I have a layer of contiguous (pink) polygons (UK Parliamentary constitutencies) and a separate layer containing (blue) polygons representing protected nature areas (Natura 2000 areas):
Each constituency consists of a single polygon. Each Natura 2000 area can consist of one or more polygons.
For each constituency I need a combined total for the number of Natura 2000 areas that are:
- contained in
- touched by
I've added both as vector layers in QGIS and tried using Spatial Query and Topology Checker plugins and Geoprocessing tools (Clip, Intersect). But I don't really know what I'm doing. Although I was able to select constituencies where there is an intersect I couldn't see the number of intersects per constituency and this didn't solve my need to include touching and contained polygons in the totals.
And just to be clear about Natura 2000 areas consisting of one or more polygons. In this screenshot (contained in a box) is an example of a single Natura 2000 site consisting of multiple polygons. Because all of these polygons are contained in a single constituency we'd only want to count them once as a single Natura 2000 area. But if they were spread across the boundaries of constituencies we'd count them for each constituency any part of them touched/overlapped/was contained by. In the same way we'd count the single polygon Natura 2000 site that overlaps two constituencies (circled) twice - once for each constituency it covers.
(For background, I'm campaigning to protect Natura 2000 areas and my aim is to develop a target list of UK Members of Parliament prioritised by those who have the highest number of these areas in their constituency.