Earth Embankments constructed from compacted material are an integral part of any flood defence network. In the UK alone more than 34,000km of embankments protect housing and infrastructure from estuarine and coastal flooding. Many such embankments are in a poor state of repair and with rising sea levels and increased levels of precipitation predicted results of climate change, such flood defences will be tested with increasing regularity. Fissures forming due to desiccation in clayey soils have been shown as a potential source of embankment failure during overtopping. Current methods of visually identifying fissures in flood embankments are inadequate particularly when faced with dense vegetation. The extent of Assuring cannot be discovered without the use of trenching, which is costly and destructive to the embankment structure. Electrical Resistivity Tomography (ERT) offers a non-invasive method for appraising the embankment structure. ERT has been shown to be sensitive to the presence of fissures in laboratory studies and an effective method for monitoring the onset of fissuring with inversion models mapping the fissure positions and allowing their growth to be observed. The presented study compares the use of a survey using ERT on the Thorngumbald embankment, near Kingston Upon Hull, UK, with previous laboratory studies on scale models using miniature resistivity arrays. Large scale scans across the slopes of the embankment showed areas of confirmed fissuring, while miniature arrays were used to fully map the fissures in the subsurface. The positions of surface fissures matched with those resolved from the resistivity data and the results compare favorably with those achieved in the laboratory. Additionally scans were taken across the embankment revealing serious fissuring on the landward face, the side most affected by heavy vegetation.
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