Groundwater–Surface
Water Interaction: Process Understanding, Conceptualization and Modelling (Proceedings of Symposium HS1002 at
IUGG2007, Perugia, July 2007). IAHS Publ. 321, 2008, 30-38.
Surface water–groundwater interactions: hydrological
and biogeochemical processes at the lowland River Spree (Germany)
Jšrg LEWANDOWSKI & Gunnar N†TZMANN
Leibniz-Institute of Freshwater Ecology and Inland Fisheries,
MŸggelseedamm 310, D-12587 Berlin, Germany
lewe@igb-berlin.de
Abstract Hydrological exchange processes between surface water and groundwater are studied on a test-site at the lowland River Spree. Normally, a hydraulic gradient in the aquifer causes groundwater flow into the stream. However, water level fluctuations of the stream spread out surprisingly quickly into the near-surface aquifer of the flood plain. As a result, an inverse hydraulic gradient and exfiltration of surface water into the aquifer and temporary bank storage, take place. Additionally, measurements of chemical compounds are conducted to investigate the capacity of the flood plain to buffer pollutant inputs. While nitrate is completely removed, phosphate concentrations increase in the anaerobic groundwater. The temporal variability in nutrient concentrations is low while spatial variability is higher than previously expected.