On Mon, Aug 30, 2010 at 10:10 PM, John F. Eldredge <j...@jfeldredge.com> wrote: > -------Original Email------- > Subject :Re: [Tagging] Non Proposed Features > From :mailto:nerou...@gmail.com > Date :Mon Aug 30 20:44:53 America/Chicago 2010 > So how do you specify that (a) you mapped a waterway but don't know > the direction of flow, (b) it's a stagnant channel with no real flow, > or (c) it's an artificial drainage canal with flow changing based on > rainfall and opening or closing of gates?
> I would expect that case (c) would still have the water flowing downhill. > Even if you have a series of pumps, water in the sections between the pumps > will still flow downhill, not uphill. About the only time I would expect any > counterflow would be if water were to be added to a given section rapidly > enough that its surface level was temporarily higher than in the upstream > section, making that a downhill flow also. > Depends. The canals may be flat (or nearly so, such that one can't know which way is downhill) and managed by pumps. I believe this is common in "reclaimed" swamp lands. _______________________________________________ Tagging mailing list Tagging@openstreetmap.org http://lists.openstreetmap.org/listinfo/tagging
