15 QUAL I TÉ GÉOPHYSIQUEAPPLIQUÉE © EDP Sciences, 2026 DOI: https://doi.org/10.1051/978-2-7598-3934-6.c904 Introduction T. Gaillard and J.-L. Mari Geophysical and hydrogeological investigations play a pivotal role in aquifer characterization. Here, we focus on a carbonate limestone aquifer in the Poitou region (France). We show how hydrogeology and geophysics have contributed to revising regional groundwater flow models and have provided significant new insights. The study highlights how a multidisciplinary geoscientific approach, integrating geophysical, hydrogeological, and stratigraphic analyses, can refine and strengthen a groundwater flow model. The study area is located at a geological transition zone between the Aquitaine and Paris basins in France, known as the Poitou threshold. Chapter 1 of the book provides a geological overview of the threshold. Chapter 2 contains a detailed synthesis of the middle Jurassic limestone stratigraphy, which forms the basis for defining the regional geodynamic context. Particular attention is given to the Poitiers region, including newly developed geological cross-sections that delineate key stratigraphic features in the central part of the threshold. From a hydrogeological perspective, the Poitou threshold exhibits notable karst flows, despite its low hydraulic gradient, the relatively limited limestone thickness compared to the Périgord and Causses regions of the Aquitaine basin, and an altitude that does not exceed 150 m above sea level. Geologists of the 19th and 20th centuries unanimously attributed the origin of these karst systems to fissures formed under tectonic stress. The concepts underpinning the hydrogeology and karst morphology of the Poitou threshold are explored in detail in Chapter 3 entitled “Hydrogeology of the Poitou Threshold.” The traditional understanding has been challenged by recent research conducted on a hydrogeological platform established near Poitiers under the leadership of
RkJQdWJsaXNoZXIy NjA3NzQ=