The database for the map is provided by approx. 14,950 bore holes with a depth of 40 m or more in the borehole database of the Working Group Geological Survey of the Senate Department for the Environment, Transport and Climate Protection, 1,900 interpretation profiles from geological cuts, data on rock specific conductivity and heat capacity, as well as the depth to groundwater of the main aquifer derived on the basis of the groundwater level measurement of May 2017 and the digital terrain altitude data.
