Contamination in the Danube Basin goes online
Contamination in the Danube Basin goes online
A novel web-based geochemical and contamination map series for the Danube Basin supports contamination risk assessment and helps spread environmental communication.
A screen shot from the ICPDR web page for cadmium (Cd) distribution in stream sediments in Hungary according to the Geochemical Atlas of Hungary, produced by the Geological Institute of Hungary (MAFI), based on a high-density 50x50km sampling grid. Coloured areas show catchments sampled for stream sediment at the outlet location.
Is the region in which I live contaminated? Is contamination higher where our children play and families live? To answer these questions you need a European-wide geochemical map showing the distribution of toxic elements such as arsenic, lead, zinc or cadmium. Such maps require advanced scientific knowledge and the broadest international cooperation. This is now available for the Danube Basin through the ICPDR from the Geochemical Expert Group (Association of European Geological Surveys; EuroGeoSurvey). With one click on the web page, you can wander around Danube landscapes and find pristine lands or areas of possible contamination!
The web application, developed by the Geochemistry Programme at the Geological Institute of Hungary (MAFI), shows the distribution of toxic elements in the Danube Basin at various scales along with topographic information such as country borders, roads, settlements, water courses and catchment boundaries. Users can choose a toxic element to be displayed or can overlay contaminated areas in a GoogleEarth environment and fly over the terrain in 3D. Plenty of explanation, user guidance and links are provided for the interest of the public and for use by experts and decision makers.
The topographic maps are based on internationally recognised databases such as the EU Catchment Characterisation and Modelling drainage and catchment database. Geochemical maps in the web page feature the Water Framework Directive priority substances: cadmium, mercury, nickel and lead. In addition, geochemical maps are available for the other ICPDR Danube Basin List of Priority Substances arsenic, chromium, copper and zinc.
Using the European Atlas. Geochemical data for the website comes from the EuroGeoSurveys Geochemical Expert Group ‘Geochemical Atlas of Europe’, which is currently the largest and highest quality toxic element multi-media and multi-element spatial database available in Europe. This database, a part of the International Union of Geological Sciences Global Geochemical Mapping Programme, is based on a low-density 160x160km global grid where stream water, stream sediment, topsoil, subsoil and floodplain sediment samples were collected and analysed for the whole periodic table, in addition to stream water nitrite, pH and other environmental parameters.
The advantage of using the publicly available European Atlas is that it is fully harmonised for sampling, laboratory analysis and quality control, and data processing methods are the same for all the participating Danube Basin countries. However, its low sampling density is a disadvantage (1 sample per 5000 square km) and a significant part of the Danube Basin is not covered.
National information. The other source for geochemical maps on the website is high-density, single-media, multi-element National Geochemical Maps. The National Maps have a higher sampling density (1 sample per 500 square km, on average, however these maps cannot be compared across country borders because of the differences of sampling media and various sampling and laboratory analysis methods used. Furthermore, not all Danube countries, have national geochemical maps. The National Geochemical Maps publication policy varies among the countries therefore the interested user should contact the relevant national geological survey for the original maps and data (click on ‘national contact’ on the web page).
Looking ahead to further development. The next step for this project would be to create the uniform Geochemical Atlas of the Danube Basin. As the current website demonstrates, the harmonised European geochemical atlas available now only covers a part of the basin, and its sampling density is too low to support planning and management activities at the catchment scale. High resolution national geochemical maps cannot be compared because of the various methods used, which is particularly problematic when studying transboundary effects along the borders of the 11 Danube countries. It is therefore necessary to make a harmonised high-density, multimedia, multi-element geochemical atlas for the entire Danube Basin using the EuroGeoSurveys methods, experience and capacities.
An important future development would be to integrate all geochemical maps into GoogleEarth (currently available only for a few countries). In order to enable contamination risk assessment, it will be important to include other data layers in the database, such as contamination sources like mine sites or sensitive receptors such as protected ecosystems, agricultural areas on floodplains or urban areas.
For more information about the geochemical and contamination maps for the Danube Basin, please visit: www.icpdr.org/geochemical_maps/
