STUDY ON GREY PREDICTION OF NO_2 CONCENTRATION IN ATMOSPHERE IN ZHENGZHOU AND IT'S POLLUTION

NO 2 is a common air pollutant in many Chinese cities for its forming of light chemical gas, harmful to the environment as well as to people's health. It is just for this reason that it has become an important issue to analyze and monitor the concentration of NO 2 in hope for better protecting our environment. Seeing such an urgent need, the present paper has made a continuous observation and recoding for years of NO 2 concentrations in Zhengzhou, the capital of Henan Province, making clear of the general trend of NO 2 concentration change in the city. The daily and annual mean concentration of NO 2 in Zhengzhou has been lowering these years, but the changing trend of the maximum value and the mean value remain unstable. To make a better study of the factors affecting the changing pattern of NO 2 concentration, the author of this paper has adopted the Grey Relativity Analysis approach and the Grey System theory. Furthermore, the effect degree of each factor has also been quantified. In order to predict NO 2 concentration in the atmosphere, we have come up with a gray dynamic model GM (1,1), too. Our investigation reveals that: 1) The foremost factor affecting the concentration of NO 2 is the ratio of the natural gas popularization of home cooking; 2) The concentration of NO 2 in the atmosphere has been proved decreasing year by year with 0.043 mg·m -3 in 2002. 3) Air pollution in Zhengzhou is typical of coal smog pouring. With the advance of the central heating system in winter and the popularization of home's nature gas, the pollution caused by NO 2 will soon be reduced dramatically in the city.