In short

  1. Collect all the parts. A shapefile is several files with the same name: .shp (shapes), .dbf (attributes), .prj (coordinate system) and often .cpg (encoding). Zip them together, or select them together.
  2. Open them in the converter. Drop the zip or the files on the shapefile converter or the checker. The coordinate system is read from the .prj.
  3. Answer the coordinate question if asked. If there is no .prj and the numbers are metres, the converter works out the UTM zone from the country when only one fits, and asks you when more than one does.
  4. Check the attribute mapping. Columns such as producer, country and area_ha are mapped to ProducerName, ProducerCountry and Area. The mapping is listed; correct anything it got wrong in the editor.
  5. Fix, check and download. Fix what the checker reports, then download the GeoJSON.

Shapefiles are the lingua franca of GIS: forestry departments, surveyors and certification bodies all produce them. They carry two things a GeoJSON file for the Information System must get right (the coordinate system and the attribute names), and they spread them across several files.

The parts, and what goes wrong without them

FileHoldsWithout it
.shpThe shapesNothing to convert
.dbfThe attribute tableNo producer names, countries or areas
.prjThe coordinate systemMetres cannot be converted safely without asking you
.cpgThe text encodingAccented names may be garbled

The converter names any missing part rather than guessing silently.

Coordinate systems

The Information System takes WGS 84 in decimal degrees only, and it does not convert anything for you (GeoJSON File Description, Introduction). A shapefile in a UTM zone or a national grid is converted using its .prj. When there is no .prj, we only guess when exactly one WGS 84 UTM zone puts every plot inside the declared country; otherwise you pick from the likely systems, or search all 6,983 in the EPSG dataset by code or name. See UTM to WGS 84 for how to recognise each case.

Attribute names

Shapefile field names are limited to ten characters and are often abbreviated: PROD_NAME, CNTRY, AREA_HA. The Information System reads exactly ProducerName, ProducerCountry, ProductionPlace and Area, and ignores everything else (GeoJSON File Description, Common errors 9). The converter recognises common names in English, French, Spanish, Portuguese and Indonesian, and lists every mapping it made. Areas in square metres are converted to hectares, and the conversion is noted.

Sources

Last verified against these sources on .