Distance to Small Gardens

Urbanizationv03.00 credits/per_km2

Responsible:Niccolò Calandri

Distance to Small Gardens

Overview

Distance to small gardens measures the Euclidean distance (in metres) from every point in the study area to the nearest garden or neighbourhood green space, defined as a contiguous green area of at least 0.04 hectares (400 m²). This indicator provides information on fine-grained accessibility to urban green spaces, including small spaces such as residential gardens, community allotments and small playgrounds.

Unlike Distance to Green (which considers all green areas) and Distance to Parks (0.5 ha threshold), this indicator captures the green micro-structure of the urban fabric: the small green spaces that ensure daily contact with nature for residents. Scientific research shows that even small green spaces (< 0.5 ha) contribute significantly to physical and mental well-being and stress reduction (Peschardt et al., 2012).

The ANGSt standard (Accessible Natural Greenspace Standard, Natural England, 2010) recommends that every resident should have access to a green space within 300 m of their home. The WHO further specifies that small but well-distributed green spaces can have a positive impact on public health (WHO, 2016).

Calculation Methodology

The indicator calculates the Euclidean distance from every point in the polygon to the nearest small garden:

Data source — ESA WorldCover 2021 (10 m), high-resolution global land cover map
Green classes — the following vegetation cover classes are considered:
- 10 — Tree cover (forests and tree coverage)
- 20 — Shrubland
- 30 — Grassland (meadows and pastures)
- 90 — Herbaceous wetland
- 95 — Mangroves
- 100 — Moss and lichen
Connected component analysis — scipy.ndimage.label with 8-connectivity to identify contiguous green patches
Area filtering — patches with area less than 0.04 hectares (400 m²) are excluded, keeping only significant gardens and green spaces
Distance Transform — scipy.ndimage.distance_transform_edt to compute Euclidean distance from each pixel to the nearest garden
Conversion — values converted to metres based on raster resolution
Buffer — 1000 m buffer around the polygon to handle edge effects
Aggregation — calculation of mean, median and percentile distribution within the polygon

Unit: metres (m)

Data Sources

Code	Name	Provider	Resolution	Availability
`WRD_ESWCV_99`	ESA WorldCover	ESA / Vito	10 m	2020 — 2021
`WRD_IMPBS_99`	Impact Observatory	Impact Observatory	10 m	2017 — present
`WRD_S2SCL_99`	Sentinel-2 SCL	ESA/Copernicus	20 m	2017 — present
`WRD_GDYXX_99`	Google Dynamic World	Google	10 m	continuous
`WRD_OSMXX_99`	OpenStreetMap	OpenStreetMap Foundation	vector	continuous
`WRD_BIODL_99`	Biodiversa LC	Biodiversa+	10 m	2020 — present
`WRD_CLCBK_99`	CLC Backbone	EEA	100 m	2018
`WRD_CRINE_99`	Corine Land Cover	EEA	100 m	1990 — 2018
`WRD_DOMLT_99`	Dominant Leaf Type	Copernicus Land	100 m	2015 — present
`WRD_EUCRP_99`	European Crop Map	JRC	10 m	2018 — present

Quality Range and Levels

Indicator	Unit	Range	Inverted
`distance_to_small_gardens`	m	[0, 150, 300, 500, 1000, 2000]	Yes

Inverted = Yes: a shorter distance is better, as it indicates greater proximity to small gardens and better access to neighbourhood green spaces.

Thresholds follow the ANGSt standard (Natural England, 2010):

Level	`distance_to_small_gardens`	Interpretation
E	> 1000 m	Very poor access to gardens
D	500 – 1000 m	Insufficient access to gardens
C	300 – 500 m	Moderate access to gardens
B	150 – 300 m	Good access to gardens
A	0 – 150 m	Excellent access to gardens

Technical Notes

Distance to Small Gardens maps must be generated before computation
The reader can also use the NAA layer from the database if available for the site
The 0.04 ha (400 m²) threshold corresponds approximately to a 20×20 m area, a typical size for a residential garden or small playground
The 1000 m buffer reduces artefacts at the polygon boundary
Green classes include wetlands and mangroves, which may not be physically accessible

References

Natural England (2010). "Nature Nearby: Accessible Natural Greenspace Guidance". Natural England Commissioned Report NECR017. (ANGSt standard)
WHO (2016). "Urban green spaces and health: A review of evidence". World Health Organization, Regional Office for Europe, Copenhagen.
Peschardt, K.K., Schipperijn, J. & Stigsdotter, U.K. (2012). "Use of Small Public Urban Green Spaces (SPUGS)". Urban Forestry & Urban Greening, 11(3), 235-244.
Zanaga, D. et al. (2022). "ESA WorldCover 10 m 2021 v200". Zenodo. https://doi.org/10.5281/zenodo.7254221

Quality Ranges and Levels

distance_to_small_gardens

(m)

ACritical

BLow

CModerate

DGood

EExcellent

0 → 149.99

150 → 299.99

300 → 499.99

500 → 999.99

1000 → 2000

Critical0 – 149.99

Low150 – 299.99

Moderate300 – 499.99

Good500 – 999.99

Excellent1000 – 2000

Data Sources & References

Sources

WRD_ESAXX_21WRD_IOAXX_99WRD_SCLXX_99WRD_GDYXX_99WRD_OSMXX_99WRD_BDVXX_99EUR_CBKXX_21EUR_CLCXX_18EUR_DLTXX_18EUR_CROXX_22

Methodology

The Distance to Small Gardens map calculates the Euclidean distance from every point to the nearest small garden or neighbourhood green space, defined as a green area of at least 0.04 hectares (400 m²). The calculation uses ESA WorldCover 2021 classification, identifying green classes: 10 (Tree cover), 20 (Shrubland), 30 (Grassland), 90 (Herbaceous wetland), 95 (Mangroves), 100 (Moss and lichen). Connected component analysis (scipy.ndimage.label) with 8-connectivity identifies contiguous green patches. Patches smaller than 0.04 hectares (400 m²) are filtered out. Euclidean distance (scipy.ndimage.distance_transform_edt) is calculated on the resulting mask and converted to metres. A 1000 m buffer is applied to avoid edge effects. Classification into 5 levels: 1-Excellent (0-150m), 2-Good (150-300m), 3-Moderate (300-500m), 4-Bad (500-1000m), 5-Very Bad (>1000m).