The Degree of Urbanization classifies every square kilometre of a site's territory into one of eight settlement categories defined by the EU GHSL-SMOD (Global Human Settlement Layer -- Settlement Model). The classification ranges from water bodies and very low-density rural land to dense urban clusters and urban centres, providing a complete picture of how built-up the site is and how this composition has evolved across five-year epochs from 1975 to 2030.
Urbanization is one of the primary global drivers of biodiversity loss. Converting natural habitats into artificial surfaces reduces ecological connectivity, fragments ecosystems, and disrupts local hydrological and climatic cycles. Monitoring the degree of urbanization allows organisations to understand anthropogenic pressure on natural habitats and to plan sustainable land use strategies.
| SMOD Class | Code | Description |
|---|---|---|
| Water | 10 | Water bodies |
| Very low-density rural | 11 | Near-natural or agricultural with minimal human presence |
| Low-density rural | 12 | Rural with low population pressure |
| Rural cluster | 13 | Small rural settlements |
| Suburban or peri-urban | 21 | Peri-urban fringe areas |
| Semi-dense urban cluster | 22 | Moderate urban development |
| Dense urban cluster | 23 | Dense urban development |
| Urban centre | 30 | Highest density -- maximum anthropogenic pressure |
The indicator is based on the GHSL-SMOD classification produced by the Joint Research Centre (JRC) of the European Commission. The settlement model integrates satellite land cover data with population census data to assign each 1 km squared grid cell one of the eight SMOD classes.
where the eight class percentages at any given epoch sum to 100%
A water correction is applied: pixels classified as water in the ESA Land Cover dataset are overridden to the SMOD Water class before aggregation.
Data are sourced from GHSL GHS-SMOD V2.0 (P2023A) at 1,000 m resolution, covering 12 five-year epochs from 1975 to 2030.
Note: This indicator is inverted -- lower urbanization levels (more rural, more natural) indicate better conditions for biodiversity. Higher SMOD class values (dense urban, urban centre) are ecologically negative.
Line Chart. A multi-series line chart with 8 simultaneous lines, one for each SMOD settlement class.
Purpose: How has the settlement composition of the site evolved across epochs from 1975 to 2030, and how does it compare to the surrounding control area?
Description: The chart shows the percentage of site area falling into each of the 8 SMOD classes at each 5-year epoch. The X-axis shows years (1975--2030); the Y-axis shows percentage (0--100%). Each SMOD class has a fixed color line. Future epochs (2025, 2030) are shown with dashed lines. An interactive legend below the chart allows toggling individual class lines on and off. A Site / Control Area toggle switches between the site's own data and the surrounding reference area.
How it's calculated: For each epoch, the percentage of site area in each SMOD class is computed from the GHSL-SMOD raster.
Note: This indicator is inverted -- lower urbanization (rural classes dominating, lines near 100%) indicates better ecological conditions. A rising "Urban centre" or "Dense urban" line over time signals increasing pressure on the site.
Legend:
| SMOD Class | Label | Color |
|---|---|---|
| 10 | Water | ■ #7ab6f5 |
| 11 | Very low-density rural areas | ■ #cdf57a |
| 12 | Low-density rural areas | ■ #abcd66 |
| 13 | Rural agglomeration | ■ #375623 |
| 21 | Suburban or peri-urban | ■ #ffff00 |
| 22 | Semi-dense urban agglomeration | ■ #a87000 |
| 23 | Dense urban agglomeration | ■ #732600 |
| 30 | Urban centre | ■ #ff0000 |
No A--E quality scale exists for this KPI. The classification is categorical, not ranked.
Interpretation example:
If the "Very low-density rural areas" line (light green) sits at 70% across all epochs while the "Urban centre" line (red) stays below 2%, the site is predominantly natural and rural -- excellent for biodiversity. If the "Dense urban agglomeration" line (dark brown) rises from 5% in 1975 to 35% in 2020, the site has experienced significant urbanization over the monitoring period, representing increasing ecological pressure.
