Tracing and hydraulic modelling to assess the hydraulic performance of a constructed wetland

<p>Constructed wetlands are widely used to protect sensitive water resources from non-point source pollution from agriculture. Their potential to remove nitrate and pesticides increases with the water residence time and a uniform distribution of the inflow over the wetland area. Over the hydro...

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Main Authors: B. J. Lemaire, C. Chaumont, J. Tournebize, H. Henine
Format: Article
Language:English
Published: Copernicus Publications 2024-04-01
Series:Proceedings of the International Association of Hydrological Sciences
Online Access:https://piahs.copernicus.org/articles/385/135/2024/piahs-385-135-2024.pdf
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author B. J. Lemaire
B. J. Lemaire
C. Chaumont
J. Tournebize
H. Henine
author_facet B. J. Lemaire
B. J. Lemaire
C. Chaumont
J. Tournebize
H. Henine
author_sort B. J. Lemaire
collection DOAJ
description <p>Constructed wetlands are widely used to protect sensitive water resources from non-point source pollution from agriculture. Their potential to remove nitrate and pesticides increases with the water residence time and a uniform distribution of the inflow over the wetland area. Over the hydrological season, inflow variations greatly modify the theoretical residence time. The knowledge of the corresponding variations of the hydraulic performance constitutes a gap for the better management of treatment wetlands, especially for wetland with heterogeneous vegetation implementation. The aim of this work is to investigate how the hydraulic performance changes with the flow rate in a partly vegetated wetland. The study site, a 0.5 ha wetland, is located in an area of intensive cereal crop production in Northern France. The three-dimensional hydrodynamic model Delft3D-Flow was used to simulate flow through vegetation, forced by observed meteorological conditions. It was calibrated on continuous outflow concentration measurements and unmanned aerial vehicle (UAV) images during a 13 d tracing experiment with rhodamine WT. The simulated hydraulic performance indicators matched satisfactorily with observed values thanks to the detailed description of the vegetation. Simulations for the locally usual flow range and for a fixed water depth showed a limited increase of the hydraulic performance with the flow rate. This shows that conducting a tracing at low flow is sufficient to assess the average hydraulic performance of a wetland.</p>
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spelling doaj.art-8eb2ecfd77624094a5e23f112fac3ee82024-04-18T09:04:16ZengCopernicus PublicationsProceedings of the International Association of Hydrological Sciences2199-89812199-899X2024-04-0138513514010.5194/piahs-385-135-2024Tracing and hydraulic modelling to assess the hydraulic performance of a constructed wetlandB. J. Lemaire0B. J. Lemaire1C. Chaumont2J. Tournebize3H. Henine4Université Paris-Saclay, INRAE, Hydrosystèmes Continentaux Anthropisés – Ressources, Risques, Restauration, 92761, Antony, FranceUniversité Paris-Saclay, AgroParisTech, 75005, Paris, FranceUniversité Paris-Saclay, INRAE, Hydrosystèmes Continentaux Anthropisés – Ressources, Risques, Restauration, 92761, Antony, FranceUniversité Paris-Saclay, INRAE, Hydrosystèmes Continentaux Anthropisés – Ressources, Risques, Restauration, 92761, Antony, FranceUniversité Paris-Saclay, INRAE, Hydrosystèmes Continentaux Anthropisés – Ressources, Risques, Restauration, 92761, Antony, France<p>Constructed wetlands are widely used to protect sensitive water resources from non-point source pollution from agriculture. Their potential to remove nitrate and pesticides increases with the water residence time and a uniform distribution of the inflow over the wetland area. Over the hydrological season, inflow variations greatly modify the theoretical residence time. The knowledge of the corresponding variations of the hydraulic performance constitutes a gap for the better management of treatment wetlands, especially for wetland with heterogeneous vegetation implementation. The aim of this work is to investigate how the hydraulic performance changes with the flow rate in a partly vegetated wetland. The study site, a 0.5 ha wetland, is located in an area of intensive cereal crop production in Northern France. The three-dimensional hydrodynamic model Delft3D-Flow was used to simulate flow through vegetation, forced by observed meteorological conditions. It was calibrated on continuous outflow concentration measurements and unmanned aerial vehicle (UAV) images during a 13 d tracing experiment with rhodamine WT. The simulated hydraulic performance indicators matched satisfactorily with observed values thanks to the detailed description of the vegetation. Simulations for the locally usual flow range and for a fixed water depth showed a limited increase of the hydraulic performance with the flow rate. This shows that conducting a tracing at low flow is sufficient to assess the average hydraulic performance of a wetland.</p>https://piahs.copernicus.org/articles/385/135/2024/piahs-385-135-2024.pdf
spellingShingle B. J. Lemaire
B. J. Lemaire
C. Chaumont
J. Tournebize
H. Henine
Tracing and hydraulic modelling to assess the hydraulic performance of a constructed wetland
Proceedings of the International Association of Hydrological Sciences
title Tracing and hydraulic modelling to assess the hydraulic performance of a constructed wetland
title_full Tracing and hydraulic modelling to assess the hydraulic performance of a constructed wetland
title_fullStr Tracing and hydraulic modelling to assess the hydraulic performance of a constructed wetland
title_full_unstemmed Tracing and hydraulic modelling to assess the hydraulic performance of a constructed wetland
title_short Tracing and hydraulic modelling to assess the hydraulic performance of a constructed wetland
title_sort tracing and hydraulic modelling to assess the hydraulic performance of a constructed wetland
url https://piahs.copernicus.org/articles/385/135/2024/piahs-385-135-2024.pdf
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