The Significance of Vertical and Lateral Groundwater–Surface Water Exchange Fluxes in Riverbeds and Riverbanks: Comparing 1D Analytical Flux Estimates with 3D Groundwater Modelling

Riverbed temperature profiles are frequently used to estimate vertical river–aquifer exchange fluxes. Often in this approach, strictly vertical flow is assumed. However, riverbeds are heterogeneous structures often characterised by complex flow fields, possibly violating this assumption. We characte...

Full description

Bibliographic Details
Main Authors: Gert Ghysels, Christian Anibas, Henock Awol, Abebe Debele Tolche, Uwe Schneidewind, Marijke Huysmans
Format: Article
Language:English
Published: MDPI AG 2021-01-01
Series:Water
Subjects:
Online Access:https://www.mdpi.com/2073-4441/13/3/306
_version_ 1797406875950514176
author Gert Ghysels
Christian Anibas
Henock Awol
Abebe Debele Tolche
Uwe Schneidewind
Marijke Huysmans
author_facet Gert Ghysels
Christian Anibas
Henock Awol
Abebe Debele Tolche
Uwe Schneidewind
Marijke Huysmans
author_sort Gert Ghysels
collection DOAJ
description Riverbed temperature profiles are frequently used to estimate vertical river–aquifer exchange fluxes. Often in this approach, strictly vertical flow is assumed. However, riverbeds are heterogeneous structures often characterised by complex flow fields, possibly violating this assumption. We characterise the meter-scale variability of river–aquifer interaction at two sections of the Aa River, Belgium, and compare vertical flux estimates obtained with a 1D analytical solution to the heat transport equation with fluxes simulated with a 3D groundwater model (MODFLOW) using spatially distributed fields of riverbed hydraulic conductivity. Based on 115 point-in-time riverbed temperature profiles, vertical flux estimates that are obtained with the 1D solution are found to be higher near the banks than in the center of the river. The total exchange flux estimated with the 3D groundwater model is around twice as high as the estimate based on the 1D solution, while vertical flux estimates from both methods are within a 10% margin. This is due to an important contribution of non-vertical flows, especially through the riverbanks. Quasi-vertical flow is only found near the center of the river. This quantitative underestimation should be considered when interpreting exchange fluxes based on 1D solutions. More research is necessary to assess conditions for which using a 1D analytical approach is justified to more accurately characterise river–aquifer exchange fluxes.
first_indexed 2024-03-09T03:33:00Z
format Article
id doaj.art-ef26dcb78516414b87985608b7b54261
institution Directory Open Access Journal
issn 2073-4441
language English
last_indexed 2024-03-09T03:33:00Z
publishDate 2021-01-01
publisher MDPI AG
record_format Article
series Water
spelling doaj.art-ef26dcb78516414b87985608b7b542612023-12-03T14:53:30ZengMDPI AGWater2073-44412021-01-0113330610.3390/w13030306The Significance of Vertical and Lateral Groundwater–Surface Water Exchange Fluxes in Riverbeds and Riverbanks: Comparing 1D Analytical Flux Estimates with 3D Groundwater ModellingGert Ghysels0Christian Anibas1Henock Awol2Abebe Debele Tolche3Uwe Schneidewind4Marijke Huysmans5Department of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, BelgiumConnected Waters Initiative Research Centre, UNSW Sydney, Sydney, NSW 2052, AustraliaInstitute of Technology, Wollo University, Kombolcha, EthiopiaSchool of Water Resources and Environmental Engineering, Haramaya Institute of Technology, Haramaya University, Dire Dawa 138, EthiopiaSchool of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UKDepartment of Hydrology and Hydraulic Engineering, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, BelgiumRiverbed temperature profiles are frequently used to estimate vertical river–aquifer exchange fluxes. Often in this approach, strictly vertical flow is assumed. However, riverbeds are heterogeneous structures often characterised by complex flow fields, possibly violating this assumption. We characterise the meter-scale variability of river–aquifer interaction at two sections of the Aa River, Belgium, and compare vertical flux estimates obtained with a 1D analytical solution to the heat transport equation with fluxes simulated with a 3D groundwater model (MODFLOW) using spatially distributed fields of riverbed hydraulic conductivity. Based on 115 point-in-time riverbed temperature profiles, vertical flux estimates that are obtained with the 1D solution are found to be higher near the banks than in the center of the river. The total exchange flux estimated with the 3D groundwater model is around twice as high as the estimate based on the 1D solution, while vertical flux estimates from both methods are within a 10% margin. This is due to an important contribution of non-vertical flows, especially through the riverbanks. Quasi-vertical flow is only found near the center of the river. This quantitative underestimation should be considered when interpreting exchange fluxes based on 1D solutions. More research is necessary to assess conditions for which using a 1D analytical approach is justified to more accurately characterise river–aquifer exchange fluxes.https://www.mdpi.com/2073-4441/13/3/306groundwater–surface water interactiontemperaturehydraulic conductivityheterogeneityMODFLOWBelgium
spellingShingle Gert Ghysels
Christian Anibas
Henock Awol
Abebe Debele Tolche
Uwe Schneidewind
Marijke Huysmans
The Significance of Vertical and Lateral Groundwater–Surface Water Exchange Fluxes in Riverbeds and Riverbanks: Comparing 1D Analytical Flux Estimates with 3D Groundwater Modelling
Water
groundwater–surface water interaction
temperature
hydraulic conductivity
heterogeneity
MODFLOW
Belgium
title The Significance of Vertical and Lateral Groundwater–Surface Water Exchange Fluxes in Riverbeds and Riverbanks: Comparing 1D Analytical Flux Estimates with 3D Groundwater Modelling
title_full The Significance of Vertical and Lateral Groundwater–Surface Water Exchange Fluxes in Riverbeds and Riverbanks: Comparing 1D Analytical Flux Estimates with 3D Groundwater Modelling
title_fullStr The Significance of Vertical and Lateral Groundwater–Surface Water Exchange Fluxes in Riverbeds and Riverbanks: Comparing 1D Analytical Flux Estimates with 3D Groundwater Modelling
title_full_unstemmed The Significance of Vertical and Lateral Groundwater–Surface Water Exchange Fluxes in Riverbeds and Riverbanks: Comparing 1D Analytical Flux Estimates with 3D Groundwater Modelling
title_short The Significance of Vertical and Lateral Groundwater–Surface Water Exchange Fluxes in Riverbeds and Riverbanks: Comparing 1D Analytical Flux Estimates with 3D Groundwater Modelling
title_sort significance of vertical and lateral groundwater surface water exchange fluxes in riverbeds and riverbanks comparing 1d analytical flux estimates with 3d groundwater modelling
topic groundwater–surface water interaction
temperature
hydraulic conductivity
heterogeneity
MODFLOW
Belgium
url https://www.mdpi.com/2073-4441/13/3/306
work_keys_str_mv AT gertghysels thesignificanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT christiananibas thesignificanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT henockawol thesignificanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT abebedebeletolche thesignificanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT uweschneidewind thesignificanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT marijkehuysmans thesignificanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT gertghysels significanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT christiananibas significanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT henockawol significanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT abebedebeletolche significanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT uweschneidewind significanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling
AT marijkehuysmans significanceofverticalandlateralgroundwatersurfacewaterexchangefluxesinriverbedsandriverbankscomparing1danalyticalfluxestimateswith3dgroundwatermodelling