Application of GPR method for identifying riverbed erosion zones on the example of selected section of the vistula valley in Warsaw

<p>In the article the occurrence of several natural thresholds in Vistula River valley was discussed. These forms are stabilizing river channel regime and impeding shipping at the same time. The example of application of ground penetrating radar (GPR) for detecting and identifying the erosion zones in the bottom of the river valley was presented. The investigations were carried out along the chosen section of Vistula River in the vicinity of Gdansk Bridge (Most Gdanski) in Warsaw. The survey was conductedfrom a motor- boat with the MALA Ground Explorer (GX) georadar system installed with 160 MHz screen antenna. The prospection down to 7.5 m below the water surface was obtained. The applied methodology allowed to obtain radar echograms indicating the following anomalies: from the river bottom, from cohesive soil (including Neogene clays) and from thresholds (noticeably elevated forms in the bottom). In identifying and interpreting georadar anomalies, archival boreholes data were used.</p>