Site Suitability Analysis
Suitability Analysis and Weighted Overlay
The increasing interaction between visitors and the black bear population at the Great Smoky Mountains National Park is of concern to Biologists, who want to find a suitable place within the National Park to relocate bears away from roads and trails and closer to streams to minimize their interaction with park visitors. The biologists have provided a list of five factors to determine suitable land for bear habitats. The factors are ranked from 1 (favorable) to 3 (most favorable) and provides a range of values for road, streams, and trails that are most suitable to relocate black bear population. The criteria also include vegetation and slope also ranked from least favorable to most favorable.
To determine the most suitable site to relocate black bear population, I will utilize Model Builder in ArcGIS 10.6.1 to conduct slope, feature to raster, Euclidean distance, reclassify, and weighted overlay analyses. The five data layers are roads, streams, trails, vegetation, and elevation.
First, I created a toolbox and generated an empty model. The raster file contained elevation of the National Park. I added all five layers to Model Builder. I used elevation raster as input and used the Slope tool to derive the raster layer. To create a raster data set, the vegetation polygon layer was used as input in the Feature to Raster tool. The trails, roads, and streams layers (polylines) were used as inputs using the Euclidean distance tool to convert them into raster layers. The cell size of the output raster data set was kept at 30 m.
Next, I reclassified all raster files using the Reclassify tool. Based on the criteria listed in table 1, old values were reclassified as 1 (least favorable), 2 (favorable), or 3 (most favorable). Lastly, I used the Weighted Overlay tool and set the evaluation scale to “1 to 3 by 1” and assigned equal weights, 20%, to all five layers.
Application & Reflection
Problem description: A medical practice wants to build its clinic in Charlotte, NC. They want to do suitability analysis before purchasing the land for construction. The clinic will cater mostly to middle-income residents. The clinic must be close to roads, on a bus line for easy access, relatively flat surface, and in a low crime area.
Data needed: Land/parcel DEM data are available for download from Open Mapping website of the Mecklenburg County. I also have the County, line, roads and streams shapefiles.
Analysis procedure: I will add layers to Model Builder, convert layers to raster data sets, reclassify, and finally conduct weighted overlay analysis. I will reclassify rasters based on predefined favorability criteria. For example, surface elevation will get 40% weight, closeness to the main road will get 10% weight, on a bus line for easy access will get 20% weight, and low crime area will receive 30% weight.