[Talk-ca] Canvec 10 and landcover issues

[Pierre Béland]

Harald, 

I dont know how you conclude that there is no wetlands around this area in Laval.  It is not sufficient to see houses around to conclude that there is no wetland. These are often wooded areas with water all over.  Google physical also shows a stream starting from this area.


The link below shows a comparison of this area with Google imagery.  Are you sure that there is no wetland in this area.

http://tools.geofabrik.de/mc/?mt0=mapnik&mt1=googlehybrid&lon=-73.91012&lat=45.69989&zoom=17


The link below shows an aera in Saint-Jean-sur-Richelieu were houses have been built for over 30 years. Look how many houses were flooded last year. Zoom in to see areas that were flooded.

http://pierzen.dev.openstreetmap.org/hot/openlayers/inondation-richelieu-2011.htm?zoom=16&lat=45.28568&lon=-73.24907&layers=B000TFFFF


My experience, as a volunteer for SOS-Richelieu, last year, showed me how that too often the municipalities have accepted that contractors build houses over wetlands. And this was often the case with Laval.

These imports are part of the process of building the OSM map. This import is a first step and local mappers will eventually validate and correct if necessary.

The same situation arises with imagery such as Bing when some buildings are built or others demolished.
What we need is to build a strong  community of mappers that will improve the map from the state it is presently.
 
Pierre 



>________________________________
> De : Harald Kliems <kliems at gmail.com>
>À : Talk-CA OpenStreetMap <Talk-ca at openstreetmap.org> 
>Envoyé le : Vendredi 19 octobre 2012 14h04
>Objet : [Talk-ca] Canvec 10 and landcover issues
> 
>Hi everyone,
>I've done some OSMInspector debugging of areas around Montreal and
>I've come across a number of newly imported natural=wetland areas,
>sourced from Canvec 10. that are clearly wrong. This, for example,
>http://www.openstreetmap.org/?lat=45.69514&lon=-73.90455&zoom=17&layers=M
>is a subdivision, not wetland or wood. If you're importing Canvec data
>could you please make sure to do some plausibility checks, based on
>aerial imagery or road layout, especially in populated areas? I'm not
>sure how old the imported data is, but some areas supposedly covered
>by woods or wetlands look like they've been developed for quite some
>time.
>
>Cheers,
>Harald.
>
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