Workshop C: Finding Yellow Birch
In this lab we'll explore how to manipulate boolean rasters to perform basic overlay operations, as well as explore terrain mapping. After we get comfortable with digital elevation models (DEMs) and boolean rasters, we'll create "ordinal" rasters that score the landscape for how likely it is suitable habitat for yellow birch.
Here is our workflow:
Download DEM and landcover rasters from VCGI, or download all data here.
Create subjective ordinal rasters that "score" habitats.
Combine scored rasters to create an overall suitability.
Make a map that shows the best places to look for Birch.
Here we'll take our newfound DEM experience and try it in a different region. Where are the best places to find Yellow Birch in Vermont?
In this video we take continuous rasters (DEM and aspect) and classify ranges into ordinal values. Our aim is to create a habitat -suitability- index based on subjective criteria.
After classifying the landcover raster, we combine all three into one -overall- suitability given these three parameters. This method is called a -multiple criteria evaluation-.
This crash course may be easier watched than followed. Cartography is a very circuitous practice and there will be time in the future to focus on that. For now it is important to see how the analysis goes from raw data to something more polished. Perhaps just follow along to the best of your abilities and then experiment on your own.