A common geospatial workflow is to assign raster values to a coincident vector layer so that you can style or perform further analysis on the vector layer. This recipe will use this concept to illustrate the steepness of a road using color by mapping values to the road vector from a slope raster.
You will need to download a zipped directory from https://geospatialpython.googlecode.com/svn/road.zip and place the directory, named
road, in your
We'll start with a DEM and compute its slope. Then, we'll load a road vector layer and break it into interval lengths of 500 meters. Next, we'll load the layer and style it using green, yellow, and red values for each ...