Hi Serge,
Thanks for your detailed feedback.
OK. We can treat these as three separate projects.
Here's one changeset for manual import of lakes:
http://www.openstreetmap.org/browse/changeset/13407137
Here's one for improving the coastline with the landcover:
http://www.openstreetmap.org/browse/changeset/12827842
We'll take a look at simplification. The density of vertices varies.
Sometimes its just right, sometimes too dense, and sometimes not enough
vertices.
No plans for rivers, except if they are big enough to be represented by
polygons.
I wish I could in SF, but I can't make it. I'll try to make the hangout
tonight.
Thanks,
Brian
On 5/31/2013 10:48 AM, Serge Wroclawski wrote:
On Thu, May 30, 2013 at 11:11 PM, Brian May <[email protected]> wrote:
Hi List,
Hi Brian!
Thanks for joining and getting involved!
Another OSM user and I are proposing to tackle manually importing water
derived from the land cover shapefiles produced by the Water Management
Districts. In addition, we will update coastlines. We would also like to
explore utilizing the wetlands and forest polygons from the land cover,
however, I know there are potential problems with shared polygon borders and
I'm not sure the best way to go about that.
This is a lot, so for my own clarification, I'd like to break these
down. So if I understand you correctly, you're looking to:
1. Update water areas (lakes, ponds)
2. Update of coastlines
3. Wetlands and forests
For the sake of managing complexity, I think it'd be easiest to think
of these as entirely separate tasks, even if they're from the same
dataset.
I'm going to be speaking about the lakes and ponds, and not about 2,
3, which I think warrant their own discussions. Would you be willing
to hold off on those until the water features are done?
I have seen a fair amount of NHD data that has been imported in parts of
Florida, and from what I have seen so far, the water polygons derived from
land cover are much more accurate, detailed, and up-to-date.
That would make sense, and it's a shame Florida (like so many other
states) have poor data. But we have a wonderful opportunity to improve
the situation!
Some manual import work using this data has already been done, so partly
we're "coming clean". I have read the import guidelines and kept up with
this mailing list. In the past, I have subsetted out the water from the land
cover SHP by selecting it in ArcMap and exporting to a new shapefile. Then
used shp-to-osm to convert to OSM XML, loaded it into JOSM, and then
copy/pasted the ways into the main OSM layer.
Can you paste some of your changesets?
My view is that so long as:
1. The data is properly licensed
2. You're making proper attribution (wiki page and then source= in chageset)
3. You're doing data conflation and not simply plopping it down on top
of the existing data
4. The new data is accurate
5. The data is properly tagged
6. The new data is properly simplified
Then there's nothing wrong with this kind of import, and manual
imports are, for the most part, better.
It sounds like you've gotten the message about some of these and are
taking corrective action, so that's great. I want to stress that most
of the time, data from external sources needs to be simplified before
inclusion in OSM, so you'll want to add that to your process.
And if you need any help, we can certainly help you!
So, the next steps are to further flesh out the wiki page detailing the
process, provide some sample OSM files for review, and discuss with the US
OSM community before we do any more importing. We would also welcome any
others who have an interest in helping out with the effort.
Sounds good, and if you'll be in SF this week, I think I'll set up a
BoF after my import talk (not immediately after, but at some point
during the conference).
Usually with imports there's an issue of update. I'm personally less
worried about updates on these water features. Lakes rarely change.
Rivers and streams do need to be handled differently, though, and if
you have any of them, we'll want to address them separately from the
ponds and lakes.
Thanks again for joining and making everyone aware of the work you're
doing. If you'll be in SF, please point yourself out!
- Serge
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