On 21/06/2025 14:55, Daniel Hatton via Talk-GB wrote:
It looks like, on OSM, we have parish boundaries in England imported as a numerical dataset from an OS OpenData product (they're tagged source:OS_OpenData_Boundary-Line). Unfortunately, the boundaries in this dataset appear to have been polygonized with a rather coarse granularity - about 15 metres. There are a few places in my area where this coarse granularity seriously obscures the fact that the actual parish boundary coincides with (and is quite likely legally defined by) a physical feature (mostly either the centreline of a watercourse or one bank of a watercourse). Compare, for example, the specification of the parish boundary we have at <https://www.openstreetmap.org/edit#map=18/52.116673/0.157049> with the finer representation of the parish boundary in the same area available from <https://maps.cambridgeshire.gov.uk/mycambs.aspx> or <https://www.ordnancesurvey.co.uk/election-maps/gb/>.
I have BoundaryLine loaded into QGIS, and it looks to me like the boundary mapping in this area is at best a simplified version of BoundaryLine. This suggests to me that something in the original import resulted in a loss of resolution. If that's the case, it might be best to try to reimport the BoundaryLine data more accurately.
-- Steve _______________________________________________ Talk-GB mailing list [email protected] https://lists.openstreetmap.org/listinfo/talk-gb
