Getting started
Sample data
Ready-to-use datasets for testing the plugin — the same sources used in the original research for Portugal Continental.
Download the datasets below and load them into QGIS to follow along with the documented workflow. All sources are freely available from official providers.
CRS requirement — projected metric system only. All layers must be in a projected CRS whose units are metres (e.g. EPSG:3763 for Portugal, a UTM zone for other regions). A geographic CRS such as EPSG:4326 (degrees) causes silently wrong results — the cost model and all distance/area calculations assume metres. If your data is in a geographic CRS, reproject it before loading it into the plugin.
The plugin has only been tested extensively with EPSG:3763 (PT-TM06 / Portugal Continental). Other projected metric CRS should work, but no systematic validation has been done yet outside that context.
Land use
Plugin tab: Land Use
The Carta de Ocupação do Solo Conjuntural 2024 – Pré-Verão (COSc 2024) is an annual raster land use/land cover map at 10 m spatial resolution, produced from Sentinel-2 imagery by the Direção-Geral do Território (DGT). It is provided natively in EPSG:3763, so no reprojection is needed for Portugal.
Once loaded, click Populate according to COMET in the Land Use tab to automatically assign cost factors to each COSc class — no manual configuration required.
Protected areas are not auto-populated. COMET defines a protected-areas category with a cost factor of 10, but Portugal’s COSc map does not have a dedicated protected-areas class — so Populate according to COMET leaves it unset. See COSc to COMET mapping for details. If you want to follow the COMET approach and account for protected areas, you can overlay a separate protected-areas layer (e.g. from ICNF), reclassify the pixels within those zones to a new class, and assign a cost manually in the Land Use tab — Populate according to COMET will not touch it.
Digital Elevation Model
Plugin tab: Slope
A DEM is needed to derive the terrain slope cost surface. The plugin’s Slope tab computes slope in percent (%) from the DEM using QGIS’s native slope algorithm.
The FCUP DEM page hosts several DEMs for Portugal Continental (SRTM, ASTER, ALOS-AW3D30, TanDEM-X). Each DEM is available in two variants: geographic (EPSG:4326, pixel size ≈ 1 arcsecond) and projected metric (EPSG:3763, GSD=25 m). Download the EPSG:3763 variant — the geographic one uses degrees as units and cannot be used directly with the plugin.
The one used in the original research is SRTM-DEM EPSG:3763, GSD=25m: clipped to Portugal Continental and resampled to 25 m in Portugal’s national CRS (EPSG:3763). No reprojection needed.
Already have a slope raster? If you have a pre-computed slope layer in percent (%), you can skip DEM import entirely and load it directly into the Slope Costs step. Slope rasters in degrees are not directly compatible and must be converted to percent before use.
Crossings
Plugin tab: Crossings
Two vector layers are needed — roads and railways. Download both and, if you want to process them together, use the Combine vectors helper in the Aux tab to merge them into a single layer before running the Crossings tab.
Roads
The national road network (motorways, primary, secondary, and other roads), published by Infraestruturas de Portugal, S.A.
Railways
The national railway network, published by Infraestruturas de Portugal, S.A.
High-speed rail does not currently exist in mainland Portugal and was not included in the original research.
Existing energy corridors
Plugin tab: Corridors
The SRUP layer from the Direção-Geral do Território (DGT) contains the onshore gas and oil pipeline network currently in operation in Portugal Continental. Following existing corridors reduces licensing costs and environmental impact.