Minimal initial data

Important

These data are the minimal initial data required to have a functional Geotrek-admin after completing the installation.

Altimetry (DEM)

Keywords

DEM, MNT, raster, QGIS

Data sources recommandations

Altimetric Data

Name

Provider

Coverage

Resolution

Format

BD Alti

IGN

Departmental

25 m

.asc

RGE Alti

IGN

Departmental

1 m or 5 m

.asc

Warning

  • We recommend not importing a DEM with too precise resolution for performance reasons. For example, the BD Alti DEM with a 25m resolution is perfect to cover a department.

  • If you downloaded the BD Alti or RGE Alti, you will need to convert the .asc DEM to .tif format (e.g. with QGIS) before uploading it on the server.

In QGIS, you can visualize your DEM, or merge several tiles together (in Raster > Misc > Merge).

Generate a GeoTIFF, and upload both files (.tif + .tfw) on the server. And use the Geotrek-admin command to load it into PostGIS :

sudo geotrek loaddem <PATH>/dem.tif

Note

  • This command makes use of GDAL and raster2pgsql internally. It therefore supports all GDAL raster input formats. You can list these formats with the command raster2pgsql -G.

  • The elevation data of DEM must be integer values. If the elevation data are floating numbers, you can convert them in integer values with the Raster calculator processing of SAGA in QGis (Processing > Toolbox > SAGA > Raster calculus > Raster calculator) with formula parameter set to int(a).

  • If you only have a .tif file, you can generate the .tfw file with the command gdal_translate -co "TFW=YES" in.tif out.tif. It will generate a new .tif file with its .tfw metadata file.

  • If you want to update the altimetry of the topologies you need to use the option --update-altimery

Load DEM

Refer to this section to learn how to load DEM with the loaddem command.

Paths

Keywords

command line, import en ligne de commande, QGIS

✨ Only available in dynamic segmentation

Important

With dynamic segmentation, importing paths is very risky if paths are already present in the same area in Geotrek, it is only safe for an area where no path is already created.

Indeed, if you import paths where there are existing paths, treks, POIs or trails linked topology might be impacted.

Step 1: Prepare the paths to import

By exporting paths from OpenStreetMap

You can use the osm-paths tool to download OSM paths data via the overpass API. This tool converts paths into linestrings and exports them to GeoJSON.

For more information, refer to the osm-paths documentation

By using your own paths

Requirements

Before importing paths layer, it is important to prepare them. Here are the requirements:

  • valid geometry

  • simple geometry (no intersection)

  • all intersections must cut the paths

  • not double or covering others

Cleaning your paths

We use QGis to clean a path layer, with plugin Grass. Here are the operations:

  1. Check the SRID (must be the same as in Geotrek)

  2. Use the Geometric tools:

    1. Go to Vectors → Geometric tools → “Collect geometries”.

    2. Then go to Vectors → Geometric tools → “Group”.

  3. Clean geometries:

    1. Search for v_clean in the Processing toolbox.

    2. Select the following options in the cleaning tool:

      • break

      • snap

      • duplicate (or rmdup)

      • rmline

      • rmdangle

      • chdangle

      • bpol

      • prune

    3. In threshold, enter 2,2,2,2,2,2,2,2 (2 meters for each option).

  4. Delete duplicate geometries:

    1. Search for duplicate in the Processing toolbox.

  5. Regroup lines:

    1. Search for v.build.polyline in the Processing toolbox.

    2. Select first in Category number mode.

Step 2: Import the paths into your instance

There are two ways to import paths:

Step 3: Pre-generate the path graph

After importing a large quantity of paths, it is recommended to pre-generate the paths graph needed for the routing.

This action is not mandatory, but will reduce the time needed for the first routing following the import.

To pre-generate the graph, use the generate_pgr_network_topology command. Refer to this section to learn about this command.

Areas

Cities

Data sources recommandations

Administrative Boundaries Data

Name

Provider

Coverage

Scale

Format

Update Frequency

Admin Express (COMMUNE)

IGN

Metropolitan France, Overseas Territories

Municipality

Geopackage, Shapefile

Annually

Administrative Boundaries ➡ Communes

Etalab

Metropolitan France, Overseas Territories

Municipality

GeoJSON

Annually

See also

Refer to this section to learn more about loading cities in your Geotrek-admin.

Districts

Data sources recommandations

Administrative Boundaries Data (EPCI)

Name

Provider

Coverage

Scale

Format

Update Frequency

Admin Express (EPCI)

IGN

Metropolitan France, Overseas Territories

EPCI

Geopackage, Shapefile

Annually

Administrative Boundaries ➡ EPCI

Etalab

Metropolitan France, Overseas Territories

EPCI

GeoJSON

Annually

Districts are not necessarily administrative boundaries. They can be intercommunalities, departments, parks, or natural regions. The advantage of importing them as Districts is that you will be able to filter them in Geotrek-rando, which will not be possible with Restricted areas.

See also

Refer to this section to learn more about loading districts in your Geotrek-admin.

Restricted areas

Data sources recommandations

Protected Areas Data

Name

Provider

Coverage

Format

Update Frequency

Natura 2000

INPN

Metropolitan France, Overseas Territories

Shapefile

Annually

ZNIEFF1

INPN

Metropolitan France, Overseas Territories

Shapefile

Annually

ZNIEFF2

INPN

Metropolitan France, Overseas Territories

Shapefile

Annually

ZNIEFF1 Mer

INPN

Metropolitan France, Overseas Territories

Shapefile

Annually

ZNIEFF2 Mer

INPN

Metropolitan France, Overseas Territories

Shapefile

Annually

Biotope Protection Orders

INPN

Metropolitan France, Overseas Territories

Shapefile

Annually

National Nature Reserves

INPN

Metropolitan France, Overseas Territories

Shapefile

Annually

Regional Nature Reserves

INPN

Metropolitan France, Overseas Territories

Shapefile

Annually

Biological Reserves

INPN

Metropolitan France, Overseas Territories

Shapefile

Annually

See also

Refer to this section to learn more about loading restricted areas in your Geotrek-admin.

Sensitive areas

Data source recommandation

Sensitive Natural Areas Data

Name

Provider

Coverage

Format

Update Frequency

Sensitive Natural Areas

INPN

Metropolitan France, Overseas Territories

Shapefile

Annually

See also

Refer to this section to learn more about loading sensitive areas in your Geotrek-admin.