Tree removal detection in Santa Monica
PROTECTING URBAN CANOPY COVER
Trees matter, and the protection of our urban forest is in everyone’s interest. One way to protect urban trees is through tree preservation ordinances. These laws guide the preservation, protection, maintenance, and replacement of a community's trees. To protect trees from unnecessary destruction, their removal must be permitted.
The City of Santa Monica, like many other cities, struggle to stay informed of illegal tree removals, because several protected trees are often hidden in yards and on private property. To show the City of Santa Monica how we might spot tree removals, we started with a small part around the UCLA Medical Center, as this region had a high density of tree removals.
In the top right corner, you can play around with the different layers and switch them on and off. We used WorldView 3/4 imagery from 2017 and 2019 and applied a classifier and segmentation on it. If you look at the trees removed on 16th Street (next to UCLA Med Center) you can see a clear distinction between 2017 and 2019. Further down 16th Street, between Arizona Avenue and Santa Monica Blvd, the distinction is less clear. Regardless, we think this is a very promising result for the short turnaround time of this demo and the more basic algorithms used at this time.
Should we continue, we would improve the accuracy by using our more advanced algorithms and by using more frequent imagery. In the long(er) term, we'd also love to experiment with an alert detection system: in essence, a completely automated product that would send an email/SMS/notification to the tree ordinance/enforcement officer. We believe it would be highly valuable to the municipality with potential for major cost savings and important addition to the Green City Watch Platform.
TOOLS & SERVICES:
Very High Resolution (VHR) satellite imagery
Urban tree canopy cover