For woods the problem is that there are 3 different levels of fire impact, and only the most severe is clearly visible in aerial imagery or from a distance - but this is also quite dangerous to survey in person.
) 1A "crown fire" (US English) burns the tallest trees which comprise the canopy or "crown" of the woodland. In the Northwest USA, this would be the tall Ponderosa pines, Douglas firs or similar very tall trees. This sort of fire leaves standing stags with no needles or leaves and the ground is usually scorched black - very obvious. 2) But most forest fires rarely reach the crown: most of the fire will be limited to the understorey (shrubs and immature trees). This is not always obvious on aerial imagery 3) Many areas of the fire will only burn the ground-level needles, leaves and herbs. This is not going to be apparent from the air. Areas of scrub can also have the last type of fire, though it is more common that the "crown" or "canopy" of the shrubland is burned, since it is closer to the ground and shrublands tend to have a very dry season. Dwarf shrub and heath and grassland areas will usually only have the last type and it will be quite obvious, but the herbs will regrown during the first rainy / growing season after the fire, so the burn is very transient: from just a month or two in wet tropical areas to perhaps a max of 9 months in arid areas. Similarly, scrubland areas (and burnt undergrowth) will have new growth of grasses and herbs within months and regrowth of woody shrubs within a couple of years at the most. So if it reasonable to map this? If you do map it, you had best be prepared to remap the area in 12 months and again after a couple of years, or the data will be quickly incorrect. I would also think it is pretty necessary to have the current natural vegetation mapped at the same time for surrounding areas, or the extent of the burned area will lack context. - Joseph Eisenberg On 1/27/20, Alan Mackie <[email protected]> wrote: > There are some tags documented on the Russian wiki page for key:wood [1] > that describe various types of damage to wooded areas, one of which is > wood:damage=burnt. I don't think it's been used much outside of Russia, but > it seems fairly reasonable for areas likely to regenerate. > > There have been other disaster tagging schemes that seem to be used on > occasion, but they always seem to be listed under a particular disaster's > wiki page rather than in some centralised location. > > It would be nice to get some more consistency here, but I think the problem > with this sort of tagging is that these tend to be the sort of thing that > should be locally surveyed and updating OSM generally isn't the priority > unless it is somehow part of a specific organisation's workflow. > > [1]: https://wiki.openstreetmap.org/wiki/RU:Key:wood > > On Sun, 26 Jan 2020 at 22:27, Warin <[email protected]> wrote: > >> Hi, >> >> >> I have come across a German mapper who has used 'landuse=brownfield' to >> map some recently burnt areas in Australia. >> >> I know this is not appropriate as it is not a land use, nor does it meet >> the OSM meaning of 'brownfield' in all situations. >> >> Note: this is done in areas, no matter if it is a farm field, recreation >> ground, residential areas etc. >> >> Tagging buildings and other OSM features is easy where they are wholly >> burnt using the life cycle tagging. >> >> >> >> Should this data be entered in OSM? >> >> Are flooded damaged areas mapped? Earthquake damaged areas? >> >> >> If entered how should they be tagged? >> >> The keys 'landuse', 'landcover', 'natural' don't look usable to me. >> >> It may not be possible to use a sub key as the burnt areas do not >> conform to the presently mapped features. >> >> If mapped then the tagging should be inclusive of other disasters >> (natural or not). >> >> >> Thoughts? >> >> >> >> _______________________________________________ >> Tagging mailing list >> [email protected] >> https://lists.openstreetmap.org/listinfo/tagging >> > _______________________________________________ Tagging mailing list [email protected] https://lists.openstreetmap.org/listinfo/tagging
