Auswirkung einer künstlichen Hochwasserwelle auf den fließgewässernahen Grundwasserleiter

The processes in the hyporheic zone due to varying hydraulic boundary conditions, e.?g. flood waves in surface water are frequently characterized as transient. However, their effects are often difficult to assess. Therefore, the effects of a single artificial flood wave on the interaction between groundwater and surface water in the hyporheic zone was examined by measuring the responses of hydraulic head, temperature and chemical constituents in a stream and its floodplain. Before this hour event the groundwater temperatures were recorded over a period of several weeks using temperature loggers. The analyses of the field experiment show a significant positive correlation of artificial flood wave and hydraulic heads in the groundwater. The water level exhibits an immediate reaction on the passing flood wave. The transport of water from stream to groundwater which was tested by a tracer and measurements of indicator parameters has not been proven clearly. Also, measurements of temperature in the groundwater during the flood wave could not reveal an influence of cold water from the stream on the groundwater. The results show, however, that even short term and local changes in hydraulic conditions impose an effect on groundwater.