Minimap Creator

Minimap Creator is a HTTP server for creating minimaps.

Preparation

1. clone the project
2. Run PsotGIS:

   docker run --name minimap-postgis -p 5455:5432 -e POSTGRES_PASSWORD=snakeoil -e POSTGRES_HOST_AUTH_METHOD=trust --shm-size=1g -d postgis/postgis

3. download map data sql and import it to PostGIS:

   pigz -cd dump.sql.gz | psql -h localhost -p 5455 -U postgres

4. save hillshading data as data/hillshading-world.tif
5. install dependencies

   npm i

6. build the project

   npm run build

7. start the server

   PORT=8080 npm start

Map generation

Query parameters, all are optional:

• srs - spatial reference system. Well supported are +init=epsg:3035 (good for Europe) and +init=epsg:3857 (global, default).
• lat, lon - pin latitude and longitude, default no pin
• width - image width, default 800, or computed from country and height if specified
• height - image height, default 400, or computed from country and width if specified
• scale - global graphics scaling factor, default 1
• features - comma separated features:
  • roads - roads
  • borders - global borders (admin_level=2 for country borders, admin_level=4 for region borders); see https://wiki.openstreetmap.org/wiki/Tag:boundary=administrative#10_admin_level_values_for_specific_countries
  • coastlineBorders - draw coastline border and mask maritime borders
  • scale - map scale
  • limitPlacesToCountry - show only places of specified country
  • transliterate - transliterate non-latin names
• simplify - line simplify (generalization) factor, default 2
• colors - override default colors. Syntax: feature:color,feature:color,... where feautre is one of water, urban, forest, pin, border, coastline, areaHighlight, land and color is HTML color.
• place-types - which places to render, comma separated values of: city, town, village. It can also contain a single value capital to only display capitals.
• places - which places to render, by OSM ID or by name
• place-label-placement - label placements to try. Values: U for up, D for down, L for left, R for right. May be combination like UDRL. Default is U.
• place-label-margin - place labels margin, default 20.
• landcover-types - what landcover to render, comma separated values of: forest, water-body, urban.
• country - country to zoom to and to highlight
• major-borders - country codes and admin levels to show as major borders, format: cc:level,cc:level,...; default :2 (admin_level=2 for every country)
• minor-borders - country codes and admin levels to show as minor borders, format: cc:level,cc:level,...
• micro-borders - country codes and admin levels to show as micro borders, format: cc:level,cc:level,...
• border-width-factor - scale of the borders width, default 1
• coastline-width-factor - scale of the coastline borders width, default equals to border-width-factor
• waterway-width-factor - scale of the waterway width, default 1
• place-size-factor - scale of the places, default 1
• highlight-admin-area - OSM ID or name (local or slovak) of the area to highlight
• hillshading-opacity - opacity of the hillshading in range from 0 (no shading, default) to 1 (full shading)
• hillshading-variant - variant of the hillshading, default world
• watershed-name - name of watershed to render
• bbox - explicit bounding box to render (minLon,minLat,maxLon,maxLat)
• margin - map margin in pixels, default 5
• format - output format, one of png (default), jpeg, svg, pdf

Generated map must be enclosed with the following attribution: OpenStreetMap contributors (ODbL 1.0)

Examples

Highlight administrative area and show a marker:

curl 'http://localhost:8080?features=borders,landcover,roads&placeId=522422&country=sk&width=1200&scale=1&margin=20&minor-borders=hu:4,uk:4,at:4,pl:4,sk:4,cz:4&micro-borders=sk:8&place-types=city,town&highlight-admin-area=Ko%C5%A1ick%C3%BD%20kraj&hillshading-opacity=0.5&lat=48.700142&lon=20.891184' | display

Watershed Hornád:

RIVER=hornad

curl "http://localhost:8080?features=borders,landcover,scale&width=1200&scale=2&place-size-factor=0.8&margin=20&place-types=city,town&hillshading-opacity=0.5&watershed-name=$RIVER&bbox="`ogrinfo -sql "select st_transform(st_envelope(st_union(geometry)), 4326) from watershed_$RIVER" data/watershed_$RIVER.sqlite watershed_$RIVER | grep Extent | sed -e 's/[^0-9\.]\{1,\}/,/g' | sed -e 's/^.\|.$//g'` | display

