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Article Dans Une Revue Journal of Hydrology Année : 2022

Implementation of subsurface transport processes in the low-dimensional integrated hydrological model NIHM

Résumé

Solute transport models based on the resolution of the 3-D Advection-Dispersion (AD) equation are frequently plagued by several numerical problems, which add to the high computational cost. The hydrological model NIHM (Normally Integrated Hydrological Model) was recently proposed as a tool simulating the hydrological responses of watersheds with shallow saturated aquifers by coupling surface flow and a low-dimensional subsurface system, including the vadose zone. In this paper, we couple the low-dimensional flow model NIHM with a transport module solving the AD to propose an approach that enables to reduce the dimensionality of both the flow and transport problems. In NIHM, the low-dimensionality in the subsurface compartment results from an integration along the local direction normal to the bedrock of the aquifer. NIHM was previously evaluated and applied to actual hydrosystems-without addressing mass transfers-and it showed its ability to capture various hydrological responses even from complex systems. However, the relevance of a low-dimensional approach to transport is not proven yet as the model reduction could also render approximated velocity fields inappropriate to mass transfer problems. The accuracy and computational efficiency of the proposed model have been thoroughly examined through various synthetic test cases under different hydrodynamic conditions to assess the influence of the reduction of dimensionality on solute transport simulations. The findings of this study demonstrate that the reduction of dimension remains suited to predicting solute transport behaviors in shallow subsurface systems while providing an important gain in computation time. This might be promising for various applications dealing with groundwater quality.

Dates et versions

insu-04471410 , version 1 (21-02-2024)

Identifiants

Citer

Mouna Chaguer, Sylvain Weill, Philippe Ackerer, Frederick Delay. Implementation of subsurface transport processes in the low-dimensional integrated hydrological model NIHM. Journal of Hydrology, 2022, 609, ⟨10.1016/j.jhydrol.2022.127696⟩. ⟨insu-04471410⟩
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