Using aerial photographic data for inventory of air emissions from road traffic sources: case study in the city of Lisbon

摘要

Road traffic emissions have an overwhelming importance in the air quality of Lisbon city and therefore appropriate spatial allocation of traffic volume and traffic conditions (fleet, mode and driving conditions) is of major importance in air quality studies. However, traffic monitoring data was scarce and limited to some main road lines, and data concerning traffic volumes was associated with sections instead of links as required by air quality models. Origin/destiny studies are expensive and often they would not have enough detail nor are calibrated with real data. Therefore, INVENTAR developed an alternative approach to estimate the traffic air emissions of Lisbon. Aerial photographs were used to estimate moving cars' density for every road link in Lisbon. Travel time surveys using GPS were used to convert moving vehicle density to traffic volumes. Fuel sales and commuting fluxes were used as a top-down approach for calibration. Emissions were estimated for each link using emission factors established according to the EMEP/CORINAIR methodology. Results were used for the official air emission inventory of Lisbon and they will be an important tool for the development of air quality management plans for this region.