[Talk-ht] Fw: [CrisisMappers] Haiti: road obstruction locations

Frederik Ramm frederik at remote.org
Wed Feb 3 09:49:33 GMT 2010


Nick, Mikel, List -

Nick McWilliam:
> We've had a request from our field team for the most current data showing
> road obstructions, e.g. through landslides or fallen buildings, at a
> national level for Haiti. Ideally each location would be given a source and
> a date. Can anyone advise on the best place to look please?
> 
> I've seen the obstacles layer here (http://haiti.openstreetmap.nl/) but
> don't know how to extract this as a data layer.

If you're willing and able to install and run the "osmosis" tool 
(wiki.openstreetmap.org/wiki/Osmosis) then, armed with the tagging info 
from the "Humanitarian OSM tags" page, you can create any extract you 
want based on a current Haiti datasaet, for example:

osmosis --rx haiti.osm --nkv keyValueList=barrier.obstacle --wx 
obstacles.osm

gives you a list of all (currently 168) points tagged "barrier=obstacle" 
  (note that the command line has a dot instead of an equal sign). To 
retrieve a list of all impassable roads, you'd do

osmosis --rx haiti.osm --wkv keyValueList=impassable.yes --used-node 
--wx impassable.osm

This is slightly different because you're asking for line features. It 
returns 68 results with the current OSM data.

I can also modify the shape files on tools.geofabrik.de/haiti to include 
this data, either bei adding an "impassable" column to the existing 
roads shape (and an "obstruction" column to the points shape), or by 
creating separate impassable_roads and obstruction shapefiles.

Lastly, if you want to be flexible and generate your own shape files, 
you can do that (among others) with the Ruby software "osmlib", 
documented here:

http://osmlib.rubyforge.org/osmlib-export/rdoc/index.html

Bye
Frederik




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