Tesis doctoral de María GonÁ§alves Ageitos
The urban air pollution affects human health, causes damage to ecosystems and transboundary air pollution. The southern mediterranean region and specifically the iberian peninsula are commonly affected by highly polluted episodes. The high o3 levels, and specifically the no2 and pm concentrations in urban areas, are of special concern, frequently exceeding the european air quality targets. On road traffic is the main source of anthropogenic emissions in the urban environment. Different strategies addressed to reduce this contribution are being currently implemented and tested. The quantitative assessment of their effects in advance is fundamental to help decision makers. Air quality modelling is the most suitable tool to perform this kind of evaluations. this phd thesis proposes the use of the mesoscalar wrf-arw/hermes/cmaq modelling system with high resolution to test in advance such strategies for on-road traffic emissions abatement. It focuses on the two most populated urban areas of spain, barcelona and Madrid, which constitute a typically coastal and continental environment. The 17-18 june, 2004 is chosen as the study case. It fits in a poor air quality situation in both areas but also in an usual traffic circulation pattern (working days). Several feasible short-term strategies are selected and implemented in the emission model in the most realistic way as possible. They include: use of alternative fuels, such as natural gas or biodiesel, introduction of new technologies, such as hybrid electric vehicles, and urban management schemes, such as speed circulation limit. They are evaluated in terms of emissions, fuel consumption and air quality changes in the urban areas and at a regional scale, over the north-eastern and central iberian peninsula. the effects of these strategies depend on the study areas. The factors that condition these differences are mainly: (1) the specific vehicle fleet composition, having barcelona a larger proportion of diesel and commercial vehicles and lower quantity of passenger cars than Madrid; (2) the different contributions of the activity sectors to anthropogenic emissions, which in barcelona and the north-eastern iberian peninsula reflect a heavier industrial activity against Madrid and the central iberian peninsula region; (3) the different contributions of atmospheric processes leading to the concentration of pollutants; their quantification leads to the observance of characteristic transport patterns of a coastal area and very complex terrains in barcelona, and a much simpler behaviour in Madrid, a typically continental area; (4) the chemical sensitivity regime also differs, which particularly affects the o3 response to nox abatement strategies. the effect of all the tested strategies in urban no2, so2 and pm10 concentrations is positive, being lower than in the base case. Nevertheless the extent of this effect largely depends on the affected fleets and on the urban area of application. The introduction of natural gas vehicles proved to be specifically effective in reducing so2 and pm10 concentrations in barcelona and Madrid areas. The introduction of biodiesel as a fuel would slightly affect the urban air quality levels, improving mainly the so2 levels. The use of hybrid cars affects the nox emissions considerably, reducing no2 urban levels. Moreover in Madrid it causes a noticeable reduction in the local o3 concentrations. The barcelona photochemical regime involves local o3 concentrations increase when reducing nox emissions. the introduction of an 80 km h-1 speed limit in the barcelona area reduces no2 and pm10 levels, specifically in the zones affected by the measure. The inclusion in the model of hourly speed data from measurement campaigns instead of the previously constant speed considered, allowed assessing the gains of such a measure in a more realistic manner, taking into account real circulation patterns and the congestion effect. the effects of the selected strategies are always positive in downwind areas, even in terms of o3 concentration. the application of high resolution modelling proved to be a useful tool to quantitatively asses the effect of management strategies. The detailed emissions inventories and the availability of emission factors for new technology vehicles or alternative fuels are key factors to this kind of developments.
Datos académicos de la tesis doctoral «Assesing variations in urban air quality when introducing on-road traffic management strategies by means of high-resolution modelling. application to barcelona and Madrid urban areas«
- Título de la tesis: Assesing variations in urban air quality when introducing on-road traffic management strategies by means of high-resolution modelling. application to barcelona and Madrid urban areas
- Autor: María GonÁ§alves Ageitos
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 09/03/2009
Dirección y tribunal
- Director de la tesis
- José María Baldasano Recio
- Tribunal
- Presidente del tribunal: Carlos Borrego
- lucio Alonso alonso (vocal)
- Fernando Martín llorente (vocal)
- oriol Jorba casella (vocal)