Habitat Modeling

The goal of this assignment was to create a habitat model of primary and secondary habitats for the Mexican Spotted Owl in southeastern Utah. For their primary habitat, Spotted Owls require a landcover type of Pinon-Juniper Woodland, a concavity of -3.47 or greater, an aspect of North, Northwest, or Northeast, and steep canyons with a slope of 40° or greater. For their secondary habitat, the owls require the same landcover type and concavity, but slope and aspect are more flexible.

Reclassify and Raster Calculator

For this lab, this tool was used to edit the rasters into a binary (true/false) input for each of the criteria. For example, if slope is greater than 40°, it is represented with a 1. If the slope is less than 40°, it is represented with a zero. In order to differentiate between criteria, orders of magnitude were used to represent each. Landcover is represented with a value of 10,000, concavity represented with a value of 1,000, aspect represented with a value of 100, and slope represented with a value of 1. After reclassifying all of the elements, the Raster Calculator tool was used to add all of the criteria together. In this case, the primary habitat was represented with a value of 11,101. A secondary habitat with a suitable slope was represented by a value of 11,001, and a secondary habitat with a suitable aspect was represented with a value of 11,100.

Extract Raster by Attributes

In order to create three separate maps with primary and secondary habitats only, I used the Extract Raster by Attributes tool. Using this tool, cells that meet a specified attribute query can be extracted to a new output raster. 

Raster to Polygon and Total Area Calculations

In order to find the total habitat area, the raster must first be converted to a polygon. Then, a field is added to the attribute table and geometry is calculated to find the area of each polygon. Once the area has been calculated, the sum for all of the values is located in the chart properties. I repeated the process for the study area polygon to get it's total area, and divided the primary habitat area by the total area to get the percentage of the study area covered by the primary habitat.