Ideally, the best sites for bear relocation are more than one mile away from roads and trails, under a half mile to water, on relatively flat terrain with certain types of vegetation. Using datasets of these five requirements provided by park biologists, I used ArcMap to examine polygon data of vegetation types, line data of streams, trails and roads and a raster image of elevation data. Using Model Builder, I created a model to convert these data sets to raster data using the Feature to Raster tool, Calculate Euclidean Distance tool and the Calculate Slope tool respectively. The Reclassify tool enabled me to classify values into three categories of favorability. These datasets, on equal scales of 1 to 3, were equally weighed in the Weighted Overlay tool producing an image showing the least, moderate and most favorable habitats.
I started by adding the 5 data layers to Model builder and the tools to complete the analysis. In all tools, where available, selections were made to change missing values to “NoData” and cell size output was set to 30 meters (m) to correspond to the cell size of the elevation raster.
I used the Streams shapefile as the input data to the Calculate Euclidean Distance Tool. The resulting greyscale raster “Distance to Streams” had values up to 6,330m. This image was used as the input to the Reclassify Tool where three new classifications were created. The most favorable condition, close proximity to a stream, was given a new value of 3 and assigned values of 0 to 804.67m (0.5 mile). The new value of 2 was set to values from 804.67m to 1,609.34m (1 mile) and new value 1 was all pixels with a value over 1,609.34m.
Distances to roads and trails were set up in a similar manner with the main difference being in the classification, where greater distance locations were more desirable. For each layer, the Calculate Euclidean Distance tool was used, and raster images generated. Each of these served as the input into their own Reclassify tool. For both layers, new classes 1 to 3 were created for areas up to 0.5 miles, 0.5 to 1 mile and greater than one mile respectively.
I used the Elevation Raster as input for the Calculate Slope tool with the output results in degrees on a flat plane. This tool produced a new raster “Slopes from Elevation” which I then set as input for the Reclassify tool. The most desirable trait for bear habitat is little to no slope. In the three classifications set here, the value of 3 consisted of slopes of 0°- 30°, class 2 was set for 30°- 60° and class 1 was set to 60°- 90°.
For the fifth dataset, the vegetation types shapefile, I converted the polygon data to a raster image using the Convert to Raster Layer tool. The conversion was based on the field “CLASSES”. The resulting gridded raster was comprised of fourteen classes of tree coverage. The Reclassify tool was added and each of the 14 classes set to a new class of 1 to 3. Only grape thickets fell into the most favorable category of three. Category 2 comprised cove hardwood, mixed mesic hardwood and northern hardwood. The remaining categories were less favorable/undesirable and assigned to category three.
The processes described here produced a 30m resolution three category gridded raster for each layer. I added the Weighted Overlay tool to the model to combine the five layers. Each layer was given a 20% influence in the final image which was produced using a 1 to 3 by 1 evaluation scale. The results show all areas that are most suitable for bear relocation.
In another project, I’m currently looking at real estate and identifying properties based on various traits for redevelopment.
Using housing data on renovations from the US Census Bureau, elevation data from the USGS, Wake County greenway & parks data and Sentinel2 imagery. Another source of data to be investigated are property tax reassessment changes to find homes that have significantly changed in value indicating a highly renovated property.
I can then identify properties that are on relatively level lots by using the calculate slope function. I would then use the sentinel 2 imagery infrared bands to classify the image into 5 groupings based on the percentage of the parcel covered by trees. Using the calculate distance tool would allow me to find properties near parks/greenway access points in .2-mile increments. The census data could be joined with parcel data to find homes that have not undergone significant renovation based upon their property tax value changes. I would reclassify these layers into a 5-point scale system to be combined in in a weighted overlay. The categories with heavier weight would be properties with minimal to no renovation and larger lot sizes while tree coverage and proximity to parks/greenways would have a lower weighting.