Hello All,<br><br>I am working on preparing to import subbasin 01080105 of National Hydrography Dataset data (<a href="http://wiki.openstreetmap.org/wiki/National_Hydrography_Dataset">http://wiki.openstreetmap.org/wiki/National_Hydrography_Dataset</a>) . This is the White River subbasin in Vermont. I think I have done a pretty decent job of preparing the data to import, by simplifying shapes, using ogr2osm (which handles duplicate nodes) and breaking up large areas into more manageable sizes. I am fortunate (as far as the import goes at least...) that there are few water features already mapped in this area, which I am taking steps to avoid copying/overwriting. Not only that, but the mappings from the source data to the stream vs river distinction seems fairly straightforward and obvious.<br>
<br>My primary concern is importing the data in a format which will be easiest to work with even for new OpenStreetMappers. I don't want to import any more tags than are necessary, as I have worked with some imported data that in my opinion have too many tags with incomprehensible data (tiger:separated, tiger:upload_uuid, tiger:tlid, etc for TIGER and probably better examples in MassGIS imports around Boston). I tend to believe that these extra tags simply confuse or slow down the mapping process for users and may even have a negative affect on the OSM community. I hope the result follows K.I.S.S. as much as possible.<br>
<br>So these are my ideas about which I am asking for some validation or suggestions:<br><br>- The waterbody data in the source contains a field 'AreaSqKm'. This is
the surface area of waterbodies. This seems pointless to import as it
could presumably be calculated from the shape itself, and will
(hopefully!) become wrong and out of date when waterbody areas are updated by users.<br><br>- There are a few tags in the source data which have the exact same
key/value pair for every single feature. FDate (date of last feature
modification) is one of these fields. I believe these tags would be
better added to the wiki page of the dedicated import user and not added as tags to the features. There are a few other fields in this category:<br>
--- Resolution - value is High for every single feature<br>
--- FTYPE - There are only two values across the source data, which are also covered by FCode. <br>
--- FCode - this seems like it will be completely useless to mappers once the data is in OSM.<br><br>
- My upload test plan is to upload to one of the dev servers and see if
it works. I think I can then wait for and watch the watershed appear on the dev map. At
that point I will attempt to roll back/revert the upload on that dev
server. I will then watch the rivers disappear from the map. Will that be sufficient?<br><br><br>And my questions are:<br><br>- Features in the import data generally have two identifying fields, ReachCode and ComID. They both seem to be defined as nationally unique identifiers, with the ComId as the 'National Database Key'. However I suspect that soon after importing either I or others will want to combine ways sharing the same ReachCode (which are adjacent) but with different ComIDs. The main rivers are composed of a lot of short segments with just a few nodes each (rivers are split into separate polylines every time waterways come together). Because the ComIDs identify the individual polylines in the source data, this means that ComIDs will not map cleanly and would either be appended together or lost (like tiger:tlid from what I can tell) when ways are joined. What is the utility of these IDs once the data is in OSM? Would it be better to just not import ComIDs to begin with?<br>
<br>- Any suggestions on which tool to actually upload the data? I will be uploading roughly 175,000 nodes, 7520 ways and 20 relations. The combined OSM file is about 19 MB. Is JOSM a viable option in this case? It seems like the two best options are upload.py and bulk_upload.py (which I would be comfortable writing a script for). I will most likely be uploading on a typical low/medium speed residential cable connection. <br>
<br><br>Anyway, sorry I can be verbose! :) I have my data in near finished form on Dropbox if anyone would like to review it. I am also planning to move my process documentation to a wiki page in the near future.<br><br>Thank you very much!<br>
<br>Scott<br>