[Talk-us] NHD Imports

Clifford Snow clifford at snowandsnow.us
Sun Oct 28 00:27:58 GMT 2012

On Sat, Oct 27, 2012 at 5:13 PM, David ``Smith'' <vidthekid at gmail.com>wrote:

> Past NHD imports have made vast multipolygons which can be difficult to
> interpret without a view of the whole thing.  This made particular problems
> for tiles at home/osmarender, which tried to render the multipolygons
> without loading their out-of-area members, leading to water-land inversion
> in a lot of places.  Editing these multipolygons may be error-prone too,
> though need for such editing should be rare.  If you can somehow limit the
> size of the multipolygons, this issue can probably be mitigated.
> Right now I'm only looking to import streams (creeks and rivers) and
possibly small lakes into OSM. I did a small sample of lakes and found them
to be only useful for 1) identifying a lake and 2) getting the name. The
area I'm working with has hundreds of small un-named lakes and a few small
named lakes. It's easy to miss a lake when looking at a bing image so the
data identifies the water. However, the polygon shape from NHD is nothing
like the actual lake on the bing image.

I guess the quick answer is I don't plan to import multipolygons.

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