Simulating 3D density-dependent groundwater flow: the adapted MOC3D
Oude Essink, G.H.P. (1999). Simulating 3D density-dependent groundwater flow: the adapted MOC3D. Natuurwet. Tijdschr. 79(1-4): 69-79 In: Natuurwetenschappelijk Tijdschrift. L. Walschot/Natuur- en Geneeskundige Vennootschap: Gent. ISSN 0770-1748, more Also appears in:De Breuck, W.; Walschot, L. (Ed.) (1999). Proceedings of the 15th Salt-Water Intrusion Meeting Ghent (Belgium), 25-29 May 1998. Natuurwetenschappelijk Tijdschrift, 79(1-4). Natuurwetenschappelijk Tijdschrift: Gent. 307 pp., more |  |
| Keywords | Density dependence
Models > Mathematical models
Water > Ground water
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| Abstract | In this paper, the three-dimensional (3D) computer code MOC3D (KONIKOW et al., 1996) is adapted for density differences MOCDENS3D. As a result, it is possible to simulate transient groundwater flow in large-scale 3D hydrogeologic systems where non-uniform density distributions occur. The groundwater-flow equation is solved by a module, which is in fact the MODFLOW computer code. Density differences are taken into account by adding buoyancy terms to the right-hand-side-term of the basic equation of MODFLOW. The advection-dispersion equation is solved by the MOC module, using the method of characteristics. An advantage of applying the method of characteristics is that the condition of spatial discretization, characterized by the so-called grid Peclet number, is not strict. As a consequence, the displacement of fresh, brackish and saline groundwater in large-scale 3D hydrogeologic systems can easily be simulated without severe numerical implications such as non-convergence as well as heavy over- and undershooting. In this paper, the evolution of a fresh-water lens in a phreatic aquifer is briefly discussed. |
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