Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2017-477 Manuscript under review for journal Hydrol. Earth Syst. Sci. Discussion started: 28 August 2017 c Author(s) 2017. CC BY 4.0 License. Imaging groundwater infiltration dynamics in karst vadose zone with long-term ERT monitoring Arnaud Watlet1,2, Olivier Kaufmann1, Antoine Triantafyllou1,3, Amaël Poulain4, Jonathan E. Chambers5, Philip I. Meldrum5, Paul B. Wilkinson5, Vincent Hallet4, Yves Quinif1, Michel 2 2 5 Van Ruymbeke , Michel Van Camp 1Geology and Applied Geology Unit, Faculty of Engineering, University of Mons, Place du Parc 20, 7000 Mons, Belgium. 2Seismology-Gravimetry, Royal Observatory of Belgium, Avenue Circulaire 3, 1180 Uccle, Belgium. 3Laboratoire de Planétologie et Géodynamique — Nantes (LPGN), UFR Sciences et Techniques, Université de 10 Nantes, UMR-CNRS 6112, Rue de la Houssinière 2, BP92208, 44322 Nantes Cedex 3, France 4Department of Geology, University of Namur, Rue de Bruxelles 61, 5000 Namur Belgium 5Geophysical Tomography Team, British Geological Survey, Nottingham NG12 5GG, UK Correspondence to: Arnaud Watlet (
[email protected]) Abstract. Water infiltration and recharge processes in karst systems are complex and difficult to measure with 15 conventional hydrological methods. Especially, temporarily saturated groundwater reservoirs hosted in the vadose zone can play a buffering role in water infiltration. This results from the pronounced porosity and permeability contrasts created by local karstification processes of carbonated rocks. Analyses of time-lapse 2-D geoelectrical imaging over a period of three years at the Rochefort Cave Laboratory (RCL) site in South Belgium highlight variable hydrodynamics in a karst vadose zone. These data were compared to conventional 20 hydrological measurements (drip discharge monitoring, soil moisture and water conductivity data sets) and a detailed structural analysis of the local geological structures providing a thorough understanding of the groundwater infiltration.