1. General Model Information

Name: Spacial Modeling of the Environment (SME) version 1.

Acronym: SME

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


Robert Costanza,
Maryland International Institute for Ecological Economics
Carl Fitz,
Maryland International Institute for Ecological Ecomomics
Tom Maxwell,
Maryland International Institute for Ecological Ecomomics
Fred Sklar,
South Florida Water Management District
Fax :



Our first attempt to address the conceptual and computational complexity barriers to spatial ecosystem model development resulted in an early prototype spatial modeling environment (SME, version 1, or SME.1) (Costanza & Maxwell, 1991; Maxwell, 1994; Maxwell & Costanza, 1994), which links an icon-based graphical modeling environment with automatic parallel code generators, allowing researchers to utilize advanced parallel computer architectures without having to invest unnecessary time in computer programming or learning new systems. The SME.1 is implemented as a set of commercially available tools that are linked through our prototype spatial modeling environment (SME). The SME.1 is shown diagrammatically in the figure below. In this version the unit model development and testing is done using STELLA* (Costanza, 1987), a commercially available dynamic simulation model development packages that is very easy to learn and use. The STELLA models represent local ecosystem site models. The site models can be linked through horizontal flows of nutrients, sediments, etc. (via the SME) to form spatial ecosystem models. STELLA generates an output file containing a set of finite difference equations that describe the model, which serves as input to the SME, which translates these equations into parallel C code customized for the targeted platform.

For original document and figure click here

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

The SME version 1. has been used to develop a spacially explicit, dynamic simulation model of the ecosystem(s) within a particular landscape. An example is the Everglades Landscape Model

ELM is contructed in a hierarchy using the ecological models, The General Ecosystem Model (GEM)and The Conservation Area Landscape Model(CALM).All these models may be accessed through ECOBAS.

Last review of this document by: 30.June 1997 -
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:49 CEST 2002

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