I've merged together a polygonized raster layer of a certain elevation grade (>25%) and a wetlands buffer. I can't seem to find a good solution to the problem at hand, however. Ultimately I'd like to run a symmetrical difference tool on the merged layer (mentioned in the former) and a parcel layer to find suitable land to build on.
So far I've tried running v.clean (snap, rmdupl, and bpol, all to no avail). Manually cleaning lines is totally out of the question. Dissolving takes a ridiculous amount of time and computing power. Any better alternatives?
Here's what my data looks like: