Representing lateral groundwater flow from land to river in Earth system models

<p>Lateral groundwater flow (LGF) is an important hydrologic process in controlling water table dynamics. Due to the relatively coarse spatial resolutions of land surface models, the representation of this process is often overlooked or overly simplified. In this study, we developed a hillslop...

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Main Authors: C. Liao, L. R. Leung, Y. Fang, T. Tesfa, R. Negron-Juarez
Format: Article
Language:English
Published: Copernicus Publications 2025-07-01
Series:Geoscientific Model Development
Online Access:https://gmd.copernicus.org/articles/18/4601/2025/gmd-18-4601-2025.pdf
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author C. Liao
L. R. Leung
Y. Fang
T. Tesfa
R. Negron-Juarez
author_facet C. Liao
L. R. Leung
Y. Fang
T. Tesfa
R. Negron-Juarez
author_sort C. Liao
collection DOAJ
description <p>Lateral groundwater flow (LGF) is an important hydrologic process in controlling water table dynamics. Due to the relatively coarse spatial resolutions of land surface models, the representation of this process is often overlooked or overly simplified. In this study, we developed a hillslope-based lateral groundwater flow model. Specifically, we first developed a hillslope definition model based on an existing watershed delineation model to represent the subgrid spatial variability in topography. Building upon this hillslope definition, we then developed a physical-based lateral groundwater flow using Darcy’s equation. This model explicitly considers the relationships between the groundwater table along the hillslope and the river water table levels. We coupled this intra-grid model to the land component (E3SM Land Model: ELM) and river component (MOdel for Scale Adaptive River Transport: MOSART) of the Energy Exascale Earth System Model (E3SM). We tested both the hillslope definition model and the lateral groundwater flow model and performed sensitivity experiments using different configurations. Simulations for a single grid cell at <span class="inline-formula">0.5<i>°</i>×0.5<i>°</i></span> within the Amazon basin show that the definition of hillslope is the key to modeling lateral flow processes and the runoff partition between surface and subsurface can be dramatically changed using the hillslope approach. Although our method provides a pathway to improve the lateral flow process, future improvements are needed to better capture the subgrid structure to account for the spatial variability in hillslopes within the simulated grid of land surface models.</p>
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institution Kabale University
issn 1991-959X
1991-9603
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publishDate 2025-07-01
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series Geoscientific Model Development
spelling doaj-art-1a1d7bb9eba84e3f9875ba06cfd4d40a2025-08-20T03:31:52ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032025-07-01184601462410.5194/gmd-18-4601-2025Representing lateral groundwater flow from land to river in Earth system modelsC. Liao0L. R. Leung1Y. Fang2T. Tesfa3R. Negron-Juarez4Atmospheric, Climate, and Earth Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USAAtmospheric, Climate, and Earth Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USAEnergy and Environment Division, Pacific Northwest National Laboratory, Richland, WA, USAEnergy and Environment Division, Pacific Northwest National Laboratory, Richland, WA, USAClimate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA<p>Lateral groundwater flow (LGF) is an important hydrologic process in controlling water table dynamics. Due to the relatively coarse spatial resolutions of land surface models, the representation of this process is often overlooked or overly simplified. In this study, we developed a hillslope-based lateral groundwater flow model. Specifically, we first developed a hillslope definition model based on an existing watershed delineation model to represent the subgrid spatial variability in topography. Building upon this hillslope definition, we then developed a physical-based lateral groundwater flow using Darcy’s equation. This model explicitly considers the relationships between the groundwater table along the hillslope and the river water table levels. We coupled this intra-grid model to the land component (E3SM Land Model: ELM) and river component (MOdel for Scale Adaptive River Transport: MOSART) of the Energy Exascale Earth System Model (E3SM). We tested both the hillslope definition model and the lateral groundwater flow model and performed sensitivity experiments using different configurations. Simulations for a single grid cell at <span class="inline-formula">0.5<i>°</i>×0.5<i>°</i></span> within the Amazon basin show that the definition of hillslope is the key to modeling lateral flow processes and the runoff partition between surface and subsurface can be dramatically changed using the hillslope approach. Although our method provides a pathway to improve the lateral flow process, future improvements are needed to better capture the subgrid structure to account for the spatial variability in hillslopes within the simulated grid of land surface models.</p>https://gmd.copernicus.org/articles/18/4601/2025/gmd-18-4601-2025.pdf
spellingShingle C. Liao
L. R. Leung
Y. Fang
T. Tesfa
R. Negron-Juarez
Representing lateral groundwater flow from land to river in Earth system models
Geoscientific Model Development
title Representing lateral groundwater flow from land to river in Earth system models
title_full Representing lateral groundwater flow from land to river in Earth system models
title_fullStr Representing lateral groundwater flow from land to river in Earth system models
title_full_unstemmed Representing lateral groundwater flow from land to river in Earth system models
title_short Representing lateral groundwater flow from land to river in Earth system models
title_sort representing lateral groundwater flow from land to river in earth system models
url https://gmd.copernicus.org/articles/18/4601/2025/gmd-18-4601-2025.pdf
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AT rnegronjuarez representinglateralgroundwaterflowfromlandtoriverinearthsystemmodels