The mathematical model for unsaturated soil water movement is essentially the Richards equation, which is a time-dependent nonlinear partial differential equation. This paper proposes an upwind discontinuous finite volume element method (DFVEM) on triangular meshes for solving two-dimensional unsaturated soil water flow problems. By employing an upwind strategy for the convection term, the method effectively avoids numerical dispersion and non-physical oscillations while preserving the local mass conservation and flexibility of the standard DFVEM. The error estimates are derived in the $ L^2 $ norm and $ |\!|\!|\cdot|\!|\!|_{1, h} $ norm. Numerical experiments are conducted to verify the theoretical analysis and demonstrate the efficiency of the proposed method.
Citation: Fang Wang, Fan Chen, Changqing Lv, Xiaoyan Qin. An upwind discontinuous finite volume element method on triangular meshes for the two-dimensional unsaturated soil water movement problem[J]. AIMS Mathematics, 2026, 11(8): 24152-24178. doi: 10.3934/math.2026975
The mathematical model for unsaturated soil water movement is essentially the Richards equation, which is a time-dependent nonlinear partial differential equation. This paper proposes an upwind discontinuous finite volume element method (DFVEM) on triangular meshes for solving two-dimensional unsaturated soil water flow problems. By employing an upwind strategy for the convection term, the method effectively avoids numerical dispersion and non-physical oscillations while preserving the local mass conservation and flexibility of the standard DFVEM. The error estimates are derived in the $ L^2 $ norm and $ |\!|\!|\cdot|\!|\!|_{1, h} $ norm. Numerical experiments are conducted to verify the theoretical analysis and demonstrate the efficiency of the proposed method.
| [1] |
D. N. Arnold, An interior penalty finite element method with discontinuous elements, SIAM J. Numer. Anal., 19 (1982), 742–760. https://doi.org/10.1137/0719052 doi: 10.1137/0719052
|
| [2] | J. Bear, Dynamics of fluids in porous media, Dover: Dover Publications, 2013. |
| [3] |
C. Bi, J. Geng, Discontinuous finite volume element method for parabolic problems, Numer. Meth. Part. D. E., 26 (2010), 367–383. https://doi.org/10.1002/num.20437 doi: 10.1002/num.20437
|
| [4] |
D. Breit, T. C. Moyo, P. Öffner, Discontinuous Galerkin methods for the complete stochastic Euler equations, J. Comput. Phys., 541 (2025), 114324. https://doi.org/10.1016/j.jcp.2025.114324 doi: 10.1016/j.jcp.2025.114324
|
| [5] |
R. Bürger, S. Kumar, R. Ruiz-Baier, Discontinuous finite volume element discretization for coupled flow-transport problems arising in models of sedimentation, J. Comput. Phys., 299 (2015), 446–471. https://doi.org/10.1016/j.jcp.2015.07.020 doi: 10.1016/j.jcp.2015.07.020
|
| [6] |
F. Chen, M. Cui, C. Zhou, Sequential symmetric interior penalty discontinuous Galerkin method for fully coupled quasi-static thermo-poroelasticity problems, Comput. Math. Appl., 218 (2026), 67–88. https://doi.org/10.1016/j.camwa.2026.06.012 doi: 10.1016/j.camwa.2026.06.012
|
| [7] |
F. Chen, Z. Xu, Discontinuous finite volume element method of two-dimensional unsaturated soil water movement problem, Adv. Differ. Equ., 2019 (2019), 478. https://doi.org/10.1186/s13662-019-2395-7 doi: 10.1186/s13662-019-2395-7
|
| [8] |
S. H. Chou, X. Ye, Unified analysis of finite volume methods for second order elliptic problems, SIAM J. Numer. Anal., 45 (2007), 1639–1653. https://doi.org/10.1137/050643994 doi: 10.1137/050643994
