I have a map I generated that roughly estimates timber industry land ownership (designated by the green on the map) in the counties surrounding the Salish Sea in the US state of Washington:
I want to remove parcels below a certain area threshold (e.g "only show parcels larger than 20 acres"). But the problem with this is that many of the larger timber tracts are broken up into a bunch of smaller adjacent real property parcels. Thus, a timber company might have a contiguous 20 acre parcel that is broken up into four 5-acre parcels, and a simple "features where area > 20 acres" search would miss this parcel.
So what I am trying to figure out how to do is show any parcels that are either (a) larger than 20 acres or (b) part of a connected cluster/group of parcels that collectively cover more than 20 acres.
For example, zooming in on part of the above map:
I want to filter out any parcels that are smaller than the reference parcel, unless they are part of a larger cluster of adjacent/connected parcels (such as the one I labeled with the blue arrows in the image), and generate a new layer with these smaller, disconnected parcels removed.
Is there an easy way to do this through QGIS?
If not, does anyone have any ideas for Python libraries or command-line utilities I could use to achieve this?