The GSM was developed by the Maryland Office of Planning beginning in 1992 to project population growth and new development effects on land use/land cover nutrient pollution loads, and small streams under alternative land management strategies. To develop these estimates, the GSM uses population, household, and employment projections to estimate demand for residential and commercial development. Demand is then distributed to developable land, based on capacity under existing or alternative zoning, development regulations, and resource conservation mechanisms; and on information about development patterns and trends. Land use change to accommodate projected growth is then estimated as a function of management tools.
General Info
Developers:
Joe Tassone
Website:
www.mdp.state.md.us
Email:
JTassone@mdp.state.md.us
Strengths:
• Simulates land use change as a function of population, employment, land use management techniques, and market preferences.
• Can be customized to work a various levels of scale and detail.
• Can be used to extrapolate land use change for a much larger geographic area than that to which it was applied.
Outputs:
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Resources
User Input Requirements:
There is a great deal of flexibility regarding the data needed to run GSM. At a minimum, land use/land cover data and geo-referenced management areas are necessary to operate the model. An example of some of the data that have been incorporated into model applications are:
Time Commitment:
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Data Input Requirements:
ArcInfo Data needs: Land use; Soils, Watershed and county boundaries; Streams; Buffer zones; Environmentally sensitive areas; Zoning, growth, and land preservation boundaries; Sewer service boundaries; and Preserved land.
Database data: Population, household, and employment demographics.
Additional information is also required about the effects of management alternatives. For example, typical lot yields in an R-1 zoning district are 3 D.U. / acre, and there are not forest conservation requirements for subdivisions. This information can be derived from empirical data or values can be assumed based on potential ranges.
Equipment Needs:
The GSM is currently set up to run on a UNIX-based workstation or Windows NT. This could be modified to meet the needs of the user. Computer size and speed are a function of the database scale of resolution and the geographic extent of the study area. As it is currently being used, GSM requires a 500 MHz PC, 128 MB RAM, and 133 MHz bus speed. ArcInfo and a relational database (i.e., Paradox) software are also necessary to run GSM.
Limitations:
• GSM has to be customized for each application by a skilled programmer, depending on the scale, resolution, and data used to represent generalized needs.
• Cannot currently map land use change in vector format as output. The user must currently use geo-referenced spheres or buffer polygons, statistics, and graphs to look at the change.
Staff Requirements:
It is necessary that staff running GSM are comfortable with GIS and relational database software. GSM has not been packaged for less skilled users. The target users of the model are land use planners and managers, and others interested in land and water resource conservation. Calibration and use of model requires experience in land use management and modeling and programming in relational database applications (e.g., Paradox, Oracle).
Software Cost:
The GSM is public domain, but has not yet been adapted as an application that can be distributed to other users. Contact model developer for details.
Preview:
No preview copy is available. Contact model developer for additional information.
Maintenance Costs:
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