River, the lower reaches of the Jinsha River, the Hengduan Mountains, and some mountainous and hilly areas in the south.

Desertification is growing rapidly. China is one of the countries most affected by desertification in the world. The desert, Gobi and desertified land in the northern region has exceeded 1.49 million square kilometers, accounting for about 1.49 million square kilometers of the country's land area.

In the 80s, desertified land expanded at an average annual rate of 2,100 square kilometers. In the past 25 years, a total of 10,000 square kilometers of land have been lost. At present, about 59 million acres of farmland, 74 million acres of grassland, more than 2,000 kilometers of railways, and many towns, industrial and mining areas, and villages are threatened by desertification.

Answer]: B, C

a, the increase of carbon dioxide in the atmosphere produces a crude greenhouse effect, which causes global climate change; d, the city emits a large amount of heat, which makes the temperature higher than the surrounding area, produces more condensation nuclei and causes more rainfall in local areas; In item e, the industrial area emits a large amount of particulate matter, which produces more condensation nuclei and causes more rainfall in local areas.

Characteristics of the urban environment.

Due to the multiple impacts of human activities on the urban environment, the urban environment shows obvious characteristics.

1 The urban environment has the strongest human intervention character.

Because the city is the place with the most concentrated population, the most frequent social and economic activities, it is also the place where human intervention in the natural environment is the strongest and the natural environment changes the most. Except for the atmospheric circulation, large landform types, and the hydrological characteristics of major rivers, which basically remain in a natural state, other natural elements have changed to varying degrees, and such changes are usually irreversible. Urban architectural landscapes, urban roads, urban production and living facilities, etc., have redistributed precipitation, runoff, evaporation, and leakage in the city, and also caused great changes in the amount and quality of urban water and groundwater.

2 The environmental quality of a city is closely related to the social and economic development of the city.

Cities are complex artificial ecosystems composed of social-economic-environmental development, and economic and social development and environmental development are interdependent and interact. In order to develop the environment and meet the needs of the people's livelihood, society must also protect the environment in order to make better use of it. As a resource, the environment is the natural basis for human social and economic development, so environmental problems are essentially economic problems.

If economic development comes at the cost of polluting the environment, such development is fragile and will eventually limit production and constrain economic development. As the political, economic and cultural center of a certain geographical area, the social and economic activities engaged in by its residents are the main behaviors of the city, and the impact of these human behaviors on the environment is huge and cannot be ignored. Therefore, the size and nature of a city can often determine the quality of the urban environment, and purposefully adjusting the industrial structure of the city is the main means to improve the urban environment.

3. Most of the urban environmental pollution is compound multi-source pollution.

Cities are characterized by dense populations and a high concentration of industries. It carries out a large amount of material flow and conversion processing at all times, including all kinds of raw materials, finished products, daily necessities and waste, and consumes a lot of energy, such as coal, oil, electricity, etc. The division of labor within the city is becoming more and more detailed, and the functions of various systems are becoming more and more complex, and once a link fails or is out of proportion, it will cause the loss of pollutants.

In particular, under the circumstance of increasing industrial and transportation functions, the pollution nature of the urban environment has changed from a single domestic pollution in the past to multi-source pollution of industry and transportation, and the pollutants are complex, and the combined effect of various pollutants has aggravated the complexity of urban environmental problems. Cities are densely populated, and pollutants are the most serious harm to the human body's psychology and physiology, and the so-called "modern urban diseases" even infringe on the biological genetic changes of human beings.

4 Urban leakage and environmental problems can be improved by adjusting human behavior.

Human beings are intelligent, rational creatures. Since the problems of the urban environment are caused by human negligence, it is inevitable that the sick urban environment can be cured into a beautiful, tranquil and long-term ecological environment suitable for human beings through reasonable management, adjustment of human needs, desires and behavioral norms.

How to look at the quality of urban environment in the process of large-scale and large-scale rapid changes in China's urban structure and function.

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As the main energy source in China, coal is more widely used in production and life, and in the process of converting coal into heat energy, it releases a lot of pollutants, causing serious air pollution. Large quantities of pollutants are released into the air without being treated, leaving the atmosphere in serious exceedance. Coupled with the continuous growth of the number of private cars in recent years, a large number of high-emission vehicles have been put into use, adding a lot of burden to the atmosphere.

Pollution and shortage of water resources coexist with the increasing urban population and the rapid development of urban industry, water consumption is increasing day by day, but the discharge of domestic sewage and industrial wastewater is also very alarming, it is worth mentioning that many of these sewage and wastewater are discharged directly into rivers, lakes and seas without treatment, which directly pollutes the river water source. Thirty-six percent of the country's urban river sections are of inferior Class 5 water quality and have lost their use function. The water quality of large freshwater lakes (reservoirs) and urban lakes is generally poor, and more than 75% of the lakes have increased eutrophication, mainly caused by nitrogen and phosphorus pollution.

Due to the increase of urban population, people's awareness of water conservation has not yet been formed, and about 1 3 cities in China are in a state of water shortage all year round. In order to increase the occupancy rate, high-rise buildings have sprung up, and the area of green space is decreasing. More and more green spaces are being developed into factories, high-rise buildings, squares, etc., and the multiple environmental functions of urban green spaces are gradually being lost, which has become an acute environmental problem.

Noise pollution is widespread. Noise pollution such as construction noise, factory machine noise, and whistle noise has become one of the four major pollutants in China, seriously affecting people's life and health. In our country, more than 60% of the population is suffering from noise.

People who have been in the noise for a long time are very likely to cause tinnitus, deafness and other diseases, and they are also prone to mental tension and mood swings.

Answer]: A exhaust gas refers to the exhaust gas from the combustion of fossil fuels, industrial production, the combustion of garbage and industrial waste, and the driving of automobiles. There are many types of pollutants contained in exhaust gas, and their physical and chemical properties are very complex and toxic.

Exhaust gas polluting the atmosphere and Qingzhi environment is one of the most common and serious environmental problems in the world.