Résumé
The Foussoubie karst, located on the right bank of the Ardèche Gorges (France), is the second longest network in the Bas Vivarais (23 km of recognized galleries). The Foussoubie system is fed by a main sinkhole: “la Goule” towards an outlet: “l’évent de Foussoubie”. The Foussoubie system, influenced by a Mediterranean climate, is known for its violent and dangerous floods having caused several casualties. The network is mainly shallow (average depth from “la Goule”: 82 m) and partially submerged. Sensors distributed along the network acquired measurements of temperature and water level between 2010 and 2018. These measurements, combined with the good speleological knowledge of the conduits, allowed carrying out statistical and systemic analysis. Correlations, as well as sorted discharges have been calculated on different floods to improve knowledge of the network’s hydraulic characteristics. The system appeared as very reactive and transmissive. It was shown that the reactivity of this dominant conduit-type system is linked to the soil and karst saturation. In addition, a “threshold” swallowed flow, constrained by the conduit section, was approached at the sinkhole “la Goule”.