1. General Model Information

Name: TRIM-3D

Acronym: TRIM-3D

Main medium: aquatic
Main subject: hydrology
Organization level: Landscape,ecosystem
Type of model: partial differential equations (3D)
Main application:
Keywords: lagoon of venice, flow, tidal flats


Dr. Vincenzo Casulli and Dr. Enrico Bertolazzi
Dept. Civil and Env. Engineering
Trento, Italy
Phone: +49 461 882676
Fax : +49 461 882672
email: casulli@invax.science.umitin.it



The Lagoon of Venice (50 km2) consists of several inter-connected narrow channels with a maximum width of 1 km, and up to 50 m deep encircling large and flat shallow areas. A considerable portion of the water body consists of tidal flats, and proper numerical treatment of flooding and drying of these areas are essential. The model uses a semi-implicit finite difference formulation for the numerical solution of the three-dimensional Reynolds equations in which the pressure is assumed by hydrostatic. A minimal degree of implicitness has been indroduced in the finite-difference formula so that the resulting algorithm permits the use of large time steps at a minimal computational cost. This formulation includes the simulation of flooding and drying of tidal flats, and is fully vectorizable for an efficient implementation on modern vector computers. The Lagoon has been covered with a 642 by 827 by 200 finite-difference mesh of dx=dy=50m and with the maximum dz being 0.25 m. Thus, the total number of grid points is 108,754,800, but only 1,177,729 of these are active.
This fine computational mesh allows for a very accurate description of the tree-like structure of the main channels. The high computational efficiency of this method has made it possible to provide the fine details of circulation structure that previous studies were unable to obtain.

Model purpose
3-D model for Accurate Flow Simulation in the Lagoon Venice.

Source of the Abstract:
Joergensen S.E., B. Halling-Soerensen and S.N Nielsen (Edts.) 1996: Handbook of Environmental and Ecological Modelling. CRC Press Boca Raton et al. 672 pp.

II. Technical Information

II.1 Executables:

Operating System(s): DOS, UNIX

II.2 Source-code:

Programming Language(s):

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

III.2.2 Output

IV. References

Casulli, V., 1990. Semi-implicit finite difference methods for the two- dimensional shallow water equations. J. of Computational Physics, Vol. 86, No. 1, pp. 56-74, 1990.
Casulli, V., and Cattani, E., 1994. Stability, accuracy and efficiency of a semi-implicit method for three-dimensional shallow water flow, Computers & Mathematics with Applications, Vol. 27, No. 4, pp. 99-112, 1994.
Casulli, V., and Cheng, R.T., 1992. Semi-implicit finite difference methods for three-dimensional shalluw water flow. Int. J. Numerical Methods in Fluids, Vol. 15, pp. 629-648, 1992.
Cheng, R.T., Casulli, V., and Gartner, J. W., Tidal, Residual, Inter-tidal Mud-flat (TRIM) model with applications to San Francisco Bay. Estuarine, Coastal Shelf Scienc, Vol. 36, pp. 235-280.

V. Further information in the World-Wide-Web

VI. Additional remarks

Last review of this document by: T. Gabele: Sep 23 1998
Status of the document: -
last modified by Tobias Gabele Wed Aug 21 21:44:51 CEST 2002

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