Given the current discussion, I wonder if roads that are usually flooded during heavy rainfall should be also be tagged as waterway=river/stream and intermittent=yes. ;-)
On Fri, Jan 16, 2015 at 7:27 AM, John F. Eldredge <j...@jfeldredge.com> wrote: > I would recommend expanding the definition of "intermittent streams" to > include not only streams that have a regular, seasonal water flow but also > streams in desert areas that exist only when a rare storm comes along. The > topography is the same, the tendency of water to run downhill is the same, > only the frequency of rainfall is different. > > -- > John F. Eldredge -- j...@jfeldredge.com > "Darkness cannot drive out darkness; only light can do that. Hate cannot > drive out hate; only love can do that." -- Martin Luther King, Jr. > > > > > On January 15, 2015 3:13:38 AM Christoph Hormann <chris_horm...@gmx.de> > wrote: > > 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 >> > > > > _______________________________________________ > Tagging mailing list > Tagging@openstreetmap.org > https://lists.openstreetmap.org/listinfo/tagging >
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