Boumaiza Lamine, Chesnaux Romain, Walter Julien et Stumpp Christine. (2020). Constraining a flow model with field measurements to assess water transit time through a vadose zone. Groundwater,
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URL officielle: http://dx.doi.org/doi:10.1111/gwat.13056
Résumé
The modeling of thick vadose zones is particularly challenging because of difficulties in collecting a variety of measured sediment properties, which are required for parameterizing the model. Some models rely on synthetic data, whereas others are simplified by running as homogeneous sediment domains and relying on a single set of sediment properties. Few studies have simulated flow processes through a thick vadose zone using real and comprehensive data sets comprising multiple measurements. Here, we develop a flow model for a 7‐m‐thick vadose zone. This model, combining the numerical codes CTRAN/W with SEEP/W, includes the measured sediment hydraulic properties of the investigated vadose zone and incorporates the actual climate and subsurface conditions of the study site (precipitations, water‐table elevations, and stable isotope data). The model is calibrated by fitting the simulated and measured vertical profiles of water content. Our flow model calculates a transit time of 1 year for the travel of water through the 7‐m vadose zone; this estimate matches stable isotope‐based results obtained previously for this site. A homogeneous sediment domain flow model, which considers only a single set of sediment properties, produces a transit time that is approximately half the duration of that of the heterogeneous flow model. This difference highlights the importance of assuming heterogeneous material within models of thick vadose zones and testifies to the advantage gained when using real sediment hydraulic properties to parametrize a flow model.
Type de document: | Article publié dans une revue avec comité d'évaluation |
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Version évaluée par les pairs: | Oui |
Date: | 21 Octobre 2020 |
Sujets: | Sciences naturelles et génie > Génie Sciences naturelles et génie > Sciences appliquées Sciences naturelles et génie > Sciences naturelles > Sciences de la terre (géologie, géographie) |
Département, module, service et unité de recherche: | Départements et modules > Département des sciences appliquées > Unité d'enseignement en sciences de la Terre |
Mots-clés: | SEEP/W, CTRAN/W, water content, hydraulic conductivity, water table, teneur en eau, conductivité hydraulique, nappe phréatique |
Déposé le: | 27 janv. 2021 22:33 |
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Dernière modification: | 21 oct. 2021 04:10 |
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