Tree canopy cover atlas

The canopy cover atlas provides information on the canopy cover of the Helsinki Metropolitan Area, i.e. the percentage of the area of a city, district or block covered by trees. The atlas highlights that the amount of trees varies greatly by district in the Helsinki Metropolitan Area. Data and methods for canopy cover analysis Canopy cover is a sustainability indicator of green infrastructure that combines many climate and well-being benefits. The importance of the indicator has increased with the European Commission’s Nature Restoration Law, as the regulation requires urban areas to monitor and develop canopy cover. The calculation of canopy cover is based on various spatial data sets or laser-scanned point cloud data. Since there are differences in the accuracy of the data sets, the results of the canopy cover calculation may also vary slightly. Differences also arise from the height of vegetation included in the canopy cover calculation. Some canopy cover calculations use vegetation over 2 meters as a criterion, while others include vegetation over 5 meters, for example. The source data and methods used in this atlas are described below. Materials used The work utilized the administrative regional divisions data (NLS 2023) of the National Land Survey of Finland to define municipal boundaries, as well as data available from the open WFS spatial data interfaces maintained by the municipalities of the Helsinki Metropolitan Area to create a hierarchical regional division data describing the variation in canopy cover. The land cover data produced by the Helsinki Region Environmental Services based on laser scanning from 2024 (HSY, 2025) was used as the canopy cover data. The data is in vector format and the trees are classified by height into 2-10 m, 10-15 m, 15-20 m and over 20 m tall trees. The nominal resolution of the data is 3*3 meters. Trees over 2 meters tall were included in the calculation. Methods HSY’s land cover data was rasterized according to the 3*3 meter base raster corresponding to the nominal resolution. After this, the relative shares of canopy cover per area unit were calculated by height class of the stand. These were combined to describe the total canopy cover of the stand. References Espoon kaupunki (2025). Espoon kaupunginosajako. Ladattu Espoon kaupungin WFS-rajapinnalta osoitteesta https://kartat.espoo.fi/teklaogcweb/wfs.ashx (luettu 28.3.2025). Espoon kaupunki (2025). Espoon korttelit. Ladattu Espoon kaupungin WFS-rajapinnalta osoitteesta https://kartat.espoo.fi/teklaogcweb/wfs.ashx (luettu 28.3.2025). Helsingin kaupunki (2025). Helsingin kaupunginosajako. Ladattu Helsingin kaupungin WFS-rajapinnalta osoitteesta. https://kartta.hel.fi/ws/geoserver/avoindata/wfs (luettu 28.3.2025). Helsingin kaupunki (2025). Helsingin pienalueet. Ladattu Helsingin kaupungin WFS-rajapinnalta osoitteesta. https://kartta.hel.fi/ws/geoserver/avoindata/wfs (luettu 28.3.2025). Helsingin kaupunki (2025). Helsingin korttelit. Ladattu Helsingin kaupungin WFS-rajapinnalta osoitteesta. https://kartta.hel.fi/ws/geoserver/avoindata/wfs (luettu 28.3.2025). Helsingin kaupunki (2025). Helsingin kaavayksiköt. Ladattu Helsingin kaupungin WFS-rajapinnalta osoitteesta. https://kartta.hel.fi/ws/geoserver/avoindata/wfs (luettu 28.3.2025).