Tracking Creatures of Bavarian Folklore Using a Least-Cost Path Model

Table of Contents

  1. Tracking Creatures of Bavarian Folklore Using a Least-Cost Path Model
  2. Setting up Your Workspace
  3. Preparing the Data
  4. Skill Drill: Geocoding an Address and Creating a CSV Table to Import As XY Data
  5. Skill Drill: Defining the Study Area
  6. Skill Drill: Acquire Elevation Data from the USGS National Map Viewer
  7. Skill Drill: Acquire Land Cover Data from the USGS National Map Viewer
  8. Skill Drill: Acquire Hydrography Data from the USGS National Map Viewer
  9. Changing Global Environment Settings for Raster Processing
  10. Creating Cost Surface Models Using a Relative Cost Scale
  11. Creating a Remap Table to Reclassify Elevation
  12. Skill Drill: Creating a Remap Table to Reclassify Slope
  13. Skill Drill: Creating a Remap Table to Reclassify Tree Canopy Density
  14. Converting the Hydrography Features to Cost Surface Models
  15. Creating a Total Cost Surface Model
  16. Creating a Cost-Distance Surface Model
  17. Creating a Migration Corridor
  18. Determining the Least-Cost Path
  19. Skill Drill: Creating a Map of the Results

Changing Global Environment Settings for Raster Processing

Change the global environment settings so that the raster processing you will perform in later steps will be constrained to a specific geographic extent. In this instance, you want all raster processing to match the extent of the clipped digital elevation model. Also, the clipped digital elevation model also has the finer resolution than the tree canopy layer. You will change the environment settings in ArcMap so that any output will also match the resolution of the clipped digital elevation model. In ArcMap, select Geoprocessing from the main menu, then select Environments.

An image of the Geoprocessing menu
The Environments settings under the Geoprocessing menu are global settings. Any changes you make here will affect most of the tools you will use later on.

This step will open up the Environment Settings window. Here you will define the Processing Extent globally. Any changes you make here will affect the processing extent for tools you will use later on. Under Processing Extent, use the drop-down menu to select your clipped digital elevation model. Under Snap Raster, you should also select your clipped digital elevation model. Under Raster Analysis set the Cell Size setting to Minimum of Inputs. By default, the coarsest resolution of any input layers is used as the output for raster processing. By changing this setting, the smallest cell size of any input rasters will be used to define the output. For example, the clipped DEM has a cell size of 10 meters and the tree canopy layer has a cell size of 30 meters. If you multiply these two raster layers together using the Raster Calculator tool, the default output would have a 30-meter resolution. After changing the Cell Size setting to Minimum of Inputs, the output would use the 10-meter resolution of the DEM instead of the 30-meter resolution of the tree canopy. Also, since you changed the processing extent and the Snap Raster to match the DEM, the output would also match the size and cell alignment of the DEM.

An image of the environment settings window
In this example, I named the file for the clipped digital elevation model DEM.img.