3. Hydrography of Hungary

The potentials and hazards of surface and subsurface waters are very important elements of the Hungarian environment. The geographical location of the region (e.g. basin-like character, continental water household) determines the possibilities (e.g. great subsurface water bodies) and the hazards (e.g. extreme water regime of the rivers, flood hazard). In the first part of the chapter, the geographical background of the surface waters is introduced, describing the most important morphological, hydrological and ecological characteristics of rivers and lakes. Besides the description of the genetic lake types, a detailed analysis is given on the Lake Balaton, Lake Fertő and Lake Velence. Besides their evolutionary history, the temporal changes of their water households during the last decades are also explained, especially the responses of the lakes on climate change are emphasized. Considering the environmental problems of the subsurface waters, those of the artesian waters (e.g. recharge, water household) are discussed in detail, as in Hungary, these problems are the most important from the point of view of thermal water and drinking water utilization. The drinking water demand is fulfilled by bank-filtered wells and karst waters; thus, they are highlighted. Besides, a general picture is drawn on the human impact on waters and the way of their management in Hungary.