Lab 1 - Suitability Analysis

This week we jumped right into Suitability Analysis, specifically Boolean and weighted overlays. After a brief lecture about suitability modeling, I began the three part lab assignment. First was creating a vector-based Boolean suitability model, which exposed me to a host of new tools, including the Slope tool, Reclassify tool, and Convert Raster to Polygons tool. After reclassification of land cover, slopes, and soils, plus buffers for roads and streams, I combined the feature classes with the Union tool, then used an SQL query to obtain final results showing suitable mountain lion habitat in the study area.

Part two was again working with Boolean suitability values, but this time for raster files. Some earlier layers could be reused, although instead of buffers, I used the Euclidean Distance tool to create rasters for suitable distances from streams and roads. To combine all the layers I used the Raster Calculator, a tool that can do numerous types of math algebra to produce desired results, in this case a combination of raster layers showing cells that meet all criteria, and how many cells meet each criteria, for suitable mountain lion habitat in the study area.

Our final part of the lab was to use weighted overlay to rate suitable locations for housing development. Using land cover, slope, soil, roads, and streams, reclassified with suitability ratings of 1-5, I combined all final results using the Weighted Overlay tool. This tool multiplies the interval suitability ratings (1-5) by a weighted suitability value I have assigned for each layer. The weighted values are decimals (representing a percentage), so the final output results are rounded up to produce integers for the final output raster. The first weighted overlay used 20% equally for all layers, while the second weighted overlay analysis used unequal influence with higher importance on lower slopes and less importance on distance from streams and roads. The map compares the two different weighted analyses and highlights the impact that weighted value can have on output and potential decision making.

I enjoyed learning all the new tools, and paired with our online discussion assignment reviewing the strengths and weakness of suitability analysis, I feel I have a good start to understanding how to use these modeling methods in the future.

Map comparing equal and unequal weighting of layers to determine suitable land for housing development.