Module 1 - Suitability Analysis & Modeling

Suitability Analysis (also referred to as multi-criteria decision-making, multi-criteria evaluation, site selection, and /or weighted linear combinations) is a type of analysis used in geographic information science (GIS) that determines the most suitable locations for something based on a set of criteria.

If you think about it, suitability analysis is used all the time, and for very important issues! Some major examples include in 1. Land Assessment (Where to construct the next Publix? Where to build a new landfill? Where to place the next big theme park?), 2. Habitats (predicting where species will migrate to next, or where they might thrive best; and in establishing conservation and/or restoration efforts), 3. Archaeology (in predicting the probability of historic settlement patterns), and 4. Tourism (in determining lucrative potential). (Zandbergen)

There are various methods of suitability modeling. But in this week's lecture and lab assignment we concentrated in 2 basic variations: Boolean and Scores/Ratings. Specifically, we modeled Boolean suitability in both vector and raster, and for our final map deliverable (as shown in the attachment above) we modeled a suitability based on a weighted overlay analysis of both equal and unequal ratings.

Going into more detail, the suitability model depicted in my map rates suitable locations for a housing development project based on landcover, soils, slopes, distance to streams, and distance to roads criteria. Essentially, all layers were Reclassified using the Spatial Analyst Toolbox in ArcGIS and assigned new values of suitability ratings. For the slopes file, I had to first use the Slope tool to convert the provided DEM file into a raster format before Reclassifying it. For the linear files (streams and roads), I used the Euclidean Distance tool to create a raster before Reclassifying it as well. Once all suitability layers were prepared, we used the Weighted Overlay tool to combine all of the rasters together; the first of which included an equal weigh influence of 20%, and the second which depicts an unequal weigh influence based on factors in accordance to its importance.

References:

Zandbergen, P. A. Suitability Modeling (PowerPoint Slides).