Bluesky National Tree Map shows changing face of Sevenoaks

August 26, 2021  - By
Photo: Bluesky

Photo: Bluesky

A new map detailing the location, height and canopy for trees more than 3 meters in height is helping Sevenoaks District Council manage its iconic ancient trees and natural woodland.

Derived from Bluesky’s National Tree Map, which provides geospatial intelligence for more than 300 million trees across the United Kingdom, the data has already been used to create a district-wide map of tree cover, to create 3D visualizations to inform development decisions, and to support planning enforcement investigations.

Sevenoaks District Council originally purchased National Tree Map data from Bluesky in November 2019, and the data is widely used across the council with specific applications in planning.

Updated this year, the original and new tree-map layers are stored in the council’s GIS alongside multiple years of aerial photography, Ordnance Survey maps, data such as Ancient Woodland and Biodiversity Opportunities, and council data including Tree Preservation Orders and Planning Applications. The tree data is accessible to all staff via the council’s intranet mapping system GISMO (GIS Online).

The name Sevenoaks (the name given to the town and more recently to the district) dates to circa 800 A.D. and is thought to be derived from “Seouenaca,” the name given to a small chapel near seven oak trees. Records of these trees through the ages are sparse; it is not until the 19th century when a group of seven trees appears on an Ordnance Survey map.

The eponymous oak trees have been replaced many times over the years, including the planting of seven oaks to commemorate the coronation of Edward VII in 1902 and tree planting by personnel from the Canadian Air Force in 1947 in gratitude for being billeted in the town.

Bluesky’s National Tree Map is created using innovative algorithms and image processing techniques in combination with the most up-to-date and detailed aerial photography, terrain and surface height data, and color infrared imagery.

In addition to the three vector map layers — Crown Polygons, Idealised Crowns and Height Points — the Bluesky National Tree Map also includes an attribute table with unique identification for each crown feature, height attributes and area calculations.