|
| [9] |
C. N. Dawson, M. F. Wheeler, C. S. Woodward, A two-grid finite difference scheme for nonlinear parabolic equations, SIAM J. Numer. Anal., 35 (1998), 435–452. https://doi.org/10.1137/S0036142995293493 doi: 10.1137/S0036142995293493
|
| [10] |
R. Devi, D. N. Pandey, Discontinuous Galerkin methods for nonlinear parabolic delay-equations of nonmonotone type, J. Sci. Comput., 101 (2024), 50. https://doi.org/10.1007/s10915-024-02696-x doi: 10.1007/s10915-024-02696-x
|
| [11] |
Z. Di, Z. Luo, Z. Xie, A. Wang, I. M. Navon, An optimizing implicit difference scheme based on proper orthogonal decomposition for the two-dimensional unsaturated soil water flow equation, Int. J. Numer. Meth. Fluids, 68 (2012), 1324–1340. https://doi.org/10.1002/fld.2610 doi: 10.1002/fld.2610
|
| [12] |
F. Gao, Y. Yuan, An upwind finite volume element method based on quadrilateral meshes for nonlinear convection‐diffusion problems, Numer. Meth. Part. D. E., 25 (2009), 1067–1085. https://doi.org/10.1002/num.20387 doi: 10.1002/num.20387
|
| [13] |
H. R. Li, Z. D. Luo, Z. H. Xie, J. Zhu, Generalized difference methods and numerical simulation for unsaturated soil water flow problems (Chinese), Mathematica Numerica Sinica, 28 (2006), 321–336. https://doi.org/10.12286/jssx.2006.3.321 doi: 10.12286/jssx.2006.3.321
|
| [14] |
L. Li, Z. Zhou, A mass-conserved domain decomposition method for the unsaturated soil flow water problem, Adv. Differ. Equ., 2019 (2019), 272. https://doi.org/10.1186/s13662-019-2213-2 doi: 10.1186/s13662-019-2213-2
|
| [15] |
J. Li, J. Zeng, R. Li, An adaptive discontinuous finite volume element method for the Allen-Cahn equation, Adv. Comput. Math., 49 (2023), 55. https://doi.org/10.1007/s10444-023-10031-5 doi: 10.1007/s10444-023-10031-5
|
| [16] |
R. Li, Y. Gao, W. Yan, Z. Chen, A Crank-Nicolson discontinuous finite volume element method for a coupled non-stationary Stokes-Darcy problem, J. Comput. Appl. Math., 353 (2019), 86–112. https://doi.org/10.1016/j.cam.2018.12.025 doi: 10.1016/j.cam.2018.12.025
|
| [17] |
J. Liu, L. Mu, X. Ye, R. Jari, Convergence of the discontinuous finite volume method for elliptic problems with minimal regularity, J. Comput. Appl. Math., 236 (2012), 4537–4546. https://doi.org/10.1016/j.cam.2012.05.009 doi: 10.1016/j.cam.2012.05.009
|
| [18] |
Y. Liu, H. Yang, Z. Xie, P. Qin, R. Li, Parallel simulation of variably saturated soil water flows by fully implicit domain decomposition methods, J. Hydrol., 582 (2020), 124481. https://doi.org/10.1016/j.jhydrol.2020.124481 doi: 10.1016/j.jhydrol.2020.124481
|
| [19] |
M. Th. Van Genuchten, A closed-form equation for predicting the hydraulic conductivity of unsaturated soils, Soil Sci. Soc. Am. J., 44 (1980), 892–898. https://doi.org/10.2136/sssaj1980.03615995004400050002x doi: 10.2136/sssaj1980.03615995004400050002x
|
| [20] |
F. Wang, P. Wang, M. Zhao, C. Shan, Z. Yang, The power of modality: improving polyp segmentation with multimodal information, IET Image Process., 20 (2026), e70305. https://doi.org/10.1049/ipr2.70305 doi: 10.1049/ipr2.70305
|
| [21] |
X. Ye, A new discontinuous finite volume method for elliptic problems, SIAM J. Numer. Anal., 42 (2004), 1062–1072. https://doi.org/10.1137/S0036142902417042 doi: 10.1137/S0036142902417042
|
| [22] |
X. Ye, A discontinuous finite volume method for the Stokes problems, SIAM J. Numer. Anal., 44 (2006), 183–198. https://doi.org/10.1137/040616759 doi: 10.1137/040616759
|