REGIONAL DEVELOPMENT SUITABILITY MODEL

Modeling Approach

The concept behind the model was straightforward: Create a series of digital data layers representing critical factors influencing land use change and then overlay those layers using Geographic Information Systems (GIS) technology. The outcome would be a map or series of maps showing where growth is most suitable in the CMRPC's 960 square mile region.

Crucial to understanding the model's results is the difference between suitability and predictive ability. Throughout presentation of the model it was emphasized that the results images depict areas better suited for development. These images do not necessarily show areas most likely to develop. Local factors, among them, taxes, land availability, community attitudes toward development, would likely assert a significant influence on which lands actually developed. In turn those lands may or may not coincide with those identified in the model's results. The results really show, from a theoretical perspective, where growth should go in an ideal world.

A huge number of technical and methodological hurdles had to be surmounted to produce the final model results. These ranged from how to convert data from one format to another to how to realistically represent the influence the intersection of two roads has on location decisions.

This report will not go into detail about the methodologies used to create each of the factor layers nor the numerous individual decisions made to generate the final results; this would simply be too long and technically complex. Suffice to say that model layers were developed in house in a sometime arduous process that involved either 1) modifying data collected from outside sources (principally MassGIS) or; 2) digitizing data in-house. The layers used in the model were chosen after research in the academic literature, discussions with experts in the field of GIS and land use planning and input from the public as discussed above.