Overnight, the Yangtze River Delta region also fall into the "decahedron haze volts." December 4, Nanjing this year for the first time to start the highest level of air pollution red alert. Shanghai is also the first release second high-level haze orange warning signal since 2011.
Yangtze River Delta area into a large haze pollution, very simple objective factors: weather conditions are very unfavorable. Meteorology tube this is called "static stability of the weather." It can cause the air in the horizontal and vertical directions on liquidity is very small, atmospheric dispersion conditions of pollutants becomes very poor. Fog itself also caused traffic jams, forcing the vehicle idling or running at low speed, exhaust emissions further increases. Deterioration of air quality in this case it is not hard to understand.
Yangtze River Delta static stability should be said that the weather is relatively rare. For example, in January 2013 more than half of China into a haze days, almost the entire territory of Jiangsu Province has been spared, because of the involvement of such scholars said "relatively rare in the past decade," the weather. During that pollution, haze in Beijing, Tianjin reached 5 times 26 haze Jiangsu duration of up to 2 times 18 days.
But compared've seen all kinds of haze days, the people of Beijing and other places, the severe air pollution incidents apparently shocked the residents of the Yangtze River Delta. After witnessing some of my local friends Shanghai PM2.5 pollution Biao value increased to 300, he has been complaining SNS circles Tucao. This repeatedly burst through pollution index table (over 500) of the Beijing People's opinion, it is difficult to understand. Clearly, the Shanghai friends still can not adapt to this bad air quality level almost equal to the capital.
Shanghai annual overall air quality is significantly better than Beijing, Yangtze River Delta, the annual air quality is better than Beijing, Tianjin region, which is an objective of the present situation. Whether it is to compare two values of annual average concentration of PM2.5 pollution or calculate the number of days between the two places, we can come to such a conclusion.
But this is not because the pollutant emissions than Shanghai or Beijing or Beijing, Tianjin and the Yangtze River Delta small. Such as Shanghai, pollutant emissions every year and Beijing is actually a draw. On the part of the air pollutant index, Shanghai and even far more than Beijing. I have been compared to the two annual State of the Environment, sulfur dioxide and nitrogen oxide emissions Shanghai in recent years to reach more than 2 times Beijing emissions. Another important vehicle exhaust pollution, Shanghai favorably. Beijing is the country's largest city vehicle fleet, more than 5 million. However, Shanghai is the country's most dense urban vehicle, equivalent to 23 times the national average.
Shanghai's air quality in Beijing is better than reason, we need thanks to its weather and geographical conditions of superiority. Beijing is surrounded by mountains, pollutant emissions and virtually impossible to north west Beijing every year drought, nearly a decade with an average annual rainfall of less than 500 mm. These are not conducive to the diffusion of air pollutants natural and geographical conditions, air pollution in Beijing is a natural disadvantage. In contrast, Shanghai is the seat of rainy city, with an average annual rainfall of over 1000 mm, one year more than one hundred days to have all the rain. Frequent rain can effectively maintain the cleanliness Shanghai fresh air.
Not only is rain, wind blowing over the coast of Shanghai's air quality also have added benefits. Summer, from the East China Sea to Shanghai will continue blowing winds, which directly means that clean air will bring the East China Sea. And windier, the improvement of air quality in Shanghai is more obvious. Shanghai only exception winter wind blowing, the wind from the north in winter scraping inland areas may give Shanghai bring pollutants. For example, like this haze days after the North fired into the heating period, it brings more wind and pollutants.
In addition to conventional industrial pollution, car exhaust, coal-fired heating and other pollution emissions, the Yangtze River Delta is also facing some different from Beijing, Tianjin and pollution problems. This trouble in certain days. Shandong, Anhui, Jiangsu and other places in rural areas have been straw burning habits. Wind from the northern inland areas with straw burning of large quantities of smoke may also increase the PM2.5 pollution in Yangtze River Delta area of the city. Nanjing autumn season in the past few years have repeatedly exposed the problem.
Overall, however, the Yangtze River Delta with Shanghai city to avoid haze days obvious advantages: timing and location. But faced with extreme conditions, this advantage is not enough to make their own island. Once the loss of God's care, but also inevitably become overnight Silent Hill. Governance haze, every city and region have the responsibility, have a long way to go.
8 Editor's note: According to People's Daily, said the good news is that the upcoming cold air to disperse the but there is a bad news ...... cold air on the 8th to come.
(Figure questions from Xinhua)
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