Study on the emission reduction effect of emergency management and control measures in Tangshan city, Hebei province, China

Abstract

Tangshan Air Heavy Pollution Emergency Command issued four orange alerts for air heavy pollution at 08:00 on January 4, 2018, 12:00 on January 26, 2018, 12:00 on December 10, 2018 and 12:00 on January 8, 2019, respectively. To evaluate the effectiveness of the four orange alert emergency measures in mitigating severe air pollution, this study employed the WRF-CMAQ air quality model to conduct numerical simulations. These simulations were based on the differences in industrial pollutant emissions under emergency measures. The analysis focused on air pollutant concentrations, including PM_2.5 and other pollutants, along with meteorological conditions, weather patterns, and air mass transport during the orange alert periods. Additionally, the study examined how emission reduction measures in Tangshan’s industrial affected PM_2.5 and other pollutant concentrations, and it assessed the effectiveness of the orange alert emission reductions. The results showed that the average PM_2.5 concentration was 0.74–5.01 times higher than that after the alert. During the four orange alerts, the influence of weather conditions and regional transport on pollution was different. The orange emergency management reduced the concentrations of PM_2.5, PM₁₀, SO₂, NO₂ and CO by 0.7 − 2.9%, 0.5 − 2.1%, 1.4 − 6.9%, 2.1 − 5.2%, and 5.6 − 10.1%, respectively. The orange alert suppresses the deterioration of severe air pollution, achieves the effect of pollutant peak reduction and deceleration, and slows down the accumulation rate of PM_2.5.