Subsurface imaging of fluvial deposits of the Vistula River valley in Krak?w (southern Poland) by 2D ERT survey

We describe the application of 2D ERT (electrical resistivity tomography) surveys to investigate the spatial complexity of fluvial de pos its of the Vistula River val ley in the east ern part of Krakow (south ern Po land). All ERT sur vey lines were com pleted within the in dus tri ally in flu enced floodplain of the Vistula River at two re search sites. Due to the trans for ma tion of the nat u ral state of the en vi ron ment through many years of in dus trial ac tiv ity of the ArcelorMittal Krakow plant, some of the geomorphological elements analysed have been irretrievably transformed and hidden by anthropogenic accumulations such as waste land fills and en gi neer ing struc tures. Hence, many years of soil con tam i na tion have changed the pri mary re sis tiv ity char ac ter is tics of the subsurface. For this pur pose, the mea sure ment ar ray ap plied com bines stan dard ar rays, i.e., Wenner-Schlumberger and Di pole-Di pole, which gave im proved re sults (higher res o lu tion) in com par i son to the stan dard single array. The data interpretation method was supported by the calculation and visualization of the vertical and horizontal gradients of the interpreted resistivity within the resistivity sections. This approach allowed accurate determination of resistiv ity bound aries on the ERT resistivity sections and thus helped lithological in ter pre ta tion of the flu vial de pos its in the re search area. The re sis tiv ity of wa ter in a chan nel lo cated within one of the ana lysed ar eas has im pacted some of the re search re sults. Fur ther more, 2D ERT for ward mod el ing was im ple mented to gen er ate syn thetic datasets. The syn thetic data al lowed investigation of the influence of groundwater contamination on the resistivity distribution within superficial layers, and also tested the abil ity of the 2D ERT model to rec og nize the de tailed spa tial dis tri bu tion of palaeomeander (me an der scar) infills. All meth ods have pro vided new in for ma tion on the in dus tri ally in flu enced floodplain of the Vistula River in Krakow.

Automated summary

This study applies 2D electrical resistivity tomography (ERT) surveys to investigate the spatial complexity of fluvial deposits in the Vistula River valley in Krakow. Due to industrial activities, many geomorphological elements have been transformed and hidden. The methods used in this study provide new information on the industrial influence in the study area, allowing accurate lithological interpretation.