FIG. 3. Measurements performed in the DjR infiltration basin. Ground penetrating radar GPR) reflections calibration was performed from the trench wall excavated on Grid A and Grid B (results are presented by Goutaland et al., 2005). This calibration was used to interpret GPR profiles from Grid C in terms of stratigraphy and hydrostratigraphy. This interpretation was compared with volumetric water content variations at –0.50 and –1.15 m under the basin surface.