[Temporal and spatial distribution of air pollution in Shenzhen City during 2014-2016].

OBJECTIVE: To investigate spatial-temporal distribution characteristics of air quality indexes( AQI) in Shenzhen City and provide scientific basis for control of air pollution. METHODS: The monitoring data of AQI collected at the 19 monitoring posts in Shenzhen City from 2014 to 2016 were pooled and analyzed, and daily, seasonal and annual means of AQI at each monitoring post were forked out. The theory of spatial autocorrelation analysis was adopted in analyzing strength of the spatial autocorrelation and spatial clustering patterns of AQI. RESULTS: The median of AQI of Shenzhen City was50. 0, and the air quality level of Shenzhen City was level 2. PM_(2. 5) was the primary air pollutant in 2014, and O_3 was the primary air pollutant in 2015 and 2016 respectively. From the time distribution, the air quality in Shenzhen City was the worst in the winter but the best in the summer, and the air quality in night was worse than the day. Spatial autocorrelation analysis showed that there was positive spatial autocorrelation of AQI in Shenzhen. The global moran's I of AQI was 0. 167( Z = 2. 000, P < 0. 05), and the greary coefficient was 0. 801( Z = 1. 711, P < 0. 05). The local moran's I of AQI was 1. 027( P < 0. 05) in Guangming New District. The moran scatter plot of AQI in Guangming New District was in the first quadrant, and appeared to be in a high-high clustering pattern. The moran scatter plot of AQI in Yantian District was in the third quadrant, and appeared to be in a low-low clustering pattern. CONCLUSION: The air quality of Shenzhen City was better. PM_(2. 5) and O_3 were the primary air pollutant. It is necessary to emphasize and strengthen the prevention and control of air pollution in Winter, especially in several administrative districts of the northwest of Shenzhen City.