[Talk-us] NHD Dataset

Christopher Schmidt crschmidt at metacarta.com
Mon Feb 16 15:56:57 GMT 2009


On Mon, Feb 16, 2009 at 10:37:05AM -0500, Theodore Book wrote:
> I think it would be great to get it all in as soon as possible.  I do 
> see a few limiting factors, though:
> 
> * In some places, a lot of work has been done manually entering water 
> features.  While I expect the NHD data is generally better, we have the 
> tough issue of respecting other people's work (and not duplicating 
> things in the database)
> 
> * The upload speed seems to be a limiting factor - it is taking me some 
> 70-80 hours to upload the one basis with bulk_upload.pl.  I am not sure 
> how many basins there are in the country, but it seems as though it 
> could take a year if it were all done sequentially.

If you're not uploading from dev.openstreetmap.org, there's probably a
significant speedbump to be gained from doing so. Additionally, once the
0.6 API is up, we can group a lot of changes into changesets: a *huge*
chunk of the time spent when uploading remotely is spent on round trip
to the server, nothing else. 

> * The scripts I used to convert the shapefiles to OSM only supported the 
> features I found in this one basin.  They should be easy to extend, (or 
> someone else may have better ones), but they would need to be tested.

What script did you use for doing the polygons themselves? Did i t
support splitting of large polygons into smaller ways?

Regards,
-- 
Christopher Schmidt
MetaCarta




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