Air Quality Modelling in Latvia

As a potential member country to the European Union (EU), Latvia has harmonized the nationalenvironmental legislation with the EU air quality (AQ) legislation. The AQ management system in thecountry is being developed in accordance with the requirements laid down in the appropriate EU directivesthus introducing advanced management tools based on the AQ modelling. According to the Latvianlegislation, the simple empirical model, “Ecolog” (Russia), should not be used for air quality modelling. Thenew tool for pollution dispersion assessment and management, EnviMan, OPSIS AB Company, Sweden wasobtained by the Latvian Hydrometeorological Agency in 1998. Initially it was used only for processing andstorage of data collected from automated AQ monitoring stations. First modelling exercises began in 2000-2001 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, andsource emission databases are being revised for another 9 industrially developed Latvian towns.