Résumé
Groundwater flow in karst aquifers is influenced by the presence of self-organized networks of large conduits. Existing methods which use artificial tracers or tethered robots, provide a limited amount of information on the network's geometry, and on the flow regime that occurs in the conduits. To address hydrogeological problems relative to karst aquifers, the characterization of the flow conditions in the network of conduits is needed. However this is a challenging task. We present a novel wireless probe which is developed to allow remote characterization of main flow directions and regime in subsurface environments. The relatively small (40 mm diameter) spherical autonomous probe is designed to allow transport by the water stream. During its journey in the flow, the non-expensive electronic equipment installed on board measures and records orientation data. Once the probe is retrieved, the recorded measurements can be analyzed. The encouraging preliminary laboratory results indicate that the new probe can accurately characterize different flow directions and regimes. This new autonomous probe offers a chance to help address the challenging task of characterizing flow in unknown drowned karst conduits.