The present map of groundwater temperature distribution is based on current measurements at 124 groundwater measurement points in the State of Berlin. These temperature measurements were carried out in 2010, and complemented with temperature data from the Senate Department’s data base.
In addition, temperature measurements have been carried out regularly every 2 months February 2008 at specially established unfiltered groundwater measurement points, which have the special feature that they can be filled with water almost to ground level, which permits monitoring of the annual temperature progression even in subsoil not saturated by groundwater.
As a rule, the temperature profiles of the groundwater level up to the measurement depth are ascertained with a measurement point interval of 1 m. The measurement error which arises from calibration inaccuracy and measurement inaccuracy of the device, as well as measurement inaccuracy of the object of measurement (e.g., due to heat convection at the measurement points) can be assumed at at least ±0.3°C.
Update on the Data as of 2010
The temperature measurements carried out over the past 30 years at 124 selected measurement points indicate changes Towards a warming of the groundwater, starting near the surface and increasingly extending into the deeper subsoil to a depth of 20 m.