The thermal waters in Sofia City (Bulgaria): importance, condition and problems

Sofia, the capital of Bulgaria, is situated in a region rich thermal waters, which were major factor for establishment and development city. The spring city center Sofia has been use since ancient times. As expanded rapidly 19th 20th centuries, it absorbed many other sources water. In addition, available volume usable water increased with construction abstraction wells. prevailing types waters are sourced from Mesozoic rocks at base graben. temperatures range between 21 °C 54 °C, mineralization up to approximately 1 g/L total dissolved solids (TDS). There only one source deeper rock formations 4 TDS. population utilizes resources various degree, mainly bottling natural mineral Some used balneology, sport, recreation sanitation; however, their potential not sufficiently utilized. Considering importance its population, numerical model was set study impact subway on Sofia.