Do thermal infrared (TIR) remote sensing and direct hyporheic measurements (DHM) similarly detect river-groundwater exchanges? Study along a 40 km-section of the Ain River (France)

Abstract : Water exchanges through the hyporheic zone are crucial to many ecological processes in streams. One major challenge for river managers is to find a practical method for localizing these exchanges using rapid data acquisition techniques. This work compares spatially continuous data, acquired by Thermal Infrared (TIR) techniques, with discrete data collected in surface water and in the hyporheic zone (DHM), at sites of expected water exchanges (gravel bars). Forty gravel bars, distributed along a 40 km-sector of the Ain River were sampled at upstream- and downstream-bar positions (80 sites) in order to reveal hyporheic exchanges. At each site, 4 physico-chemical parameters were measured at 0, −20 and –50 cm beneath the sediment surface. The field collections of TIR high-resolution images were conducted concomitantly, at low flow and high surface-water temperatures. Among the 80 sites selected for field measurements, 14 were identified as upwellings (groundwater inputs) and 66 as downwelling sites. From those 14 upwellings, 13 were also identified with TIR. The 44 additional sites identified with TIR corresponded to small-sized cold-water patches situated along the gravel bars or to groundwater discharge sites located between the bars (19 lateral seeps). Nevertheless, the DHM method documented on downwelling exchanges (infiltration of surface water), which were not captured by TIR images, and may represent hyporheic hotspots especially for benthic invertebrates. Along the studied sector of the Ain River, these downwelling zones were much more numerous than upwelling ones. Both methods in combination provide a rather complete picture of water exchange along rivers and are needed to evaluate the potential as refuges zones during critical dry periods.
Type de document :
Article dans une revue
Science of the Total Environment, Elsevier, 2019, 646, pp.1097 - 1110. 〈10.1016/j.scitotenv.2018.07.294〉
Liste complète des métadonnées

https://hal.archives-ouvertes.fr/hal-01877175
Contributeur : Nathalie Lyvet <>
Soumis le : mercredi 19 septembre 2018 - 14:15:28
Dernière modification le : lundi 19 novembre 2018 - 11:43:23

Identifiants

Citation

Marie-José Dole-Olivier, Vincent Wawzyniak, Michel Creuzé Des Chatelliers, Pierre Marmonier. Do thermal infrared (TIR) remote sensing and direct hyporheic measurements (DHM) similarly detect river-groundwater exchanges? Study along a 40 km-section of the Ain River (France). Science of the Total Environment, Elsevier, 2019, 646, pp.1097 - 1110. 〈10.1016/j.scitotenv.2018.07.294〉. 〈hal-01877175〉

Partager

Métriques

Consultations de la notice

56