Notes

Preparing map data

1. Obtain latest planet.osm.pbf from planet.openstreetmap.org.
2. Import the data:

   imposm import -connection postgis://minimap:minimap@localhost/minimap -mapping mapping.yaml -read planet.osm.pbf -write -overwritecache
   imposm import -connection postgis://minimap:minimap@localhost/minimap -mapping mapping.yaml -deployproduction

3. Process the data in PostGIS:

   psql -h localhost minimap minimap < process.sql

4. download simplified land polygons and convert it to PosgGIS SQL.
5. Import simplified_land_polygons.sql to PosgGIS:

   psql -h localhost minimap minimap < simplified_land_polygons.sql

6. Dump the data:

   pg_dump -h localhost -U minimap -t simplified_land_polygons -t osm_admin_rels -t border_lines -t admin_borders -t osm_places -t roads -t landcover minimap | pigz > dump.sql.gz

7. Run dockerized PostGIS:

   docker run --name minimap-postgis -p 5455:5432 -e POSTGRES_PASSWORD=snakeoil -e POSTGRES_HOST_AUTH_METHOD=trust --shm-size=1g -d postgis/postgis

8. Load data to dockerized PostGIS:

   pigz -cd dump.sql | psql -h localhost -p 5455 -U postgres

Watershed

Download geopackage(s) from https://land.copernicus.eu/imagery-in-situ/eu-hydro/eu-hydro-river-network-database?tab=download (for example EU-Hydro-Danube-GeoPackage)

Extract waterways of a watershed for a particular river - find its first and last segment object_id and also for its parent.

• Hornád: hornad danube RL35142907 RL35137645 RL35137675 RL35136997
• Dunajec: dunajec vistula RL37002352 RL37004091 RL37004010 RL37004177
• Ipeľ: ipel danube RL35140937 RL35122706 RL35122124 RL35122824
• Hron: hron danube RL35142316 RL35122640 RL35122124 RL35122360
• Kysuca: kysuca danube RL35131906 RL35131464 RL35131304 RL35131518
• Bečva: becva danube RL35132213 RL35131855 RL35131847 RL35131675
• Berounka: berounka elbe RL27008052 RL27009356 RL27009029 RL27009979
• Bobr: bobr oder RL36000033 RL36003020 RL36003045 RL36003091
• Dyje: dyje danube RL35128009 RL35127268 RL35127599 RL35126849
• Jihlava: jihlava danube RL35130614 RL35128643 RL35128423 RL35128414
• Jizera: jizera elbe RL27014232 RL27010591 RL27010611 RL27010903
• Bodrog: bodrog danube RL35141164 RL35139123 RL35139542 RL35138716

scripts/gen_waterways.sh danube hornad RL35142907 RL35137645 RL35137675 RL35136997

Make watershed polygon (QGIS):

1. Clip
2. FlowAccumulationFullWorkflow
3. ExtractStreams (100000)
4. add point to sink
5. Watershed
6. Polygonize (gdal)
7. SmoothVectors (10)
8. Simplify (10)
9. export to data/watershed_{name}.sqlite

SELECT load_extension('mod_spatialite');
delete from admin_areas where ogc_fid = 785489; -- find ID of border making Krym Russian
insert into admin_areas select null, 1 as osm_id, name as name, name_sk, admin_level, country_code, st_union(geometry) as geometry from admin_areas where country_code = 'UA' and admin_level = 2 group by country_code;
delete from admin_areas where country_code = 'UA' and admin_level = 2 and osm_id <> 1;

More resources / ideas

• https://github.com/eurostat/RegionSimplify
  • java -jar regionsimplify-1.4.1/RegionSimplify.jar -i admin.gpkg -s 9244649
• https://gis.stackexchange.com/questions/439271/simplify-multipolygon-removing-small-gaps-in-postgis/439274
• https://gadm.org/