Description of and User's Manual for a Finite Element Aquifer Flow Model AQUIFEM-1
Prepared with the support of the Agency for International Development, U.S. Dept. of State.
| Main Authors: | , |
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| Published: |
Cambridge, Mass. : Massachusetts Institute of Technology, Dept. of Civil Engineering, Ralph M. Parsons Laboratory for Water Resources and Hydrodynamics
2022
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| Online Access: | https://hdl.handle.net/1721.1/143001 |
| _version_ | 1811073629690003456 |
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| author | Townley, Lloyd R. Wilson, John L. |
| author_facet | Townley, Lloyd R. Wilson, John L. |
| author_sort | Townley, Lloyd R. |
| collection | MIT |
| description | Prepared with the support of the Agency for International Development, U.S. Dept. of State. |
| first_indexed | 2024-09-23T09:36:01Z |
| id | mit-1721.1/143001 |
| institution | Massachusetts Institute of Technology |
| last_indexed | 2024-09-23T09:36:01Z |
| publishDate | 2022 |
| publisher | Cambridge, Mass. : Massachusetts Institute of Technology, Dept. of Civil Engineering, Ralph M. Parsons Laboratory for Water Resources and Hydrodynamics |
| record_format | dspace |
| spelling | mit-1721.1/1430012022-06-14T03:39:21Z Description of and User's Manual for a Finite Element Aquifer Flow Model AQUIFEM-1 Townley, Lloyd R. Wilson, John L. Prepared with the support of the Agency for International Development, U.S. Dept. of State. A detailed user's and programmer's manual for "AQUIFEM-1," a versatile two-dimensional finite element model for groundwater flow, is presented. The model is based on the hydraulic equations of essentially horizontal flow, but can also be used for the analysis of vertical cross-sectional flow. AQUIFEM-1 employs the Galerkin finite element technique, with linear interpolation functions and triangular elements. Leakage from an adjacent aquifer, pumping and recharge wells, flowing wells, lateral inflows and outflows, induced infiltration, rising water conditions, evapotranspiration and numerous other boundary conditions and sources/sinks are accounted for. Both steady state and transient solutions for confined, phreatic or mixed (changing status) aquifers can be computed. The report provides a review of the mathematical formulation of the model and a detailed description of its capacilities. Techniques are described for the simulation of springs, agricultural drainage, geologic faults, excavation dewatering, and other features of interest to the modeler. Numerous examples are given for horizontal flow models; there are also illustrations of vertical cross-sectional models. AQUIFEM-1 is based on any consistent set of units. It utilizes dynamic storage allocation. All input data are automatically checked for completeness and consistency, and appropriate messages generated. The code can be run in either time-sharing or batch modes. Output, which can be printed, print-plotted, or saved on file, includes a mimic of -the input and, at each time step, heads, drawdowns, flow rates, boundary fluxes, aquifer status, etc. The finite element matrix equations are solved in-core using a direct "skyline" equation solving algorithm based on Crout's method. All matrices are stored in vector form. Non-linear problems are handled with fixed-point iteration using one of several options that can be used to reduce computational costs. An example problem is used to illustrate model features and typical AQUIFEM-1 input and output. There is a detailed list of variables and description of input data requirements. The programmer's guide provides information on the structure of the program, to make it easier to implement modifications. A program listing is included. This report should be used in conjunction with Wilson, Townley and Sa da Costa [1979], which describes the mathematical development of AQUIFEM-1 and provides numerous illustrations of its application. 2022-06-13T13:08:37Z 2022-06-13T13:08:37Z 1980-02 252 https://hdl.handle.net/1721.1/143001 6679026 92543 R (Massachusetts Institute of Technology. Department of Civil Engineering) ; 80-5. Report (Ralph M. Parsons Laboratory for Water Resources and Hydrodynamics) ; 252. application/pdf Cambridge, Mass. : Massachusetts Institute of Technology, Dept. of Civil Engineering, Ralph M. Parsons Laboratory for Water Resources and Hydrodynamics |
| spellingShingle | Townley, Lloyd R. Wilson, John L. Description of and User's Manual for a Finite Element Aquifer Flow Model AQUIFEM-1 |
| title | Description of and User's Manual for a Finite Element Aquifer Flow Model AQUIFEM-1 |
| title_full | Description of and User's Manual for a Finite Element Aquifer Flow Model AQUIFEM-1 |
| title_fullStr | Description of and User's Manual for a Finite Element Aquifer Flow Model AQUIFEM-1 |
| title_full_unstemmed | Description of and User's Manual for a Finite Element Aquifer Flow Model AQUIFEM-1 |
| title_short | Description of and User's Manual for a Finite Element Aquifer Flow Model AQUIFEM-1 |
| title_sort | description of and user s manual for a finite element aquifer flow model aquifem 1 |
| url | https://hdl.handle.net/1721.1/143001 |
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