1. General Model Information

Name: The Conservation Area Landscape Model (CALM)

Acronym: CALM

Main medium: terrestrial air aquatic
Main subject: biogeochemistry
Organization level: ecosystem, landscape
Type of model: not specified
Main application:
Keywords: landscape, spacial modelling, ecosystem, environment, parallel processing, STELLA simulation modelling, wetlands, water management, canals, levees, Everglades, Florida, SME


Robert Costanza,
Maryland International Institute for Ecological Economics
Carl Fitz,
South Florida Water Management District
Tom Maxwell,
Maryland International Institute for Ecological Ecomomics
Fred Sklar, (fred.sklar@sfwmd.gov)
South Florida Water Management District



The natural area of the Everglades is faced with the problem of an altered landscape due to large-scale water management (canals and levees) that has redirected water that historically flowed through the Everglades. These canals and levees impound and redirect water, resulting in a mosaic of natural wetlands, urban and agricultural land use. The object of the CALM and ELM projects is to develop a simulation modeling tool for evaluation of scenarios of water management. The Conservation Area Landscape Model (CALM) is a spatial ecological model of WCA2A at a higher spatial resolution than the Everglades Landscape Model (ELM) (1,734 0.25km2 cells vs 10,264 1.0 km2 ELM cells). The CALM contains a unit model, The General Ecosystem Model (GEM) identical to the ELM and has the same forcing functions where appropriate, e.g., structure inflows and one station of precipitation. Due to the significantly higher quality/quantity of data for WCA2A (and faster runtime), the CALM is being used as the test platform for debugging and calibrating much of the ecological (including hydrologic) components of the larger ELM. Whereas the CALM has a relatively simple canal configuration, the ELM contains the complex canal/levee network, with structure flows that are determined by either historical data or management rules (all database driven instead of hard coded).

Some Sensitivity Results

For the bulk of the analyses of ecological sensitivity at the spatially explicit scale, we used the CALM. For this document, we include a couple of examples of the CALM response to varying some of the ecological parameters.

The best parameter estimates were used in the nominal runs, and the state variable responses at the end of one-year model runs using low and high parameter values were compared to those nominal runs. These comparisons are presented in a series of landscape snapshots for some of the important landscape driver variables. The snapshots below show the change in the state variable relative to the nominal run, with the left column of snapshots representing the change in the state variable when the parameter was decreased, and the right side representative of changes due to increases in the parameter. Whereas white represents no change between the nominal and the altered-parameter runs, a blue pixel indicates that the nominal run had lower values (in percent) of the state variable compared to the run with the parameter change, and a red pixel indicates that the state variable was higher in the nominal run compared to that of the run with the changed parameter.

Author of the abstract:

Robert Costanza
Maryland International Institute for Ecological Economics

II. Technical Information

II.1 Executables:

Operating System(s): scanner, digitizer, GIS data bases, computation system (Macintosh), STELLA, Spacial Modeling Package (SMP).

II.2 Source-code:

Programming Language(s): FORTRAN 77

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

V. Further information in the World-Wide-Web

VI. Additional remarks

In the CALM model SME version 1 has been used to develop a spacially explicit, dynamic simulation model of the ecosystem(s) within a particular landscape.
Another example of such a model: SME
Robert Costanza
Maryland International Institute for Ecological Economics
Last review of this document by: T. Gabele: Tue Oct 7 1997
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:40 CEST 2002

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