[Talk-ca] [HOT] Flooding in Richelieu River, Quebec, Canada :Follow-up (Complement of information)

Fri May 27 12:12:10 BST 2011

Very thanks to Sam Vekemans, Brent Fraser and Jean-Guilhem Cailton for their suggestions and help.

Jean-Guilhem Cailton wrote on 201-05-27
> The 30 m contour lines from tiles 031h03 and 031h06 (the shapefiles you gave), 
> potentially connected to Richelieu river, have been imported, and put together
> in relation: http://www.openstreetmap.org/?relation=1602671

Jean-Guilhem, I will use this information for a basis of discussion, and see how it can reflect the flooded zones. Could you easily add to the relation, the 30m elevation for Missisiquoi Bay where Venise-en-Quebec town has been severely affected by floods?

regards,

Pierre Béland 
2011-05-27  

De : Jean-Guilhem Cailton 
Date/heure : 2011-05-27  05:19:54 
A : Pierre_Béland 
Cc : Brent Fraser; HOT Openstreetmap; talk-ca 
Sujet : Re: [Talk-ca] [HOT] Flooding in Richelieu River, Quebec, Canada :Follow-up (Complement of information) 

Hi Pierre,

The 30 m contour lines from tiles 031h03 and 031h06 (the shapefiles you gave), potentially connected to Richelieu river, have been imported, and put together in relation:
http://www.openstreetmap.org/?relation=1602671

Clearly, it is not enough to estimate the flooded zone, for which some kind of flow analysis would be needed, but maybe it can help in some areas, as you wrote.

I used "ogr2ogr -where ELEVATION=30 ..." to extract the 30m contour line, and ogr2osm.py to convert it to .osm, for Josm.

Best wishes,

Jean-Guilhem

Le 27/05/2011 06:30, Brent Fraser a écrit : 
Pierre,

I can't comment on if the 30m contour solution is suitable, but if you want to extract the 30m contours, you could:

1. Use QGIS to extract 30m contour from *_FO.._1.shp files
        - load shapefile, Open Attribute Table, click on elevation field name to sort table by elevation value.
        - select all 30m values, click on Layer -> Save selection as vector file. Save shapefile 

2. Use converter (one of the ones on http://wiki.openstreetmap.org/wiki/Import/Shapefile) to create .osm files
        (I haven't tried this)

3. Use Josm to load osm files, tag, and update to OSM

Best Regards,
Brent Fraser

On 5/26/2011 8:46 PM, Pierre Béland wrote: 
Many osm volunteers have worked in the last two days to correct roads, complete Canvec import and add street names.

An other task is to estimate the flooded zone along the Richelieu River and Missisquoi Bay in Lake Champlain. One simple approach to determine the flooded zones would be to use the 30 meter contour line from Canvec data. This would be good at least for Richelieu River.

These maps from Natural Resources Dept of Canada shows the 30 meter contour line. For the areas I visited last week with volunteers, this line delimits approximately the flooded zone. On monday 23, water level of the Richelieu river went up to approximately 30.8 meters in Saint-Jean-sur-Richelieu.

Would it be a good solution to estimate the flooded zone ?
If so, any idea, how we can extract 30 meter contour line from shape files using a tool such as Quantum GIS and convert to OSM ?
ftp://ftp2.cits.rncan.gc.ca/pub/canvec/50k_shp/031/h/canvec_031h03_shp.zip
ftp://ftp2.cits.rncan.gc.ca/pub/canvec/50k_shp/031/h/canvec_031h06_shp.zip

Below is an example of Toporama map for Saint-Jean-sur-Richelieu, the wms version of Canvec, where we can see the 30 meter contour line.
http://atlas.nrcan.gc. ca/auth/english/maps/topo/map?mapsize=525%20466&mapxy=1700511.0503883713%20-122536.87132125527&scale=20000.000000&feature_na=Saint-Jean-sur-Richelieu&searchstring=saint-jean-sur-richelieu&layers=fapfeature%20nodata_ntdb_50k%20north_arrow%20other_features%20roads%20hydrography%20boundary%20builtup%20vegetation%20populated_places%20railway%20power_network%20manmade_features%20designated_areas%20water_features%20water_saturated_soils%20relief%20contours%20toponymy%20contour&map_layer[northarrow]_class[0]_style[0]=ANGLE%20-19.595747561783185&urlappend=%26unique_key%3D8dd3e319d1e111d892e2080020a0f4c9%26map.layer[textzoom03]%3DFEATURE+POINTS+1699114.16619+-120243.877124+END+TEXT+%22Saint-Jean-sur-Richelieu%22+END%26map.layer[textzoom46]%3DFEATURE+POINTS+1699114.16619+-120243.877124+END+TEXT+%22Saint-Jean-sur-Richelieu%22+END%26map.layer[arrowzoom03]%3DFEATURE+POINTS+1699114.16619+-120243.877124+END+END 

regards

Pierre Béland 

De : Pierre Béland 
Date/heure : 2011-05-24  18:59:16 
A : HOT Openstreetmap 
Cc : talk-ca 
Sujet : [HOT] Flooding in Richelieu River, Quebec,Canada : Follow-up (Complement of information) 
Following are the ways and relation I have produced to document Richelieu River flooding.  

Affected zones (These will be revised when I obtain more detailed information on streets / areas affected.

http://www.openstreetmap.org/browse/way/114705927 

http://www.openstreetmap.org/browse/way/114705926 

http://www.openstreetmap.org/browse/way/114705928

http://www.openstreetmap.org/browse/way/114706976 

Boundary relation that could be used to produce Indexed map of streets with tools such as Mapsomatic
http://www.openstreetmap.org/browse/relation/1600039 

Pierre Béland 

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