Regional hydrogeology of the Tokaj Mountains world heritage site, North-East Hungary

Tokaj Mountains, as a large Miocene volcanic region in North-East Hungary, is the homeland of the famous Tokaj wine. The Tokaj wine region can be found on the world heritage list of UNESCO. Although there were several mineral prospecting activities at the Tokaj Mountains in the 1960s and 1970s, the groundwater resources on a regional scale have not been revealed yet. The regional water budget and the groundwater flow systems were not known before the complex hydrogeological investigations recently carried out by the University of Miskolc. Although shallow groundwater is being produced at some small-scale waterworks to cover local drinking water demands, it has believed that there is no chance to find thermal water and to extract underground heat in this volcanic area because of the average hydraulic conductivity of the subsurface formations is very low. It is encouraging that intensive tectonic lines were determined by geophysical methods during the recent field campaigns. The presence of valuable thermal water resources was discovered along these tectonic lines opening new perspectives in geothermal exploration in this region. After the extensive field measurements, a regional scale groundwater-flow model was constructed to characterize the subsurface flow systems and the available shallow and deep groundwater resources of the Tokaj Mountains. A special prospecting methodology involving geological, hydrogeological and surface geophysical methods was elaborated to find thermal water resources in this complex geological/ecological environment.