OpenStreetMap

Haiti Administrative Boundaries

Posted by EdLoach on 29 January 2010 in English (English)

I've recently been helping tidy up the Haiti administrative boundaries that had been imported into OSM. Relations were created, overlaid ways were split at appopriate places, tags were moved from ways to relations and most recently I've been updating admin_levels to be the lowest number as per the wiki documentation.

A quick look at OSM shows the Departments at this zoom level 8. At zoom level 11 admin levels 4 (department) and 5 (arondissiment) are visible, and zooming in to zoom level 12 shows the admin level 8 (commune) boundaries. The admin level 10 boundaries (the pcode:3 level districts) become visible at zoom level 13. Only a subset of these last boundaries have to date been imported.

I wanted a quick way to visually see which of the pcode:3 districts had been imported, so learnt how to use a Xapi request to retrieve all boundary=administrative tagged relations in a certain bounding box (I found the numbers from that by using the Export tab and drawing the area I wanted manually, then copying them from there). With the 14.5MB data.osm file I got back from that I loaded it into Kosmos and made a set of rules to cover different administrative levels in different colours (this always takes me trial and error, but the set I'm currently using is here).

The resulting picture is on Flickr - a small version of it is included here:
Haiti Administrative boundaries from OSM as at 29/01/2010

If more of the admin_level 10 boundaries are imported I suspect there will be more work to do merging the new ways with the existing ones that they will probably overlay. If this happens then I will produce an updated diagram.

I had hoped to produce different maps showing pcode:1, pcode:2 and pcode:3 labels at appropriate zooms, but AreaCenter in Kosmos doesn't seem to work with relations and it doesn't seem to like colons in tags, as I could get the name value in the wrong place but got no errors or text when trying to use the pcode:3 value instead. Perhaps I should try and learn how to play with Mapnik...

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