Transport

Modelling of the transport sector

Road transport

The road transport sector is an important source of NOx and fine particulate matter, PM10, affecting urban air quality and human health; and of greenhouse gases - CO2 and also some N2O. NOx chemistry also leads to ozone formation, and nitrate aerosol; and enables deposition of nitrogen compounds contributing to acidification and eutrophication of natural ecosystems.

BRUTAL Transport sub model The BRUTAL transport sub-model  (Background, Roads and Urban Transport:modelling of Air quality and Limit values) estimates emissions and road-side concentrations for the  whole UK road network, using data  assembled on traffic flows and speeds and vehicle mixes combined with emission factors compiled by AEA and used in the National Atmospheric Emissions Inventory, NAEI. Separate calculations are undertaken of the background concentrations, and the road-side increments superimposed for comparison with air quality limit values.

The BRUTAL model is being applied to future scenarios, and simulation of the effectiveness of both international and national  measures and technological improvements to reduce vehicle emissions; and of local and non-technical measures affecting traffic volumes.

Recently, emissions of CO2 and N2O have been added to BRUTAL alongside those of PM10 and NOx, so that simultaneous effects on greenhouse gases can be taken into account.

Relevant Publications

  • Oxley T, Elshkaki A, Kwiatkowski L, Castillo A, Scarbrough T, ApSimon H, 2012, Pollution abatement from road transport: cross-sectoral implications, climate co-benefits and behavioural change,Environmental Science & Policy, 19-20, pp16-32
  • Oxley T, Valiantis M, Elshkaki A, et al, Background, Road and Urban Transport modelling of Air quality Limit values (The BRUTAL model), Environmental Modelling & Software, 2009, Vol:24, Pages:1036-1050, ISSN:1364-8152(abstract publication doi)

Shipping

Ewmissions from shipping are of growing importance. With the major effort to control land-based emissions of SO2 and NOx in Europe, those from shipping are expected to soon exceed those from land-based sources. Importance is therefore attached to reduce emissions from shipping, and the investigation of environmental advantages of transporting  by ship if this avoids transport by other means.

Currently assessment of the impact of shipping emissions is based on emissions compiled by ENTEC , and atmospheric modelling with the EMEP  Eulerian model. This has a coarse spatial resolution of ~50x50 km across Europe. In future it is hoped to use better spatial resolution to investigate impacts on the UK in more detail, especially in coastal areas; and explore the relative merits of further action to curb UK emissions as compared with those from shipping in the neighbouring sea areas.

Relevant Publications

  • Dore, A. J., Vieno, M., Tang, Y. S., Dragosits, U., Dosio, A., Weston, K. J. & Sutton, M. A., 2007, Modelling the atmospheric transport and deposition of sulphur and nitrogen over the United Kingdom and assessment of the influence of SO2 emissions from international shipping. Atmospheric Environment, 41 (11), 2355-2367                                          

Airports

Studies have also been undertaken of air quality in areas surrounding airports, emphasizing the role of emissions from associated road transport superimposed on other activities and infrastructure in the surrounding area.

PhD thesis: Fernando Farias (2005) Air pollution exposure and integrated assessment modelling round London's Heathrow airport.
PhD thesis: Sukaina Al Wasity (2012) Air Quality Studies at Abu Dhabi International Airport: