Analysis of the impact of inhomogeneous emissions in the Operational Street Pollution Model (OSPM)

Semi-parameterized street canyon models, as e.g. the Operational Street Pollution Model (OSPM^®), have been frequently applied for the last two decades to analyse levels and consequences of air pollution in streets. These models are popular due to their speed and low input requirements. One often-used simplification is the assumption that emissions are homogeneously distributed in the entire length and width of the street canyon. It is thus the aim of the present study to analyse the impact of this assumption by implementing an inhomogeneous emission geometry scheme in OSPM. The homogeneous and the inhomogeneous emission geometry schemes are validated against two real-world cases: Hornsgatan, Stockholm, a sloping street canyon; and Jagtvej, Copenhagen; where the morning rush hour has more traffic on one lane compared to the other. The two cases are supplemented with a theoretical calculation of the impact of street aspect (height / width) ratio and emission inhomogeneity on the concentrations resulting from inhomogeneous emissions. The results show an improved performance for the inhomogeneous emission geometry over the homogeneous emission geometry. Moreover, it is shown that the impact of inhomogeneous emissions is largest for near-parallel wind directions and for high aspect ratio canyons. The results from the real-world cases are however confounded by challenges estimating the emissions accurately

On the parameterisation of the urban atmospheric sublayer in meteorological models

International audienceThe increased resolution of numerical weather prediction models allows nowadays addressing more specifically urban meteorology and air pollution processes and forecasts. This has triggered new interest in modelling and describing experimentally the specific features and processes of urban areas. Recent developments and results performed within the EU-funded project FUMAPEX on integrated systems for forecasting urban meteorology and air pollution are reported here. Issues of optimum resolution, parameterising urban roughness and surface exchange fluxes and the role of the urban soil layers are addressed with advanced meso- or sub-meso meteorological models. Recommendations, especially with respect to advanced urban air quality forecasting and information systems, are given together with an assessment of the needed further research and data

La modelación y la gestión en el mejoramiento de la calidad del aire

This paper provides a review of international trends used in connection with modeling and management of urban air quality. According to specialized literature on this topic, the most common actions are dose-response evaluation, modeling, monitoring, emission control, and planning. The methodology implemented consisted of a procedure for managing measures to control atmospheric pollutants from fixed and mobile sources in order to pursue initiatives aimed at minimizing the risks posed by air pollution to health and the environment. This resulted in an atmospheric emission inventory, which can be used for improving air quality management efforts, and three different kinds of software applications that can be used as technical support tools for receiving, analyzing, and monitoring data. As a conclusion, the procedure for the Environmental Territorial Authority (ETA) to manage measures for controlling atmospheric pollutants from fixed and mobile sources is a promising management tool aimed at minimizing the health and environmental risks associated with air pollutionEl artículo analiza las tendencias internacionales utilizadas sobre la modelación y la gestión implementada en el manejo de la calidad del aire urbano. La literatura especializada establece que las acciones más empleadas son la evaluación dosis-respuesta, modelación, monitoreo, control de emisiones y planificación. La metodología que se implementó fue un procedimiento para la gestión de las medidas de control de contaminantes atmosféricos de fuentes móviles y fijas para adelantar una gestión, orientada a minimizar los riesgos que presenta la contaminación del aire en el ambiente y la salud. Como resultado, se obtiene un inventario de emisiones atmosféricas para mejorar la gestión en el manejo de la calidad del aire, y tres software como soporte técnico para las fases de recepción, análisis y control de datos. Se concluye que el procedimiento para gestionar las medidas de control de contaminantes atmosféricos de fuentes móviles y fijas en la Autoridad Territorial Ambiental (ATA) se perfila como una herramienta de gestión orientada a minimizar los riesgos que presenta la contaminación del aire en el ambiente y la salud

Particulate matter emission from paved road surfaces

Imperial Users onl

Local and regional contributions to nitrogen dioxide concentrations in urban areas of the UK

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A methodology for the assessment of air quality in London and Bangkok

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

Investigating the influence of vehicular traffic on a major trunk road on rural air quality

A thesis submittedTraffic population in the UK has grown by 27% in 2002 and predicted to continue to an estimated 38% in 2016 and up to 60% by 2031. This means vehicular emissions from road transport may account for higher proportion of total emissions of pollutants resulting in air pollution with its attendant consequences. Although poor air quality concerns has often been linked to urban areas, many rural areas apparently have locations where air quality objectives may be threatened especially in the wake of increasing vehicular population. Thus, this elicits the necessity to investigate the relationship between vehicular emissions and air quality. This study investigated the influence of vehicular traffic on a major trunk road on rural air quality through continuous measurements of nitrogen dioxide, sulphur dioxide and hydrocarbon between June 2008 and April 2010 along a major trunk road in a catalogued rural environment in the UK. Collection and analysis of pollutants was by Dräger short-term tubes and Dräger passive diffusion tube techniques. Throughout the sampling period, concentrations of sulphur dioxide were not detected using the short-term tube technique but were detected by the passive diffusion tubes. The study found that variations in mean concentrations of the pollutants were synonymous with traffic frequency and were influenced by meteorological conditions especially wind speed, temperature and relative humidity. Results observed concentration decline trend with increasing distance and showed maximum concentrations during winter, mainly in areas of close proximity to anthropogenic source, and minimum in summer. Values between winter year 1 and winter year 2 monitoring campaigns showed significant difference (P Ti (0.346 ppm) > Cr (0.111 ppm) > Cu (0.106 ppm) > Pb (0.026 ppm) > Ni (0.025 ppm). They were found in different magnitudes higher than their respective levels at 50 and 100 m from the trunk road and therefore tend to support traffic origin. Findings from this study show that heavy metals exhibited different degree of correlation between individual elements, ranging from very strong positive to weak, as well as negative correlations. Statistical analyses show that the elements predominantly exhibited statistically significant differences between elements and between distances from the road. Overall, findings from this study demonstrate that both vegetation species prove to be successfully useful in determining the pollution status and trends of traffic-related heavy metals