Noted.
I was [over]reacting to the section from OP about return periods. If this proposal is specifically about areas of historical flooding rather than areas deemed at risk of flooding then they *can* be observed on-the-ground. On Fri, 16 Jun 2023, 01:08 Andy Townsend, <ajt1...@gmail.com> wrote: > On 15/06/2023 20:47, Jez Nicholson wrote: > > Whilst it is a great idea to capture local knowledge about flooding, > especially where it is currently not available, I am concerned that this > doesn't have on-the-ground verification. > > I don't think that anyone has suggested that - at least not in this > thread? > > The original email said "The location and extent of these hazard areas is > often well known by local communities with knowledge of past events." > > When I talked about "what is currently flooded based on current measured > level and previous observations" I meant exactly that - recording that > when a river level at a known point reads X, land at Y (in the vicinity of > X) will also be flooded. > > > Flood risk areas are predictions generated via modelling software and it > depends on which software you use, and the quality of the input data. > > Indeed - the Environment Agency in the UK (and other agencies elsewhere) > make extensive use of this sort of model, but I suspect that mapping this > sort of thing goes bit beyond what can usefully done within OSM, though of > course it can be combined with OSM data by a data consumer to create "risk > maps". > > > The current hazardous areas get away with it by mapping areas marked out > by signage. Sure, the signs may have been placed following predictions, but > they are physically there to be seen. > > I suspect that this isn't true for all "boundary=hazard" in OSM at the > moment (picking one at random, the signage for > https://www.openstreetmap.org/way/500428513 and the wider > https://www.openstreetmap.org/relation/15680620 doesn't look especially > extensive - see > https://www.abc.net.au/radio/programs/australia-wide/australia-wide/13490888#:~:text=Wittenoom%20is%20the%20largest%20contaminated,site%20in%20Western%20Australia%27s%20Pilbara. > ) > > Best Regards, > > Andy > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging >
_______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
