Wildfire Smoke Transport and Air Quality Impacts in Different Regions of China

Lifu Shu,Yongqiang Liu,Fengjun Zhao,Qi Zhang

doi:10.3390/atmos11090941

Abstract

The air quality and human health impacts of wildfires depend on fire, meteorology, and demography. These properties vary substantially from one region to another in China. This study compared smoke from more than a dozen wildfires in Northeast, North, and Southwest China to understand the regional differences in smoke transport and the air quality and human health impacts. Smoke was simulated using the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) with fire emissions obtained from the Global Fire Emission Database (GFED). Although the simulated PM2.5 concentrations reached unhealthy or more severe levels at regional scale for some largest fires in Northeast China, smoke from only one fire was transported to densely populated areas (population density greater than 100 people/km2). In comparison, the PM2.5 concentrations reached unhealthy level in local densely populated areas for a few fires in North and Southwest China, though they were very low at regional scale. Thus, individual fires with very large sizes in Northeast China had a large amount of emissions but with a small chance to affect air quality in densely populated areas, while those in North and Southwest China had a small amount of emissions but with a certain chance to affect local densely populated areas. The results suggest that the fire and air quality management should focus on the regional air quality and human health impacts of very large fires under southward/southeastward winds toward densely populated areas in Northeast China and local air pollution near fire sites in North and Southwest China.

Highlights

Wildfires have increased in many regions of the world with a large number of devastating wildfires in recent years [1,2,3,4,5,6,7]
The results suggest that the fire and air quality management should focus on the regional air quality and human health impacts of very large fires under southward/southeastward winds toward densely populated areas in Northeast
(1) Case 1: Smoke was transported from the fire site to densely populated areas in Northeast China with a potentially large human health impact; (2) Case 2: Same as Case 1 except with a potentially small human health impact

Summary

Introduction

Wildfires have increased in many regions of the world with a large number of devastating wildfires in recent years [1,2,3,4,5,6,7]. About two dozen extremely large fires occurred in the western United States in 2017 and 2018 with totally burned areas of about 22 thousand km (2.3 million hectares (hm2 )). The 2018 Camp Fire in northern California damaged nearly 19 thousand structures and led to 85 deaths. The 2019–20 Australia bushfires burned 160 thousand km (16 million hm2 ) lands, leading to losses of over 3000 houses and 33 lives. The 2019 Amazon fires burned about 1500 km (150 thousand hm ). The 2017 Portugal fires burned 5000 km (0.5 million hm2 ) with a loss of 119 human lives and the 2018 Greece Mati fires caused a loss of 99 people. In Russia, 25 thousand km (2.5 million hm2 )

Methods

Results

Discussion

Conclusion