Hydrogeological Analysis Supported by Remote Sensing Methods as A Tool for Assessing the Safety of Embankments (Case Study from Vistula River Valley, Poland)

Abstract

We aim to answer a question: how does the evolution of fluvial environment affect to risk of embankments failure in lowland rivers and how can we identify and describe places at risk of levees failure using the remote sensing data? The study was carried out in the Vistula River valley near Magnuszew (middle Vistula course, central Poland). 24 geological boreholes were drilled to a depth of 2.0–8.5 m and groundwater table observations were conducted in a monitoring network consisting of 22 wells, 5 piezometers (screened within the Holocene alluvial aquifer) and 2 temporary water gauges. Identification of the diversity of the geological structure of the floodplain was supported by airborne laser scanning imaging, as well as high resolution satellite images and aerial photos. This remote sensing study allowed the creation of a conceptual model of hydrogeological conditions. Study takes into account the effects of the land forming activity of flood waters resulting from the evolution of the fluvial environment in the Holocene. Created conceptual model subsequently fed into the construction and calibration of a mathematical groundwater flow model using MODFLOW software. The study allowed the identification and characterisation of intensified groundwater flow zones. Concentrated flow in the substrate of flood protection levees constitutes a threat to their stability. Documented in many publications climate change will induce in future climate scenarios an increase in rainfall and prolongation of dry periods. The implementation of the methodology of identifying the geological forms with the use of presented techniques allows the identification of sections of flood embankments potentially at risk of failure.