Hi Frank, - the quick answer is yes - the long answer is also yes but with explanations ...
The shape/area covered by a water body depends on changes in water level - usually related to latest precipitation, snow melt or tide -. This means that you ends up with thousands of modifications each time you update water bodies using the actual water limit. This was the case until 2002. We then decided to use the concept of high/low water levels instead. The Permanency attribute indicates if the feature represents a low water level (1-permanent) or an area between the low and high water level (2-Intermittent). In this case (2), we don't modify anymore a feature based on the actual water limit, as long the water limits is within the Intermittent feature. You wrote "I'm not really sure if there are such lakes in the prairies". Well, on the contrary! Most of the water bodies are Intermittent there. I hope I made it clearer. Concerning Osm, there is no water level definition for the moment but there is a proposed feature that match perfectly (*)! http://wiki.openstreetmap.org/wiki/Proposed_features/Water_cover If accepted, there will be a perfect - and easy - match between Canvec and Osm water body definition. Can this proposed feature be moved forward? Should we use this feature even if not accepted yet? Meanwhile, it can be described more accuratly than we do using multiple tags as proposed by Richard but it will need image interpretation. Cheers, Daniel (*) I wished I have done the proposition myself! -----Original Message----- From: Frank Steggink [mailto:stegg...@steggink.org] Sent: 15 février 2010 21:03 To: Bégin, Daniel Cc: Richard Weait; Talk-CA OpenStreetMap Subject: Re: [Talk-ca] canvec mep feature 1150012 10- Coastal water - (Eau côtière) = Ocean - ( Océan ) Hi Daniel, Is the permanency attribute only used for tidal influences, or does it indicate intermittent rivers / lakes as well? I'm not really sure if there are such lakes in the prairies, so I want to make sure that they aren't imported incorrectly. Since you describe that the land use is different for tidal areas, is there a way to distinguish among them, or should this information be provided by the specification code? Frank Bégin wrote: > Hi Richard, > > It's the best description we could find in the wiki! > > About water, you must alway look at the Permanency attribute (Canvec and > GeoBase). It defines if the area is always under water (plane blue on NRCan > maps) or the area is rather a feature associated with water movement > (textured blue) like beach, tidal flat, wetland, rocks in water. > > Cheers, > > Daniel > > -----Original Message----- > From: talk-ca-boun...@openstreetmap.org > [mailto:talk-ca-boun...@openstreetmap.org] On Behalf Of Richard Weait > Sent: 15 février 2010 08:33 > To: Talk-CA OpenStreetMap > Subject: Re: [Talk-ca]canvec mep feature 1150012 10- Coastal water - > (Eau côtière) = Ocean - ( Océan ) > > On Mon, Feb 15, 2010 at 8:03 AM, <stegg...@steggink.org> wrote: > > >> By the way, there are (at least) two different water areas at the >> coast. I believe one of them includes tidal flats / mudflats. Should >> they be imported differently? If so, how? I looked at the Map >> features page on the wiki a while back, but couldn't find something >> which was really appropriate. >> > > Perhaps? > http://wiki.openstreetmap.org/wiki/Wetland > natural=wetland; wetland=tidalflat; tidal=yes > > _______________________________________________ > Talk-ca mailing list > Talk-ca@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-ca > > _______________________________________________ > Talk-ca mailing list > Talk-ca@openstreetmap.org > http://lists.openstreetmap.org/listinfo/talk-ca > > _______________________________________________ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
