Groundwater Recharge and Resources in the Tundzha River Basin, Southeast Bulgaria

This article presents the assessment results of the long-term annual average groundwater recharge for the territory of the Tundzha River catchment area. In order to assess those results, a GIS-method has been applied based on spatial analysis of the slope of the relief, soil cover and aquifer properties. A series of maps is presented and a quantitative analysis of the results obtained is carried out. The mean annual groundwater recharge ranges from 4 to 483 mm, or about 55 mm on average for the catchment area. Additional calculations have been made for water management purposes. For individual groundwater bodies that fall into the catchment area of the Tundzha River (managed primarily by the East Aegean River Basin Directorate) both groundwater recharge and their natural groundwater resources were assessed (based on the outcrop areas of the respective bodies).