Hi all, Many thanks for the responses and feedback! :) Here a few comments:
- The aim would be to collect information on historic floods and community knowledge of hazard exposure. I work for the Red Cross Climate Centre on hazard assessments in typically data scarce areas (e.g. East Sudan). While in many western countries most flood areas have high-quality flood maps derived from scientific flood models, in those areas we lack this information. There are of course global flood models, but they lack verification and validation on a local level in many areas I am looking into. Especially there, being able to capture information of historic, true flood extents and community knowledge is crucial to fill those data gaps and improve disaster risk reduction efforts. - I reviewed existing tags and tag info, but I thought it lacked some uniformity. While with boundary=hazard and the added value there already exist approved natural hazard tags which I find make more sense to add in here. - The OpenHazrdMap was set up as Wiki Page but wasn`t followed through and no voting or approval for suggested tags was carried out. Please let me know what you think, and whether you would approve to adding the flood value 'flood' as value to the key 'hazard' (to be used in combination with the tag boundary=hazard). All the best and many thanks, Cornelia On Fri, Jun 16, 2023 at 9:13 AM Jez Nicholson <jez.nichol...@gmail.com> wrote: > 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 >
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