I have OSM road network data in QGIS along with a shapefile showing the possible extent of a flood.
My question is: is it possible to exclude all of the roads that are in the flood zone (so as to pretend that they are flooded/impassable) and generate a road network that can then be used for routing?
My initial thought was to use the clip function but it simply clips the road network shapefile to the same overall shape as the flood shapefile, not just the sections that would actually be flooded.
This screenshot may help explain a little more…
Best Answer
The Difference Tool should do what you want as @Baltok has suggested.
Just set the streets layer as the input layer and the flood layer as the difference layer.
This should result in a new streets layer but with the flooded area removed. You might want to check this tutorial for more details.