On January 6, 2019 at 7:50:44 AM PST, brad <bradha...@fastmail.com> wrote:
>
> Joseph, I'm not stuck on class 27, but as you say, that fits the definition
> on the wiki. I should probably look for other specific protection in the
> attributes and translate that somehow. Mostly it's just grazing and
> recreation land. Anything such as wilderness or monument would definitely
> be tagged as such.
I agree with this approach, especially "look for other...attributes and
translate (them)." However, this is not something Brad "should probably" do,
it MUST be done to correctly import these data: each parcel must be examined
as to its landuse (in the generic sense, not the OSM tag) and assigned an
appropriate protect_class, especially if it is not 27. The protect_class key
may not render today (though, Carto will hopefully "fix" this with likely
progressively improving methods in the future), that is a separate issue I
specifically point out so additional tags (such as leisure=nature_reserve) do
not get added superfluously ("tagging for the renderer") to make them "appear."
Beware this slippery slope, knowing that even a perfect, completed BLM import
will (today) be essentially invisible in virtually all renderers. The data
being in the map is a good goal, even while rendering them can be put off until
another day (though, not forever).
> Martijn, Gaia is not available on a Garmin, or on a PC. It also costs $40 a
> yr. Why do you trust Gaia as an authoritative source? How often do they
> update from government sources? BLM boundaries do not change very often.
> Probably less often than city/town boundaries. For an authoritative
> source, I have national forest maps that are 10 - 20 years old. A download
> today from a federal database is way better than that and in 5 years will
> probably still be just as good. In relatively sparsely populated areas, on
> the ground verification does not work as well as it does in the city. If
> we make OSM more useful for more people then more folks will get involved.
As a segue from my recent comments on USA rail being about 40% done (over a
decade since their nationwide TIGER import), with such challenges (importing
nationwide data such as BLM boundaries) come great responsibilities. To
repeat: we imported "all" (that TIGER had) of US railroad data and here we
are, eleven, twelve years later at about 40% completion of reviewing, improving
and reporting on their status. Such nationwide tasks (in the USA) are
Herculean efforts, though breaking things up into wikis / efforts at a state
level has proven effective (if relatively slow, it does make logical sense
given state DOTs create rail inventory / planning reports every so often, which
help a lot). Should this BLM data import progress, Brad needs to know how
large an elephant this is to eat. I began similar importation of national
forest (and wilderness, national grassland...) data in California between
2012-3 but abandoned doing so, as the effort simply overwhelmed my ability to
either do this myself or do it with the coordinated effort of other OSM
volunteers. I cannot emphasize this enough: to do and manage these kinds of
national-level data management tasks is an absolutely huge undertaking and I
speak from extensive experience at either attempting or (partially,
successfully, unsuccessfully) completing two or three of them (national rail,
national bicycle routes, NF/Wilderness/BLM/other federal lands).
> Michael, You bring up some good questions which I don't have the answer for
> yet. I would get started with what you call the low road, state sized or
> smaller pieces at a time. A quick look at the boundaries around me show none
> that follow a watercourse or a ridge, they are all straight lines and and
> square corners. The extraneous ways at state boundaries look like artifacts
> from cutting up a larger database into state size chunks. There was no
> polygon, or a skinny polygon associated with those artifacts. I'm guessing
> that there is BLM land in the adjacent state.
I enthusiastically encourage an initial pilot project of a single
state-at-a-time's worth of data. It is far easier to scale up (or abandon)
something you can bite and chew (and swallow and digest) rather than try to
scale down a disastrous import that is so large you (and OSM) choke on it.
> Dave, Thanks for being a voice of reason!
I also agree with Dave's and Brad's assertions that these data belong in OSM.
Publicly-owned BLM lands afford numerous recreational, educational and other
opportunities, similar to leisure=park, leisure=nature_reserve and related
areas. Denoting where these are with recent federally published data is in
complete harmony with other sorts of boundaries in OSM. But there is wishing
or agreeing that the data belong, then there is doing a high quality job of
importing and maintaining them. The former is relatively easy, the latter is
actually quite difficult, though it can (and imo should) be done.
SteveA
California
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