Development of a fast computer code for salt-water/fresh-water movement in large complex heterogeneous three-dimensional groundwater systems: background, features and applications
Fein, E.; Schelkes, K. (1999). Development of a fast computer code for salt-water/fresh-water movement in large complex heterogeneous three-dimensional groundwater systems: background, features and applications. Natuurwet. Tijdschr. 79(1-4): 48-54 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 | Models > Mathematical models Water > Fresh water Water > Ground water Water > Saline water Germany [Marine Regions] Marine/Coastal; Fresh water |
Abstract | Sedimentary rocks and salt formations have been selected in Germany as geologic host media for repositories for radioactive or toxic wastes. Commonly the salinity of the water at those sites generally increases with depth, often up to saturated brine at considerable depth. Flow models have to take into account the salt-dependent density of the water, which is strongly influencing the flow field. They have to deal with the solution of strongly non-linear coupled three-dimensional partial differential equations. In addition, heterogeneities and anisotropies have to be considered for realistic time-dependent modelling of the regional hydrogeology at these sites. In the past, it was not possible to model such complex systems with the available soft- and hardware. The variable density was taken into account only in two-dimensional cross-sectional models. In three-dimensional mode's generally the simplification of a constant water density was assumed. To overcome these difficulties the new fast computer code d³f (distributed density driven flow) was developed. Some specific features are: structure contour maps as input data, hydrogeological parameters as spatial functions, graphically interactive pre- and post-processing tools, and, most important, the mathematical features: linear and non-linear strategies based on unstructured grids, adaptivity in space and time, and parallel computing. The code showed its efficiency in first applications |
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