189 Conclusion Full waveform acoustic logs provide mechanical parameters (e.g., P-wave velocity) and are used in seismic inversion to define karst detection indices. Vertical Seismic Profiling (VSP) supports time-to-depth conversion and can indicate karst features through Stoneley wave analysis; • 3D imaging of the aquifer reservoir. In karstified limestone aquifers, seismic methods are recommended to identify major karstic levels. The processed 3D seismic volume is converted into depth, then into a pseudo-velocity model constrained by acoustic logs, and finally into a pseudo-porosity model after calibration with borehole data; • hydraulic tests. Cross-hole pumping tests are used to detect flow paths. High hydraulic diffusivity observed in slug tests aids in building connectivity maps. At the HES site, such tests differentiate wells that are hydraulically connected to the karst network from those that are not; • tracer tests. Tracer breakthrough curves help define the number and nature of distinct flow paths between injection and observation points. These dye tracer tests also highlight the role of boreholes in the mixing of karstic levels by identifying ascending or descending hydraulic gradients within each borehole; • combined geophysical and hydrogeological analysis. The integration of these data sets enables the detection of water-producing zones and the delineation of probable karst conduit networks. Beyond the detailed case study of the Dogger limestone at the Poitou threshold, the authors offer a robust methodology for seismic and stratigraphic characterization that can be applied to other hydrogeological contexts and reservoir studies.
RkJQdWJsaXNoZXIy NjA3NzQ=