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EXAMINING REGIONAL LAND USE CHANGE: THE COMMUNITY GROWTH MODEL (CGM)
Citation:
Matheny, R W. EXAMINING REGIONAL LAND USE CHANGE: THE COMMUNITY GROWTH MODEL (CGM). Presented at Urban Regional Information Systems Public Participation GIS Conference, Portland, OR, July 20-22, 2003.
Impact/Purpose:
Provide regional-scale, spatially explicit information on the extent and distribution of both stressors and sensitive resources.
Develop and evaluate techniques to integrate information on exposure and effects so that relative risk can be assessed and management actions can be prioritized.
Predict consequences of potential environmental changes under alternative future scenarios.
Effectively communicate economic and quality of life trade-offs associated with alternative environmental policies.
Develop techniques to prioritize areas for ecological restoration.
Identify information gaps and recommend actions to improve monitoring and focus research.
There are two task objectives that reflect the work done by LCB in support of the ReVA Program objectives:
Provide information management, spatial analysis support, and data and information accessibility for the ReVA Program
Provide program management support, technology transfer, and outreach.
Description:
The U. S. Environmental Protection Agency's Regional Vulnerability Assessment
Program (ReV A) is designed to develop and demonstrate approaches to identify the ecosystems at the greatest risk from regional population growth and economic activity.
As part of this program, a cellular-based model is being developed to examine alternative land use patterns that could be influenced by policy changes. This presentation demonstrates various uses of the model to determine the conversion of forest and agricultural land uses to urban land uses under a variety of possible scenarios. The model itself examines possible policy changes in urban growth as reflected through the model spread equations, spontaneous growth equations and planned development assumptions. Concentration is placed on how the various model parameters can be modified by the decision-maker to analyze the implications of various land use policies. ReV A has used CGM to examine the population impacts in the Mid-Atlantic region and in the Neuse Rive Basin, and has completed baseline land use change projections by county for the entire Mid-Atlantic region.
Using a series of population projections the Community Growth Model produces a grid that integrates infrastructure and land use. It then calculates the area to be converted to three urban uses (low density residential, high density residential and commercial/industrial/transportation) from the population projections. Next it allocates new urban growth using three variations of a neighborhood function. CGM iterates for each projected year.