Feasibility and limits of Electrical Resistivity Tomography to monitor water infiltration through karst mediumduring a rainy event
Faisabilité et limites de la tomographie de résistivité électrique pour surveiller l'infiltration d'eau dans les zone karstique pendant un événement pluvieux
Carrière, S.D. ; Chalikakis, K. ; Danquigny, C. ; Clément, R. ; Emblanch, C.
Type de document
Chapitre d'ouvrage scientifique
Affiliation de l'auteur
INRA UMR 1114 EMMAH AVIGNON FRA ; INRA UMR 1114 EMMAH AVIGNON FRA ; INRA UMR 1114 EMMAH AVIGNON FRA ; IRSTEA ANTONY UR HBAN FRA ; INRA UMR 1114 EMMAH AVIGNON FRA
Résumé / Abstract
The common hydrogeological concepts assume that water enters in karst media by preferential pathways. But it is difficult to identify these pathways, particularly if soil or scree covers the karst features. When and where does water enter in the hydrosystem? How fast? A unique large scale Electrical Resistivity Tomography (ERT) surface based time-lapse experiment was carried out during a typical Mediterranean autumn rainy episode (230mm of rain over 17 days). 120 ERT time-lapse sections were measured over the same profile during and after this event (30 days). The main goal was to evaluate efficiency and limits of the ERT to monitor water infiltration, under natural conditions. Apparent (directly measured) and inverted resistivity’s variation during the rainy event highlights some interesting zones. They could be interpreted as preferential pathways, where water dynamic seems quicker in term of moistening and drainage. Nevertheless, these results have to be interpreted reasonably because ERT does not provide enough precision to determine exact pathways geometry and functioning. In addition, forward modeling provided relevant data treatment limitations mainly for the deeper parts of the sections.
Hydrogeological and Environmental Investigations in Karst Systems
Springer Berlin Heidelberg