Resistivity imaging of river embankments: 3D effects due to varying water levels in tidal rivers

Electrical resistivity tomography (ERT) has seen increased use in the monitoring condition of river embankments, due to its spatial subsurface coverage, sensitivity changes internal states, such as moisture content, and ability identify seepage other erosional process with time-lapse ERT. Two-dimensional ERT surveys are commonly used time site constraints, but they often sensitive features anomalous proximal survey line, which can distort resultant inversion a three-dimensional (3D) effect. In tidal embankment, these 3D effects may result from changing water levels salinities. data at Hadleigh Marsh, UK, showed potential evidence local bodies. Synthetic modelling was quantify on embankments. The shows that effect environment occurs (for geometries studied) when undertaken high distances less than 4.5 m electrode array 1 spacing. is enhanced brackish waters, common environments, larger Different geologies, compositions, proximities model parameters expected induce varied terms magnitude, should be considered surveying minimize artefacts data. This research highlights importance appropriate geoelectrical measurement design for embankment characterization, particularly saline