| With the development of national economy and continuously expanding of the city, air quality is intending to deteriorate in some medium and large cities. People are paying more attention to the air quality in their cities with the improvement of their living standard. The air quality directly affects people's health. Especially when the air quality is 4 grade, the air pollution over middle degree, it is very harmful to people's work, life and health, In some cities, there have been many studies about the meteorological factors that affect the air quality, as well as the work of air quality forecast. But in Rizhao city, there are little studies about the change of air quality, its related factors and prediction. Almost nothing has been done on air quality prediction and operation system, fit in Rizhao city. In this article, we do following work by using the air pollution data from Rizhao air quality observation station and the related meteorological data: Analysis the spatial and temporal distribution characteristics of the air pollutant; Study the meteorological factors which affect the distribution of pollutant; Set up the numerical prediction model (CAPPS) for Rizhao City; Apply step-wise regression equation to the pollutant concentration forecast; Try to integrate the numerical forecast and statistical result according to their differentweight factor; Study the air pollution passive tend forecast in RiZhao city, based on the surface weather situation and related meteorological factors; Conclude the ratio of the meteorological factors and weather situation to pollution index; We can get much better result by correcting the forecast with weather situation and other weather factors especially the capability of predicting the days with medium or worse pollution. The precision prediction with weighted method in the new urban is 6% more than that with statistical method. It is much better in the old town, more than 15%. After the correction, based on the weather situation and meteorological factor, the forecast precision is much higher than that with the former method, increasing 6% in new urban and 2% in old urban. In the mean time, missing forecast with the low or worse air pollution days can be avoided. But it can not completely avoid vacant forecast. This method is easy and effective, and can be applied to predict the urban air quality .Set up an automatic and stable air quality forecast operation system, which integrated the process of data transferring, exchanging, numerical forecast, correcting result and making and distribution of the forecast.The urban pollutant in Rizhao city is mainly the particulate matter(PM10). The probability of low pollution days is 12%. The air pollutantshows obvious change with seasons. The time with lower level pollutionall occurred in the half year of winter (mainly in January-April). The timewith higher level pollution occurred in winter and spring. The second is in autumn. In summer, the air quality is fine with almost none air pollution. The higher pollution index occurred in spring (March-April) because of the dry surface in the up region and the dust caused by the cold air and frequently strong wind.The annual mean concentration distribution of the pollutant in Rizhao shows distinct regional characters. Three kinds of pollutant concentration in the new urban are lower than that in the old urban.The surface weather systems affect the pollutant concentration greatly. There are two kinds of circulation types: the easily diffusing one and the uneasily diffusing one. The easily one includes the front of the cold high pressure, low pressure or low pressure belt, the rear of the negative trough, etc. With the affect of the easily diffusing systems, the pollutant concentration decreases greatly. The uneasily diffusing systems include the landform trough, the area near to the center of the cold high pressure, weak negative trough and negative trough. With the affect of the uneasily systems, the pollutant concentration incre... |
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