1. General Model Information
Name: Computational Aquatic Ecosystem DYnamics Model
Main medium: aquatic
Main subject: ecology, other, biogeochemistry, population dynamics
Organization level: Ecosystem
Type of model: not specified (3D), difference equations (1D), partial differential equations (finite differences)
Main application: simulation/optimisation tool, research,
Keywords: ecosystem, water quality
Centre for Water Research, University of Western Australia
Phone: +61 8 9380 1684
Fax: +61 8 9380 1015
David Hamilton and Michael Herzfeld
The Computational Aquatic Ecosystem Dynamics Model (CAEDYM) is an aquatic ecological model
that may be run independently or coupled with hydrodynamic models DYRESM or ELCOM. CAEDYM
consists of a series of mathematical equations representing the major biogeochemical processes
influencing water quality. At its most basic, CAEDYM is a set of library subroutines that
contain process descriptions for primary production, secondary production, nutrient and metal
cycling, and oxygen dynamics and the movement of sediment.
CAEDYM configuration is flexible so that the user can focus on the processes of interest. For
example, the model can be configured for a simple set of nutrients-phytoplankton-zooplankton.
By simulating several state variables at the species level, CAEDYM can be used to support the
understanding and management of a system. In addition, the model can be coupled to the
one-dimensional hydrodynamic model (DYRESM) for studies of the seasonal, annual or decadal
variation in water quality. For more detailed spatial information, CAEDYM can be run with the
three-dimensional hydrodynamic model ELCOM. To maximize speed and memory requirements CAEDYM
shares a common internal data structure with both DYRESM and ELCOM. They also use common
output data storage formats, and share common Graphical User Interface (GUI) and visualization
routines for configuring the model and displaying the results.
DYRESM-CAEDYM is presently being used in 24 countries around the world. It can be downloaded
II. Technical Information
Operating System(s): Windows 95/98, Windows NT, Linux, DEC Unix, (MacOS X forthcoming)
Programming Language(s): Fortran 95
CAEDYM Science Manual; CAEDYM Users Manual; CAEDYM Programmers Manual
III. Mathematical Information
(All state variables can be optionally siwtched on or off)
Phytoplankton: up to seven groups
Dissolved Oxygen Biochemical Oxygen Demand ("fast" and "slow")
Nutrients (NH4, NO3, PO4, TP, TN and internal phytoplankton N, P and C)
Suspended Solids: two groups
Zooplankton: up to five groups
Fish: up to nine groups Jellyfish Seagrasses/Macrophytes
Macroinvertebrates (bivalves, polychaetes and crustacean grazers)
Metals: Iron, Manganese and Aluminium
- Initial concentrations of state variables.
- Inflows and concentrations in inflows and over forcing regions.
- Parameter values.
- Other data may be required by the hydrodynamic driver (DYRESM or ELCOM), e.g. meteorological forcing data.
- Time series of state variables and major influences on these (at a set point in the domain and integrated over the domain).
- netcdf output: profiles, sheets, curtains and 3D datablocks (depending on the hydrodynamic driver used).
V. Further information in the World-Wide-Web
VI. Additional remarks
Last review of this document by: Thu Mar 22 07:33:45 2001
Status of the document: Barbara Robson
last modified by
Tobias Gabele Wed Aug 21 21:44:40 CEST 2002