Air Quality Modelling in Latvia

As a potential member country to the European Union (EU), Latvia has harmonized the national environmental legislation with the EU air quality (AQ) legislation. The AQ management system in the country is being developed in accordance with the requirements laid down in the appropriate EU directives thus introducing advanced management tools based on the AQ modelling. According to the Latvian legislation, the simple empirical model, “Ecolog” (Russia), should not be used for air quality modelling. The new tool for pollution dispersion assessment and management, EnviMan, OPSIS AB Company, Sweden was obtained by the Latvian Hydrometeorological Agency in 1998. Initially it was used only for processing and storage of data collected from automated AQ monitoring stations. First modelling exercises began in 20002001 when a map of Riga was digitized and related to the GIS databases with regard to emission sources; input meteorological data were prepared as well. At the moment, the digital maps have been prepared, and source emission databases are being revised for another 9 industrially developed Latvian towns.