Untersuchungen der Bodenwasserbewegung mit stabilen Isotopen in Hinblick auf die Grundwasserneubildung

摘要

The knowledge of the processes of groundwater recharge is crucial for protection of our groundwater resources. Therefore investigations on the water balance and stable isotopes (oxygen-18 and deuterium) were carried out for the Scots pine forest {Pinus syl-vestris L.) at the forest meteorological experimental site Hartheim (southern upper Rhine plain in southwest Germany) in order to analyse flow processes in the unsaturated zone and processes of recharge. Due to water balance calculations (from 08/2003 to 07/2004) an excess of water in the upper soil layer of 291 mm was calculated, which is available for the infiltration into deeper layers. The observed damping and temporal delay of the isotope signal with increasing soil depth could be quantified by a sine curve fit, and mean flow velocities of 0.5 cm/d for the upper soil layer were estimated.