Study On Air Pollution Characteristics And Relations With Weather Conditions Of Lanzhou

Lanzhou is the first constructed industrial city since China found, the west area of the city which is the earliest built in nation is one of the most important petroleum chemical industryt basemen. Industrial pollution, life pollution emissions are heavy and the topography condition also against the spread of the atmospheric pollutants, the reasons are mentioned above make Lanzhou become the most serious air pollution city in our country and even in the world. Lanzhou is one of the first city which has found photochemical smoke pollution. In this paper, based on the analysis of energy structure, energy consumption and pollution sources distribution amount; and the spatial-temporal distribution characteristics of several main air pollutants, the relationship between air pollution and weather conditions of Lanzhou have been studied, and air pollutant concentration statistical forecast model was built. Main conclusions are as following:(1) The atmospheric pollution of Lanzhou city belongs to a typical coal-smoking pollution, in recent years display a trendy which change into coal-fired, motor vehicle exhaust and second dust mixed pollution.(2) The main pollutants concentration of Lanzhou in recent30years has a descending trend.(3) The main pollutant concentration of Lanzhou in different administrative areas have different characteristics, and they are closely linked with the climate conditions, people daily life behavior.(4) By analyzes the data of Lanzhou atmospheric boundary layer and atmospheric diffusion monitoring testing we come to conclusions that1) the pollution concentration’s daily changes is caused by cold front activities, which is a very important weather system, cold front before transit, pollutants concentration is higher, and gradually make a peak; after a transit, pollutant concentration of falling rapidly.2) Lanzhou post temperature inversion or low in winter morning and evening, mixing height is low, heavy polluted; mixing height is high, less polluted.(5) The type of the next day weather corresponding to the Lanzhou ground average pollution concentration is:cold type v-wind minimum; Transitional medium; Warm type v-wind highest. The ground weather type corresponding to the ground on day average Lanzhou pollution concentration:high pressure type front minimum; after high pressure is lower; south high pressure type is higher; after high pressure is highest type.(6) The pressure difference between Lanzhou and the upstream of Lanzhou has increased or the pressure gradient of Lanzhou increased, will be helpful for the pollutants spread, finally we have established three pollutants24h forecast equations of Lanzhou.