|WORLD METEOROLOGICAL ORGANIZATION||
|Explanation of the criteria for classification and numbering of components|| L20.3.13
|Explanation of the dates on the component's description|
COMPLETE PROGRAM PACKAGE FOR MODELLING GROUNDWATER FLOW (TRIWACO)
1. Purpose and objectives
A package for modelling saturated and unsaturated groundwater flow,
based on the finite element method. To calculate the heads, fluxes and path lines in heterogeneous anisotropic multi-aquifer systems.
The flow is described by Darcy's law and the mass continuity equation. The Galerkin finite element method is used to approximate the differential equations as a set of algebraic equations, which are then solved by the conjugate gradient method. Both steady-state and transient systems can be modelled.
The system can handle the following cases:
Multi-layered aquifer-aquitard system, neglecting vertical resistance within aquifers and assuming vertical flow in aquitards. Fully 3-D schematisation by using up to 99 model aquifers as layers and
The TRIWACO package consists of several separate programs:
- TESNET to generate the finite element grid (triangles including
Hydrogeologic parameters, wells, rivers, recharge rate, boundary and initial conditions, and finite element grid structure.
Heads for all aquifers and fluxes through all aquitards, fluxes to rivers, wells, top-systems and through boundaries. All data is stored in standard datasets which are very easy to use in pre-processing programs or for re-inputting. Several pre-processing programs can be used for viewing
5. Operational requirements and restrictions
IBM compatible personal computer with 640 K memory, mathematical coprocessor and a hard disc. It is recommended having a 80386-processor or higher. The Graphical Kernel System for printing results includes drivers for most plotters and printers. The package is available on PC (DOS, WINDOWS and OS/2) as well as on mainframes (UNIX). The user-friendly WINDOWS version is available from the end of 1996.
Easy installation according to manual. Requires a short time to
acquire proficiency in handling. As the FORTRAN 77 source code is not supplied, no FORTRAN compiler is needed by the user.
6. Form of presentation
Run version of the computer program package on a number of floppy disks. A comprehensive users manual in English.
7. Operational experience
The model has been widely used in The Netherlands since 1988. Many water supply companies and regional authorities have TRIWACO
models for (operationally orientated) groundwater investigations.
It has also been used in other countries like Hungary, Egypt, Indonesia, Belgium, Germany.
8. Originator and technical support
IWACO B.V., Consultants for water and environment, Rotterdam, The Netherlands.
10. Conditions on use
A charge will be made for supplying the model. Updates of the new run versions will be forwarded to users automatically during a certain period of time.
|(First entered: 31 JULY 01||
Last updated: 19 JAN 98)