[HOT] [Talk-ca] Flooding in Richelieu River, Quebec

Daniel Begin jfd553 at hotmail.com
Sat May 28 18:08:37 BST 2011

Hi all,

an image interpretation of the flooded area of Haut-Richelieu has been
uploaded, replacing the first work done by Pierre (Thanks to Pierre) .It's
time to put our boots on the ground - in the water?!!




From: Jean-Guilhem Cailton [mailto:jgc at arkemie.com] 
Sent: May-28-11 07:07
To: Daniel Begin; Pierre Beland
Cc: 'HOT Openstreetmap'; 'talk-ca'
Subject: Re: [Talk-ca] [HOT] Flooding in Richelieu River, Quebec, Canada
:Follow-up(Complement of information)



Great find Daniel !

To use directly the GeoTiff images in JOSM, you could try the
ImportImagePlugin, but I haven't tried it.

I put the EO1-ALI images from Earth Observatory online, in WMS and TMS, with
the coordinates included in the GeoTiff files. 

Apparently, they were not georeferenced in relation to ground control
points, but with the imagery layer shift option included in Josm, it is not
too difficult to align them to existing data. For example, a shift of "197;
-514" quickly adjusted over Venise-en-Québec seems to give a reasonable
alignment in other areas of the images too.

We could try to improve the georeferencing of the original images with
ground control points, but for now it seems that having a try at mapping the
flood extent with the current setup has higher priority. Let me know if you
think more work on georeferencing would be useful.


For the natural color image in TMS (recommended over WMS), use the following
link in Josm:

For the shortwave infrared image in TMS:

The base WMS URL is : 

Thus, for the natural color image in WMS, use the following link in Josm:

For the shortwave infrared image in WMS:

Now on to OSM-style-collaborative-iterative flood extent mapping, without -
and probably then with - boots :)

Best wishes,


Le 28/05/2011 05:53, Daniel Begin a écrit : 

Hi all,


I've tried to "put my boots on the ground" without  going there !-).  I
found a pretty clear satellite image of the river at its max level (30-31m)
- which doesn't really changed since ...




I made few geometric adjustments to the image and compare the result with
30m GeoBase and SRTM contours. Geobase contours gives better results between
St-Jean and L'Île aux Noix but from there to the US boundary, neither
GeoBase nor SRTM is right.


I'm trying to produce a flooded area from DEM data while I'm looking at an
image that contains what I'm looking for - the flooded area!  Why not
mapping from it? I understand the image can be used -


Any idea on how I can use this GeoTiff image in JOSM?








pgp 0x5939EAE2
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