Map Layer. An interactive discrete-color map overlay showing the SMOD classification for a selected epoch.
Purpose: Which parts of this site and surrounding landscape are most urbanized, and how does settlement distribution vary spatially?
Description: The layer appears in the map view under the "Urbanization Status" category. Up to 12 map tiles can be generated (one per epoch). The layer chip shows the generation timestamp and a badge with the number of generated maps. When selected, the map legend title shows "Degree of Urbanization" with the selected date.
How it's calculated: The discrete 8-class colormap is applied to the GHSL-SMOD raster at the selected epoch. No continuous interpolation -- each pixel shows its exact SMOD class color.
Note: This indicator is inverted -- pixels in the Water and Very low-density rural classes (blues and light greens) represent the best ecological conditions; pixels in Dense urban and Urban centre classes (dark brown and red) represent the worst.
Legend:
| Class | Color | Meaning |
|---|---|---|
| Water | ■ #7ab6f5 | Water bodies |
| Very low-density rural areas | ■ #cdf57a | Near-natural / agricultural with minimal human presence |
| Low-density rural areas | ■ #abcd66 | Rural with low pressure |
| Rural agglomeration | ■ #375623 | Small rural settlements |
| Suburban or peri-urban | ■ #ffff00 | Peri-urban fringe areas |
| Semi-dense urban agglomeration | ■ #a87000 | Moderate urban development |
| Dense urban agglomeration | ■ #732600 | Dense urban development |
| Urban centre | ■ #ff0000 | Highest density -- maximum anthropogenic pressure |
Interpretation example:
If a site map shows a large green-dominated area (classes 11--12) with only a small red patch (class 30) in one corner, the site is predominantly rural with a localized urban core -- the red area should be watched for expansion in future epochs.
Detail Card. A breakdown panel showing the SMOD class distribution in hectares, grouped by type (Water, Rural areas, Urban areas), for the selected epoch.
Purpose: How much area belongs to each SMOD class at the selected epoch?
Description: The panel title shows "Degree of Urbanization". Each class is listed with its name and area in hectares. Classes are grouped into three types: Water, Rural areas, and Urban areas. A total area summary is also shown.
How it's calculated: Area values are derived from the GHSL-SMOD raster classification at the selected epoch, with per-class areas calculated in metric projection for accurate surface measurement.
Note: This indicator is inverted -- a high proportion of rural or water hectares indicates better ecological conditions; a high urban hectare count indicates greater pressure.
Interpretation example:
If the panel shows 7,200 ha in "Very low-density rural areas" and only 2,000 ha in "Urban centre", the site is overwhelmingly rural. A dominant "Urban centre" value would signal critical ecological pressure.
| Source | Provider | Coverage | Resolution | Period |
|---|---|---|---|---|
| GHSL GHS-SMOD V2.0 (P2023A) | JRC / European Commission | Global | 1,000 m | 1975--2030 (5-year epochs) |
Available epochs: 1975, 1980, 1985, 1990, 1995, 2000, 2005, 2010, 2015, 2020, 2025, 2030 (12 total). The 2025 and 2030 epochs are demographic projections, not observations.
The GHSL-SMOD classification integrates satellite land cover data with population census data to assign each 1 km squared grid cell one of the eight SMOD classes. The settlement model uses a hierarchical decision tree that considers both built-up surface density and population density thresholds.
A water correction is applied before aggregation: pixels classified as water in the ESA Land Cover dataset are overridden to the SMOD Water class (code 10), ensuring consistent treatment of water bodies across the classification.
For each site polygon and epoch, the percentage of area in each SMOD class is computed from the raster. Per-class area values are stored in hectares. The eight class percentages at any given epoch always sum to 100%.
Future projections for the 2025 and 2030 epochs are based on demographic population models rather than satellite observations. These appear as dashed lines on the trend chart to signal their modelled nature.