A methodology for the assessment of air quality in London and Bangkok
Abstract
Road transport has a major effect on the air quality in London and Bangkok. As an aid
to decision making to control and manage air pollution, air quality models are useful
tools and are now applied worldwide. This research aims to modify and adapt a
selected screening line source air quality model used in the UK for application in
Bangkok as general tools for air quality assessment. The emphasis is on models as an
aid to assess various scenarios involving traffic and emissions management. The
research also aims to assess air quality in the future years and to propose scenarios to
improve air quality in Bangkok. A screening air quality model, suited to this task, was
selected from amongst available alternatives: the CAR, DMIRB, LEZ, and GRAM
models. The DMRB and GRAM models fitted the requirements of the current
research. The GRAM model gave better performance than the DMRB model on the
predictions of NO2 and CO, except for PMIO in Bangkok. As the DMRB model
requires urban background to be specified whereas GRAM calculates the total
concentration including urban background levels, it was decided to select the GRAM
model and to adapt it from its current UK orientated formulation to make it applicable
to Bangkok. Various parameters were examined to identify the differences between
London and Bangkok conditions. Following this a new model for predicting NO2 and
PMIO was developed, called the Bangkok GRAM model, whose performance in
Bangkok was shown to be better than the UK GRAM model. Future projections were
also studied and indicated that the NO2 and PMIO levels in London will decrease in
future, but that exceedences will still occur. The introduction of more stringent
emissions controls and the early introduction of proposed vehicle emissions standards
are the additional measures expected to reduce UK urban emissions by up to 30%.
Under the current policy on emission reduction in Bangkok the model predicted little
decline in NO2 and PMIO concentrations at very busy roadside sites for up to 2010,
and continual increase in the future. Scenarios of additional measures are proposed.
The emission reduction approach gives significant reductions in NO2 and PM1o
concentrations in Bangkok. The model development has clarified where the main
uncertainties lie in urban modelling and emphasises the need to describe re-suspended
dust accurately, especially in Bangkok.
Publication date
2005Published version
https://doi.org/10.18745/th.14227https://doi.org/10.18745/th.14227