Coordinate-Systems

The EU Deforestation Regulation applies from 30 December 2026. For operators placing timber, cocoa, coffee, palm oil, soy, cattle, and rubber on the EU market, compliance requires a Due Diligence Statement submitted through the TRACES NT system. That statement must include plot-level geolocation data — and the format specification is not flexible. TRACES accepts GeoJSON in WGS84 (EPSG:4326) with coordinates expressed as decimal degrees to at least six decimal places. Plots over 4 hectares require a complete boundary polygon. Plots under 4 hectares may be represented by a single point. ...

Data scientists encounter GIS when spatial data shows up in a project: a dataset with latitude/longitude columns, a shapefile from a government portal, a GeoJSON file someone dropped in the repo. The first few operations usually work. Then something breaks silently — a spatial join returns an empty DataFrame, a buffer produces geometry the size of a continent, or exported shapefiles arrive at the lab with every field name truncated. ...

TL;DR: If your QGIS buffer is the wrong size, your CRS is EPSG:4326 (degrees) — switch to a projected CRS (e.g. a local UTM zone) before buffering, or enable the Geodesic Distance option in the QGIS 3.28+ Buffer dialog. The QGIS Buffer tool has one requirement that is easy to miss: the distance you enter is in the unit of the layer’s CRS, not the unit of your project CRS, and not any intuitive real-world unit you might have in mind. ...

Drop a DXF file onto your GIS and the geometry lands in the middle of the ocean, rotated 90 degrees, scaled by 25.4. Or it lands in the right country but offset by a few hundred metres. Or it imports cleanly into QGIS but every feature ends up on a single layer called “0” with no attributes beyond the original AutoCAD entity type. This is not a bug you can fix with a setting. The CAD-GIS format gap is structural. DWG and DXF were designed for engineering drawings, not for placing things on Earth. GIS formats were designed for the opposite. The two worlds have different answers to three fundamental questions: where are these objects, what do we know about them, and how do they relate to each other? ...

A surveyor sends you a DWG with what looks like UTM coordinates. You open it in QGIS, the layer appears 100 kilometers from where you expected, and when you zoom to it the geometry is microscopic — a thirty-meter parcel that displays as a 30-millimeter sliver. You set the project CRS to the right UTM zone. Nothing changes. You build a custom CRS in metric units. Nothing changes. You ask the surveyor and they swear the file is correct in AutoCAD. ...