Hydro-geophysical Investigation via 2D Seismic Reflection, Nefzaoua CI and CT Aquifers, Southwest Tunisia

Groundwater resources in the Nefzaoua region are represented by two large covered aquifer systems: Continental Intercalaire (CI) and Complexe Terminal (CT). Waters housed in these two aquifers are potential targets for drinking, manufacturing, and especially for irrigation. Sampling rates increase daily, resulting in a significant drop of piezometric levels. Continuation of the current exploitation regime will lead to irreversible effects on quantity and quality of water in the two aquifers. This work integrates geology, hydrogeology and geophysics data for understanding the CI and CT aquifer systems. Petroleum wells, water boreholes, and seismic profiles led to precise distribution of sedimentary series, geometric characterization of reservoir layers, and delimitation of the CI and CT aquifer intervals in the Nefzaoua area.2D seismic reflection analysis highlights subsurface sedimentary evolution in relation with tectonic deformations that have affected the southern Tunisia during the Mesozoic and Cenozoic times. The proposed geo-seismic section accurately highlights structure and geometry the CI and CT aquifers. The inferred model reveals relationships and communications between the reservoir layers, and explains its variations. The obtained results led to refine and complete the previous geological and hydrogeological results, and highlight new favorable zones for exploitation of the CI and CT aquifers.