One of the central parts of the BIG project is the Map of Trees. This map can help us identify benefits from a tree, for example how trees can influence the health of individuals or determine attractiveness for a certain area. It can also show us how they may contribute to a road being walkable or attractive for bypassers, with additional analysis. It is also a big part of modelling and analyzing the ecosystem services that the project will produce for the entire city of Gävle.
With remote sensing and GIS modelling, researcher Nancy Joy Lim can extract the position of each tree automatically, instead of mapping them one by one. The tree data will be derived from point cloud data provided by Lantmäteriet. A point cloud data is a set of millions of data points in space, where each point can represent a 3D object, in this case an individual tree. With this information, the project can determine the position of each tree, with a certain error margin, as well as estimate its height and visualize its canopies.
At the moment we are evaluating the results for our test site in Gävle and will have them ready some time next year, says Nancy Joy Lim.
– When we have finished this model, we can do this anywhere in Sweden in the future, not just in Gävle.