I have a DEM file that I created a slope map of using
gdaldem slope. This works fine and if I view and colorize it, I can now see how steep a hill is but now I'd love to create a shapefile out of that. So I'd like to have polygons with increments of let's say 5% for each level of steepness.
I though I would go ahead and create
gdal_contour of that slope-DEM file and using the
-p option to create polygons rather than lines, but the problem is, that this takes FOREVER. Even a small sample file of a few square-kilometers (and about 20MB in file-size) is taking a couple of hours.
My command was:
gdal_contour -i 5 -amin 30 -p input.tif output.shp So increments of 5% starting at 30% and polygons.
How can I approach my problem?