I’ve run into a bit of a pickle. I’m attempting to isolate “islands” within a large OSM-derived network. I’m interested in highlighting areas where the network cannot connect to. This of course includes actual, physical islands, but it also includes the interest of my research, which is sections of the network that haven’t been properly created and are not connected to the rest of the network.
I’ve been attempting to do this using QGIS’s QNEAT3 plugin. I’ve been creating interpolations of network costs from a point, and attempting to use that to highlight sections that are not being included in the network. This isn't working however, as network cost calculations include areas from the network, and don’t really highlight segments that are completely disconnected from the network. See the following screenshot of a section of a network connected, and the same section cut out to be a “network island.” The contour lines represent the cost of the network, and as you can see, the island section is not included in my network - which is exactly what I want!
What would the easiest way of highlighting sections of a network that do not connect to the rest of the network be? Is there a way of doing it using QNEAT3?