The Chishui River Valley is a microscale ecology-preservation area with industrial clusters.The significance of evaluating vehicular emissions has been gradually highlighted with the rapid development of the local tra...The Chishui River Valley is a microscale ecology-preservation area with industrial clusters.The significance of evaluating vehicular emissions has been gradually highlighted with the rapid development of the local transportation and tourism sectors.This study provides the first estimates based on both bottom-up and top-down approaches.The annual total emissions of CO,NOx,hydrocarbons(HC),PM10,and PM2.5 in 2019 were 347.8,189.6,46.3,6.9,and 6.3 Mg,respectively.Trucks contributed the most(55%)to the NOx emissions,followed by heavy-duty passenger vehicles(26%).In contrast,light-duty passenger vehicles and motorcycles generated 75%of the HC emissions.The superior accuracy of highly spatial and temporal bottom-up estimates versus top-down estimates is validated by the similar variation trends of hourly emission intensities and enhanced concentrations relative to background observations for both NOx and CO,with Pearson correlation coefficients between the intensities and concentrations ranging from 0.79 to 0.85.Historical HC emissions peaked in 2013,followed by a sharp decline in 2014 and a continuous rise since then,whereas NOx emissions have kept increasing since 2010.These indicated the necessity and urgency of effective vehicular emission mitigations.Based on scenario analysis,traffic restrictions combined with upgrading the emission standards of admitted vehicles will possess huge emission reduction potentials.Future recommendations about establishing a low emission zone in the valley and supporting policies were introduced.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42061130213 and 41822505)the special fund from the State Key Joint Laboratory of Environment Simulation and Pollution Control(No.20L01ESPC)and the Tsinghua University-Toyota Research Center.Huan Liu was supported by the Royal Society of the UK through the Newton Advanced Fellowship(No.NAF\R1\201166)and the Tsinghua University Initiative Scientific Research Program(No.2019Z02CAU).
文摘The Chishui River Valley is a microscale ecology-preservation area with industrial clusters.The significance of evaluating vehicular emissions has been gradually highlighted with the rapid development of the local transportation and tourism sectors.This study provides the first estimates based on both bottom-up and top-down approaches.The annual total emissions of CO,NOx,hydrocarbons(HC),PM10,and PM2.5 in 2019 were 347.8,189.6,46.3,6.9,and 6.3 Mg,respectively.Trucks contributed the most(55%)to the NOx emissions,followed by heavy-duty passenger vehicles(26%).In contrast,light-duty passenger vehicles and motorcycles generated 75%of the HC emissions.The superior accuracy of highly spatial and temporal bottom-up estimates versus top-down estimates is validated by the similar variation trends of hourly emission intensities and enhanced concentrations relative to background observations for both NOx and CO,with Pearson correlation coefficients between the intensities and concentrations ranging from 0.79 to 0.85.Historical HC emissions peaked in 2013,followed by a sharp decline in 2014 and a continuous rise since then,whereas NOx emissions have kept increasing since 2010.These indicated the necessity and urgency of effective vehicular emission mitigations.Based on scenario analysis,traffic restrictions combined with upgrading the emission standards of admitted vehicles will possess huge emission reduction potentials.Future recommendations about establishing a low emission zone in the valley and supporting policies were introduced.
