Thursday, August 03, 2006

Repast Models of the Week:The SLUDGE and SluGIS models

The SLUDGE model (Simulated Land Use Dependent on Edge Effect Externalities) was developed by Dawn Parker. The combines a simple cellular automaton and agent-based model which was designed to study the joint influence of distance-dependent spatial externalities and transportation costs on patterns of land use. Further information on her work can be found at discussed in the following papers:
Parker, D. C. 1999. "Landscape Outcomes in a Model of Edge-Effect Externalities: A Computational Economics Approach", Santa Fe, NM: Santa Fe Institute Publication 99-07-051 E.
Parker and Meretsky, 2004, "Measuring Pattern Outcomes in an Agent-Based Model of Edge-Effect Externalities Using Spatial Metrics"; Agriculture, Ecosystems, and Environment 101:233-250.
A Repast model of SLUDGE has also been programmed by Robert Najlis. The source code for the original model can be downloaded from here. Alternatively if you viewing this post on a computer using windows, you can run the model directly by clicking here.
Robert Najlis has also developed a model called SluGIS which is a closely-related model of of SLUDGE. With the major distinction as it is a move away from the cellular space used in the previous model. SluGIS runs on a vector landscape. Robert Najlis has used Repast GIS functionally (and produced the same model both ESRIs and OpenMap interfaces of Repast).
A modified OpenMap version can be run by downloading the following and unzipping the following Shapefile package (download Shapefiles) and storing it to disk. Then by running the model by clicking here and choosing the shapefile you just saved to disk.
The original java files for the OpenMap and ESRI SluGIS models can be found here. A modified ESRI version which was created by Michael Leamy can be downloaded from here. All that needs to be done is to change the path names for the .shp file, the .gal file, and the refresh call. Look for this in SluGISEsri.java.
For more information on Repast GIS see the Repast website “How to use GIS data with Repast”.

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