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A Bayesian Assessment of an Approximate Model for Unconfined Water Flow in Sloping Layered Porous Media
The prediction of water table height in unconfined layered porous media is a difficult modelling problem that typically requires numerical simulation. This paper proposes an analytical model to approximate the exact solution based on a steady-state Dupuit–Forchheimer analysis. The key contribution i...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer Netherlands
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6390717/ https://www.ncbi.nlm.nih.gov/pubmed/30872878 http://dx.doi.org/10.1007/s11242-018-1094-2 |
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author | Chiachío, Juan Chiachío, Manuel Sankararaman, Shankar Prescott, Darren |
author_facet | Chiachío, Juan Chiachío, Manuel Sankararaman, Shankar Prescott, Darren |
author_sort | Chiachío, Juan |
collection | PubMed |
description | The prediction of water table height in unconfined layered porous media is a difficult modelling problem that typically requires numerical simulation. This paper proposes an analytical model to approximate the exact solution based on a steady-state Dupuit–Forchheimer analysis. The key contribution in relation to a similar model in the literature relies in the ability of the proposed model to consider more than two layers with different thicknesses and slopes, so that the existing model becomes a special case of the proposed model herein. In addition, a model assessment methodology based on the Bayesian inverse problem is proposed to efficiently identify the values of the physical parameters for which the proposed model is accurate when compared against a reference model given by MODFLOW-NWT, the open-source finite-difference code by the U.S. Geological Survey. Based on numerical results for a representative case study, the ratio of vertical recharge rate to hydraulic conductivity emerges as a key parameter in terms of model accuracy so that, when appropriately bounded, both the proposed model and MODFLOW-NWT provide almost identical results. |
format | Online Article Text |
id | pubmed-6390717 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Springer Netherlands |
record_format | MEDLINE/PubMed |
spelling | pubmed-63907172019-03-12 A Bayesian Assessment of an Approximate Model for Unconfined Water Flow in Sloping Layered Porous Media Chiachío, Juan Chiachío, Manuel Sankararaman, Shankar Prescott, Darren Transp Porous Media Article The prediction of water table height in unconfined layered porous media is a difficult modelling problem that typically requires numerical simulation. This paper proposes an analytical model to approximate the exact solution based on a steady-state Dupuit–Forchheimer analysis. The key contribution in relation to a similar model in the literature relies in the ability of the proposed model to consider more than two layers with different thicknesses and slopes, so that the existing model becomes a special case of the proposed model herein. In addition, a model assessment methodology based on the Bayesian inverse problem is proposed to efficiently identify the values of the physical parameters for which the proposed model is accurate when compared against a reference model given by MODFLOW-NWT, the open-source finite-difference code by the U.S. Geological Survey. Based on numerical results for a representative case study, the ratio of vertical recharge rate to hydraulic conductivity emerges as a key parameter in terms of model accuracy so that, when appropriately bounded, both the proposed model and MODFLOW-NWT provide almost identical results. Springer Netherlands 2018-06-09 2019 /pmc/articles/PMC6390717/ /pubmed/30872878 http://dx.doi.org/10.1007/s11242-018-1094-2 Text en © The Author(s) 2018 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
spellingShingle | Article Chiachío, Juan Chiachío, Manuel Sankararaman, Shankar Prescott, Darren A Bayesian Assessment of an Approximate Model for Unconfined Water Flow in Sloping Layered Porous Media |
title | A Bayesian Assessment of an Approximate Model for Unconfined Water Flow in Sloping Layered Porous Media |
title_full | A Bayesian Assessment of an Approximate Model for Unconfined Water Flow in Sloping Layered Porous Media |
title_fullStr | A Bayesian Assessment of an Approximate Model for Unconfined Water Flow in Sloping Layered Porous Media |
title_full_unstemmed | A Bayesian Assessment of an Approximate Model for Unconfined Water Flow in Sloping Layered Porous Media |
title_short | A Bayesian Assessment of an Approximate Model for Unconfined Water Flow in Sloping Layered Porous Media |
title_sort | bayesian assessment of an approximate model for unconfined water flow in sloping layered porous media |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6390717/ https://www.ncbi.nlm.nih.gov/pubmed/30872878 http://dx.doi.org/10.1007/s11242-018-1094-2 |
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