Mapping and prediction of geogenic radon potential in Germany is based on the results of standardized field measurements, taking into account gas radon activity concentration, gas permeability and the geological situation as the major parameters for its classification and regionalisation. In a first approach, areas with metamorphic and silica-rich volcanic rocks as well as with distinct Paleozoic sedimentary rocks, characterized by enhanced radionuclide contents, were surveyed in regional scale. The sampling grid for these investigation areas was 535 km or denser, depending on the specific geological situation. For the major part of the total area of Germany which is covered by younger Mesozoic to Cenozoic rock units, the expected geogenic radon potential is
medium-to-low. The sampling grid within these larger lithologically homogeneous areas was therefore more widely spaced. The regionalisation of the measured radon values was calculated on the basis of rasterized geological maps, taking into account the lithological boundaries as
delimiting borders for the data interpolation. Such a GIS supported approach will allow further regional discrimination by including digital terrain models and soil
maps. The obtained radon potential maps serve as a planning aid for government administration to direct further investigations and preventive measures. Finally, different techniques for regionalisation according to administrative boundaries are discussed
