Analysis of the Characteristics of the Haze in Recent 3 Decades in Chengdu

Abstract

It is valuable to study the characteristics of haze change to make good efforts to control air pollution. The haze days in recent 3 decades in Chengdu were counted by 14 hour method, coming to the following results: 1) the number of haze days in Chengdu has decreased and then increased in the recent 3 decades; 2) the number of haze days in autumn and winter accounts for 70% of the year-round number. The spatial distributed characteristic of haze in Chengdu is that it is rare in northwestern Chengdu and common in southwestern Chengdu. Compared with Dujiangyan, the environmental background field of Chengdu, haze trends to become more serious in Shuangliu; 3) according to the comparative analysis on the AQI of 2013 and number of haze days, the methodologically-counted haze days correspond to moderate pollution weather, and this is well reflected in autumn and winter. It is susceptible to the rainfall system in summer; 4) the primary pollutant in Chengdu is PM2.5, followed by PM10. The climatic background is inimical to pollutant diffusion. Besides, the expansion of urban area and the change of people’s lifestyle are significant causes of the increase in the number of pollution days.