Support points of view (worldview) for admin0 disputed areas areas

[nvkelso]

I've been editing Natural Earth the last year to add support for a wide range of "points of view" (sometimes called worldview). This issue tracks that work, and is related to #108 – this is issue is more general.

More info in the two related Tilezen release notes (summarized below in this issue description):

• https://github.com/tilezen/vector-datasource/releases/tag/v1.8.0
• https://github.com/tilezen/vector-datasource/releases/tag/v1.7.0

I've also been updating OpenStreetMap so it can be used in concert with Natural Earth to show disputed ares:

• https://www.openstreetmap.org/user/nvk/diary/47890
• https://www.openstreetmap.org/user/nvk/diary/390496

There's even a demo map, here showing Kashmir (use the “POV” point-of-view menu in the upper-right corner to toggle the different visual treatments):

• http://tangrams.github.io/bubble-wrap/#5/33.523/-282.281

From the Tilezen release notes:

v1.8:

• boundaries: Add more kind:* point-of-view (POV) from Natural Earth for low zooms for disputed boundary lines, expanding on the v1.7 effort to also include region boundary disputes. (Issue #1840)
  • 
  • To handle disagreements about the location of borders, the kind may be prefixed with unrecognized_, e.g: unrecognized_country (was unrecognized in v1.7), unrecognized_macroregion, unrecognized_region, unrecognized_county for differing viewpoints (see kind:xx below).
  • kind:xx: alternate kind according to the viewpoint of country code xx. If you want to show features according to a particular viewpoint, then use kind:xx if it exists and fall back to kind if not. The range of values is the same as for kind. Note that the viewpoints are either lower-case ISO 3166-1 alpha-2 codes or the pseudo-code iso.

v1.7:

• boundaries: Adds support for alternate points of view in boundaries layer with kind:* properties (like kind:iso). Currently this is only for zooms 5, 6 and 7 from Natural Earth. We plan to add more lower zoom data from Natural Earth, and high-zoom data from OpenStreetMap in the next release. (Issue #1552) The following country and international organizations worldviews are supported:
  • Argentina (ar), Bangladesh (bd), Brazil (br), China (cn), Egypt (eg), France (fr), Germany (de), Greece (gr), India (in), Indonesia (id), Israel (il), Italy (it), Japan (jp), Morocco (ma), Nepal (np), Netherlands (nl), Pakistan (pk), Palestine (ps), Poland (pl), Portugal (pt), Russia (ru), Saudi Arabia (sa), South Korea (ko), Spain (es), Sweden (se), Taiwan (tw), Turkey (tr), United Kingdom (gb), United States (us), Vietnam (vn), ISO (iso)
• boundaries: Add new disputed boundary lines with kind values of disputed_breakaway, disputed_claim, disputed_elusive, disputed_reference_line, from Natural Earth at low zooms, for alternate points of view (Issue #1552)

[nvkelso]

Specifically, add new fclass_* variants per polity POV on:

• admin-0 boundary lines (multiple themes, all scale sets, new property)
• admin-0 country polygons (new download file options)

[nvkelso]

• Adjust min_zoom of disputed lines to be smaller when one or more of their claimants needs them earlier to complete their own country boundary line at lower zooms. See China along India, Pakistan, Bhutan salients.
• QA
• More QA

[nvkelso]

Big write about these changes in #391 (comment).

[nvkelso]

Adjust min_zoom of disputed lines to be smaller when one or more of their claimants needs them earlier to complete their own country boundary line at lower zooms. See China along India, Pakistan, Bhutan salients.

The simplest thing to do is in QGIS (and for vector tiles) is to always include features from the scalerank theme (so remove the min_zoom filters) as for default the current min_zoom is ideal... but otherwise we'd need to include optional min_zoom_{pov} for all the POV and there are an insane number of columns as it is.

If we were to add various min_zoom_{pov} then downstream QGIS and vector tiles would need to take the minimum min_zoom_{pov}for inclusion at that zoom... but that's not something QGIS's basic layer filters are setup for, and the layer styling is already pretty complicated as it is.

[nvkelso]

Fixed via #446.