Overlay historical polities on modern country/state borders

[edwardchalstrey1]

Overlay modern countries states/provinces with polities on the same map This should be a single Django template with the option to switch the basemap between the GADM shapes or OSM (or CartoDB)

• [x] Have provinces as the basemap
• [x] Try OSM basemap with borders on another branch.
• [x] Make sure GADM is only displayed over carto
• [x] Also allow countries as basemap and toggle with radio button
• [x] Choose an appropriate simplification_tolerance
• [x] Figure out a good colour for the base shapes
• [x] How should the name/type of provinces and names of countries be displayed? Clicking them won't work well if there's another shape on top
  • Add a toggle for showing the polity shapes

[edwardchalstrey1]

Some of the "provinces" (second level in the GADM dataset) are very small (making it slow to load) and there is a massive inconsistency across the globe too, which I think reduces the usefulness of this level

[edwardchalstrey1]

The code I used to populate the provinces table, which perhaps could be modified with some bespoke rules that don't treat all countries the same:

        INSERT INTO core_gadmprovinces (geom, "NAME_1", "ENGTYPE_1")
        SELECT 
            ST_Union(geom) AS geom,
            "NAME_1",
            "ENGTYPE_1"
        FROM 
            core_gadmshapefile
        GROUP BY 
            "NAME_1", "ENGTYPE_1";

[edwardchalstrey1]

OSM boundaries