Adding virtual measuring stations to a network for urban air pollution mapping

Anne-Lise Beaulant (1) , Gilles Perron (2) , Joseph Kleinpeter (2) , Christiane Weber (3) , Thierry Ranchin (1) , Lucien Wald (4)

1 CEP - Centre Énergétique et Procédés
2 ASPA - Association pour la Surveillance et l'Etude de la Pollution Atmosphérique en Alsace
3 IV - Image et ville
4 CEP/Sophia

Maps of pollutants concentration are usually generated by means of interpolation and extrapolation methods. The quality of the results depends mainly of the number of permanent or temporary measuring stations. This paper deals with a method for the virtual densification of the network of stations. The method creates “virtual measuring stations”. It aims at improving the quality of interpolation by increasing the number of data on pollutant concentration. The virtual stations are determined by the means of a classification method applied to each pixel of the area under concern. Discriminating elements are pollutants emission classes, land cover types, urban morphological indicators created to this purpose and distance to major roads. A first implementation was made for particulate matter (PM) for the city of Strasbourg (France) using thin-plates spline interpolation method in Arcview 9 GIS. The relative Root Mean Square Error decreases from 49% for five input stations down to 15% for the virtual stations.

Mots clés: Pollution map; Virtual station; Morphological indicators; Thin plates spline; Interpolation method; Particulate matter (PM)

Domaines: Sciences de l'ingénieur [physics]; Traitement du signal et de l'image [eess.SP]; Sciences de l'environnement; Sciences de l'Homme et Société; Géographie; Informatique [cs]; Traitement du signal et de l'image [eess.SP]

Anne-Lise Beaulant, Gilles Perron, Joseph Kleinpeter, Christiane Weber, Thierry Ranchin, et al.. Adding virtual measuring stations to a network for urban air pollution mapping. Environment International, 2008, 34 (5), pp.599-605. ⟨10.1016/j.envint.2007.12.004⟩. ⟨hal-00464795⟩