Module 6: Part 2- Black Bear Potential Movement Suitability Raster Analysis

In the second part of Module 6, the goal was to determine the area(s) that have the highest potential for black bears to cross between two, separate areas of Coronado National Park. The potential movement of the black bears was assumed to meet the criteria below: 

1. Far from roads (assuming black bears avoid the roads for safer routes and less noise disturbance)
2. Mid-elevations (where there is likely more food sources and easier to traverse)
3. Forested areas (assuming barren and developed areas are the least suitable)

Data required to complete the analysis included the location of the two parts of Coronado National Forest (polygons), elevation DEM, land cover data, and roads (polylines). The land cover and elevation rasters were reclassified using the Reclassify tool and a new attribute for the class rating was added. Rating scale went from 1-10 with 10 being the most suitable. Forested areas and elevations between 1200-2000m received the highest rating. Next, the Euclidean distance tool was used to determine the road distance values and the output raster was then reclassified using the Reclassify tool and each class category was rated on a scale from 1-10. All three rasters  were then inputted into the Weighted Output tool, with land cover weighed the highest importance, at 60%, and elevation and roads at 20%. The output was then inverted, based on the assumption that the areas with the highest cost to traverse would typically be avoided by the black bears. Then, the Cost Distance tool was used on the first part of the park boundary polygon and the weighted overlay output raster. This calculated the cost or effort to reach that area. This was repeated on the second part of the park boundary. After two cost distance rasters were created, the Corridor tool was used on both park boundaries to determine the least-cost path from one section of the park to the other. This raster was then reclassified to two categories, all values below 25000 and all values greater than 25000. The values below 25000 are then classified as the corridor in the final raster output. The corridor area where black bears were determined to have the highest potential of movement from one park section to the other is shown in the map below: 

In this map, the corridor is shown are a red, hatched area and the two park sections are show with a black dashed boundary. The corridor raster was symbolized with a color ramp ranging from red (low potential movement) to high (green). The corridor shows areas that would potentially be avoided, such as the large area to the north near Agua Linda, most likely due to the influence of land cover.