On Thursday 15 January 2015, johnw wrote: > > A wadi is a place where flash floods occur. It is not an intermittent > river - it isn’t really seasonally wet, and doesn’t provide any real > expectation that water will be present (except deep underground) - > because they are located in places where rain itself is unexpected > for most of the year.
Well - that would be a useful concept of a wadi but it has two problems: * current use of the tag is very different from that, you can see that quite well when you look at the taginfo map: https://taginfo.openstreetmap.org/tags/waterway=wadi#map the uses in Europe for example are probably almost always seasonal. * sporadic waterflow is very difficult to determine for the mapper. This is especially true for northern Africa where climate got a lot drier in the last few thousand years and as a result there are many permanently dry valleys that still look like being formed by waterflow but that have not seen significant waterflow in the last hundred years. My suggestion would probably be to stop rendering waterway=wadi in a way implying waterflow, encourage mappers to use intermittent/seasonal where this is known and reserve waterway=wadi - despite the then misleading key - for valleys where waterflow is unknown. -- Christoph Hormann http://www.imagico.de/ _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
