Elliott Plack <[email protected]> writes:
I would argue that importing land-use that is difficult or tedious to trace...encourage(s) local mapping...
I agree. OSM user nmixter and I contributed to a comprehensive landuse import in Santa Cruz County California starting in 2009. You can read the details at our County's wiki page, but over three versions and five+ years, this is now reasonably up-to-date with two-year-old (the latest) data. While painstaking manual updating of over 3000 (multi)polygons was required, we (largely I) did it, because we should have. Santa Cruz even won a Gold Star Award from BestOfOSM.org, one of only a handful of North American locations to receive this accolade. From the site: "...nearly perfect landuse!" And as newer landuse data become available, published by our County GIS Department, we (I, likely) will update/import these to version 4. That's what it takes, so that's what we do.
We have many active local contributors, including students from our local University of California campus via numerous (Computer Science, Environmental Studies...) classes, as well as the Transportation Department adopting OSM for the campus' official basemap at http://maps.ucsc.edu. The map is plastic enough to accommodate all of these uses, AND be a useful academic tool at the same time. Just have respect for the data, follow good, simple rules and have fun!
1. It shows others that an area of the map has received some attention.
Yes, it certainly does! However, a landuse import must be done well, with an eye towards quality, accuracy and even beauty, rather than simply be a bad excuse for "spilling large buckets of paint" (farmland, meadow, residential...) all over the map with poorly-chosen, giant landuse= (multi)polygons. Please be careful not to do this; a landuse import is a balancing act. For example, we know that our landuse import, which might result in what some think of a "zoning map" (it is much more than that) is really a first draft for much more comprehensive OSM data input in the future. It ENCOURAGES these additional data entries by taking the map from "empty" to "rough (but accurate) sketch" to "now that others have gotten you started, please draw as much beautiful detail as you are able to."
2. It produces "gaps," i.e. places where there are no wetlands or water thus leaving a gray "hole" on the map, thus a mapper might look there to add something, such as a camp site or some unknown settlement.
In our County, this draws special attention to parks that haven't been named properly, so-called "special_use" parcels (some turn out to be landuse=industrial like a water tower or sewage treatment), sharpening up differences between residential farmland (so-called "live-on" family farms) vs. more commercial farmland like orchards, vineyards and row crops and it allows boundaries (e.g. of public lands) to be improved, TIGER roads to be called attention to with obvious errors so they can be improved, and more.
3. It exposes inaccurate TIGER roads and tracks, as these typically are on embankments through wetlands.
As I just said. Sometimes TIGER roads and tracks follow a property boundary, and if a landuse import is accurate, it can be used to supercede the TIGER road or track, allowing obvious improvement.
Importing landuse adds visual beauty to the map in places where it would take hordes of volunteers to trace wetlands, and experts to determine the wetland classification. I think this is a good idea.
And not just in wetlands, though I do agree. In our world (2/3 of our County is wooded) it was found that a tag of natural=wood (where landuse=forest, or an active timberland) was appropriate for many parcels (such as special_use) that otherwise wouldn't render. When superimposed with the simple task of tracing existing landuse=meadow polygons over these woods, forests and parks, the effect is both accurate and visually quite pleasing. (See, for example, the rather pretty -- and accurate -- contrasts between wooded/forested areas and farms, parks and meadows at http://www.osm.org/#map=16/36.9712/-122.0778).
I've fiddled around with NWI data and OSM and usually the result is great. While I'd concede that landuses do change, so to do other features that are imported often (buildings and such). A map is always a snapshot in time, and for the most part land use within a protected area is not subject to much in the way of change.
Likewise. We (OSM volunteers) don't often talk about the importance of KEEPING UP the map after an import, but doing so is a seriously crucial component. Thank you, Elliott, for calling this to our attention. Some updates need relatively frequent updating, some almost none at all.
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