Real-Time Groundwater Dynamics Verification in the Embankment’s Substrate during the Transition of a Flood Wave

The scope of the presented research included real-time verification of groundwater dynamics in the zone of the filled erosion channel (crevasses) and in the non-transformed zone of the floodplain area during the transition of a flood wave in the river channel. The technical goal was to provide data for the calibration and verification of mathematical model of groundwater flow. For this purpose, automatic recorders of groundwater level and electrical conductivity were installed in the zones selected earlier with the use of DEM. The measurements were carried out in 3 series during the passage of the flood wave. The obtained results indicate that in the zone of the untransformed terrace, the ascension of the water level between embankments causes the immediate propagation of pressure in the aquifer, while the filtration process itself is considerably limited, whereas the filled crevasse troughs constitute paths of privileged filtration, in particular in the proximal part of the floodplain. The appearance of water with elevated conductivity in the area of the crevasse proves the cyclicality of changes in flow directions, depending on the water level between embankments. The proposed methodology can be a valuable tool in the process of the geotechnical assessment of the construction substrate in the area of flood terraces in the lowland river. The zones with increased water conductivity parameters located near the river channel are also a reasonable place for the construction of coastal water intakes of the Riverbank filtration (RBF) type.