We present a study of the seasonal behaviour of soil moisture in an old embankment levee by means of 2D DC-electrical resistivity tomography monitoring based on an embedded electrode installation. We were able to produce seasonal resistivity change models that are compensated for temperature effects using a seasonal temperature profile model. Time-lapse sections of percentage resistivity changes show spatial and temporal overall consistency with seasonal variations of soil temperature. Discrepancies are likely due to the pavement layer that is not well considered in the inversion process as well as to time-lapse inversion pitfalls. Furthermore, a detailed estimation of seasonal moisture content variations could not be given as an accurate calibration of the employed suction probes was not achievable. Nevertheless, the levee appears to have spatially consistent time variations in soil moisture, clearly influenced by both rainfall and water table and river levels. Future work on developing 3D acquisitions and adding embedded moisture content probes should prove effective to our monitoring design and give a more detailed understanding of the soil moisture seasonal behaviour in the studied stretch of levee.

The building of a solar power station at Thé mis, at 1650 masl on the south-facing slope of the Carlit massif in the eastern Pyrenees, led to an archaeological evaluation from April-June 2009. This evaluation covered a surface of 10 ha that included a medieval village as well as the surrounding agricultural land in terraces. Non-destructive archaeological methods were used for the village. A detailed study of the 6 ha of terraces began with a fieldwalking survey, mapping every visible feature, followed by systematic trial trenches. Fifty-five trenches, 11 in the village and 44 in the fields, were opened. The stratigraphies were then compared with a series of 22 radiocarbon dates and eight relative dates provided by ceramic typologies. This combination of surface and buried evidence supported our preliminary hypothesis about the dynamics of the slope. The results suggest the existence of agrarian features beginning in the Bronze Age and reveal that the field patterns were frequently transformed, both in the Medieval and Early Modern periods. The transformations in the terrace fields after the village was abandoned are as interesting as those during occupation because, contrary to the idea of a fixed, unchanging landscape after the end of the Middle Ages, they challenge the idea that mountain zones are marginal spaces by nature, or were marginalized later.

Although DC electrical resistivity imaging is widely applied to dike investigation, either rapid 2D or high‐resolution 3D approaches fail to address actual needs. An intermediate electrical resistivity imaging approach referred to as “3D‐“ is introduced in this paper. The methodology is based on existing tools, and it offers useful and sufficiently reliable 3D images of the investigated structure within a cost‐effective and flexible procedure. The survey design, the model discretisation, and the thorough integration of a priori information are the main phases of this procedure. To demonstrate the benefits and limitations of this approach, it is applied to an existing stretch of embankment levee along the Loire River. A numerical study was carried out both on synthetic and real data to assess the 3D imaging capability of the approach and the influence of prior information on the inversion outputs. The important role of a priori information is shown to be even more essential here. The results demonstrate the efficiency and versatility of the 3D‐ approach for reliable and cost‐effective investigations of long dikes.