OSMBorder

OSMBorder extracts the admin boundary data from an OSM planet file and assembles all the pieces into linestrings for use in map renderers etc.

Prerequisites

Libosmium

https://github.com/osmcode/libosmium
http://osmcode.org/libosmium
At least version 2.7.0 is needed.

zlib (for PBF support)

http://www.zlib.net/
Debian/Ubuntu: zlib1g-dev

Pandoc (optional, to build documentation)

http://johnmacfarlane.net/pandoc/
Debian/Ubuntu: pandoc
(If pandoc is found by CMake, the manpages will automatically be built.)

Building

You'll need the prerequisites including libosmium installed.

OSMBorder uses CMake for building:

mkdir build
cd build
cmake ..
make

Call make doc to build the Doxygen API documentation which will be available in the doc/html directory.

Testing

Running

Filter the planet with osmborder_filter

osmborder_filter -o filtered.osm.pbf planet-latest.osm.pbf

Create linestrings with osmborder

osmborder -o osmborder_lines.csv filtered.osm.pbf

Output

OSMBorder outputs a tab-delimited file that can be loaded directly into PostgreSQL. This requires a suitable table, which can be created, loaded, optimized, and indexed with

CREATE TABLE osmborder_lines (
  osm_id bigint,
  admin_level int,
  dividing_line bool,
  disputed bool,
  maritime bool,
  way Geometry(LineString, 3857));
\copy osmborder_lines FROM osmborder_lines.csv

CREATE INDEX osmborder_lines_way_idx ON osmborder_lines USING gist (way) WITH (fillfactor=100);
CLUSTER osmborder_lines USING osmborder_lines_way_idx;
CREATE INDEX osmborder_lines_way_low_idx ON osmborder_lines USING gist (way) WITH (fillfactor=100) WHERE admin_level <= 4;

The indexes are optional, but useful if rendering maps.

Tags used

OSMBorder uses tags on the way and its parent relations. It does not consider geometry, relation roles, or non-way relation members.

admin_level

The admin_level is the lowest admin_level value of the parent relations. The way tags are not considered.

disputed

The presence of disputed=yes, dispute=yes, border_status=dispute or disputed_by=* on the ways is used to indicate part of a border is disputed. All the tags function the same, but disputed=yes is my preference. Relation tags are not considered.

maritime

maritime=yes, natural=coastline or boundary_type=maritime indicates a maritime border for the purposes of rendering. Relations are not considered, nor intersection with water areas.

Options

-v, --verbose

Gives you detailed information on what osmborder is doing, including timing.

Run osmborder --help to see all options.

License

OSMBorder is available under the GNU GPL version 3 or later.

Authors

Paul Norman (penorman@mac.com)
Based on OSMCoastline by Jochen Topf (jochen@topf.org)

pnorman / osmborder