The second part of our final module in Applications covered least cost path and corridor analysis using cost surfaces. We worked with two scenarios. For the first scenario we analyzed slope, river crossings and river proximity to determine the best single possible location for a new pipeline within a given study area. We then took this information a step further and presented a corridor analysis. To do this we reclassified our features with their cost factor and utilized the Cost Distance and Cost Path tools.
Image 1
First we assessed for slope alone. As you can see this first image contains 4 water crossings.
Image 2
After adding the addition cost value of the river crossing the adjusted pathway only contained two water crossings (yellow). However, we further adding a 3 raster feature layer to the cost analysis for river proximity. This gave us the final path in image 2 (red).
Image 3
Finally, we used the corridor tool to get a corridor analysis of the data. Image 3 depicts a copy of the final least cost analysis overlaying the corridor analysis
After establishing the basics of performing a corridor analysis we were tasked with determining the most likely corridor for black bear migration between two protected areas of Coronado National Forest. We evaluated suitability based on slope, proximity to roads, and landcover surveys.
After giving suitability ratings to each of my variables, I ran a weighted overlay to establish the importance of each variable for the cost surface. I ran my cost surface in the cost distance tool with each protected area to create two rasters for the corridor output. When running the corridor analysis I got a very widespread result that I wanted to narrow down. To do this I created an empty polygon feature class for my proposed corridor and drew a polygon around the most suitable of the corridors. I then clipped my raster to my proposed corridor.
Here is my final map:
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