Beijing Environmental Protection Bureau released the 2017 annual air quality report, pollutants have been improved

In 2017, through the concerted efforts of the whole city, the four major pollutants including fine particulate matter (PM2.5) in Beijing all improved year-on-year, with the simultaneous improvement of regional air quality and overall favorable weather conditions. Among them, PM2.5 year The average concentration is 58 micrograms/m3, and the mission goal of the National Air Pollution Prevention and Control Action Plan (referred to as the “Ten Atmosphere”) has been fulfilled. The annual average concentration of sulfur dioxide (SO2) dropped to single digits for the first time. 1. The overall situation and characteristics of 2017 In 2017, the annual average concentration of PM2.5 in Beijing was 58 μg/m3, a decrease of 20.5% from the previous year; compared with 90 μg/m3 in 2013, it was 32 μg/m3. The drop reached 35.6%, fulfilling the target of about 60 micrograms/cubic meter set by the national 'Atmospheric Ten Measures'. In 2017, the annual average concentrations of SO2, nitrogen dioxide (NO2), and inhalable particulate matter (PM10) in Beijing were 8 micrograms/m3, 46 micrograms/m3, and 84 micrograms/m3, respectively, which were improved year-on-year, compared with 2016 Year-on-year declines were 20.0%, 4.2%, and 8.7% respectively. Please click here to enter the picture description. Figure 1 Changes in the annual average concentration of various pollutants from 2016 to 2017. In 2017, Beijing’s SO2 reached the national standard (60μg/m3); NO2 exceeded the national standard (40μg/m3)15 %; PM10 exceeds the national standard (70μg/m3) by 20%; PM2.5 exceeds the national standard (35μg/m3) by 66%. In 2017, the number of good days in Beijing was 226 days, an increase of 28 days compared with 2016; the number of heavy pollution days was 23 days, which was 16 days less than 2016. Please click here to enter the picture description. Figure 2 The distribution of air quality at various levels in 2017 is analyzed from the daily cumulative concentration changes. In January 2017, the air pollution diffusion conditions were unfavorable. The cumulative concentration of PM2.5 reached 116 μg/m3, and the concentration rebounded year-on-year More than 70%; the later concentration showed the characteristics of continuous decline, starting from September, the cumulative concentration of PM2.5 reached 60 micrograms / cubic meter, and continued to decline in autumn and winter. In 2017, the monthly average concentration of PM2.5 in 9 months was the lowest level in the same period in the past 5 years. From the analysis of air pollution diffusion conditions, the weather conditions in 2017 are generally favorable, which are reflected in the low frequency of temperature inversions, relatively dry air, and high frequency of northerly winds. Especially in the fourth quarter, the cold air activity was frequent, the temperature was low, and heavy air pollution occurred 4 times, resulting in 5 days of heavy pollution, which was significantly lower than the level of the previous two years. With the continuous reduction of air pollution reduction and the combination of favorable atmospheric diffusion conditions, Beijing's air quality has improved significantly in 2017. 2. Changes in major pollutants from 2013 to 2017 Compared with 2013, the annual average concentration of major pollutants in Beijing decreased significantly in 2017, and SO2, NO2, PM10, and PM2.5 decreased by 70.4%, 17.9%, and 22.2, respectively. %, 35.6%; among them, SO2 has the largest decline, and the annual average concentration in 2017 fell to single digits for the first time. Please click here to enter the picture description. Figure 3 Changes in the annual average concentration of various pollutants from 2013 to 2017? From 2013 to 2017, the number of air quality compliance days in Beijing increased significantly, with 176 days in 2013 and 176 days in 2017. This is 226 days, an increase of 50 days. Among them, the number of first-level excellent days increased from 41 days in 2013 to 66 days in 2017, an increase of 25 days. Please click here to enter the picture description. Figure 4 The distribution of air quality levels in days from 2013 to 2017. Please click here to enter the picture description. Figure 5 The distribution of PM2.5 air quality levels in 2013-2017. Air quality in Beijing, 2013-2017 The number of pollution days were 58, 47, 46, 39, and 23 days, showing a characteristic of decreasing year by year; the number of days of heavy pollution decreased by 35 days in five years, and the incidence of heavy pollution was significantly reduced. In the five years from 2013 to 2017, the concentration of PM2.5 in all regions of Beijing has decreased year by year, and the decline is significant; in 2017, the concentration level in each region has been significantly lower than in 2013, and the overall spatial distribution is still characterized by high in the south and low in the north. The concentration gap is reduced. Please click here to enter the picture description Figure 6 The spatial distribution of PM2.5 concentration in Beijing Please click here to enter the picture description Figure 7 The gross national product, permanent population, total energy consumption, motor vehicle ownership and various items in the past two decades Pollutant Concentration Since 1998, while Beijing has been developing rapidly in economy and society, the concentrations of major air pollutants monitored have shown a continuous decline. However, the current pollutants such as PM2.5, PM10, and NO2 still exceed national standards, indicating that Beijing The improvement of air quality will still be a long-term process.　3. The overall overview of the 2013-2017 Clean Air Action Plan. First, the engineering-based emission reduction measures are unprecedented. On the basis of implementing the national “Ten Atmospheres” and “Required Actions” without compromising, the city has successively issued the “Beijing Clean Air Action Plan for 2013-2017” and “Beijing Implementation of the “Beijing-Tianjin-Hebei Air Pollution Prevention and Control Measures (2016- 2017)> Implementation PlanThe optimization and promotion of transportation structure shall coordinate and promote the prevention and control of air pollution. In the past five years, the total amount of clean energy transformation of coal-fired boilers, rural scattered coal treatment, adjustment and withdrawal of enterprises that do not conform to the functional positioning of the capital, polluting enterprises, and scrapping out of old motor vehicles has been about the sum of the past ten years. Resolutely implemented hard measures Hard task, to maximize 'human effort'.