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Improved water table dynamics in MODFLOW
Author(s) -
Clemo Tom
Publication year - 2005
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/j.1745-6584.2005.0021.x
Subject(s) - water table , modflow , table (database) , aquifer , node (physics) , flow (mathematics) , water flow , lookup table , geology , groundwater , computer science , groundwater flow , geotechnical engineering , mathematics , geometry , engineering , structural engineering , data mining , programming language
The standard formulation of a block‐centered finite‐difference model, such as MODFLOW, uses the center of the cell as the location of a cell node. Simulations of a dynamic water table can be improved if the node of a cell containing the water table is located at the water table rather than at the center of the cell. The LPF package of MOD‐FLOW‐2000 was changed to position a cell's node at the water table in convertible cells with a water table. Improved accuracy in the upper regions of an unconfined aquifer is demonstrated for pumping from a partially penetrating well. The change introduces a nonlinearity into the solution of the flow equations that results in slightly slower convergence of the flow solution, 7% slower in the presented demonstration. Accuracy of simulations is improved where vertical flow is dominated by a moving water table, but not when a large water table gradient dominates over the water table movement.