Canopy Clearance: A Customized Solution

True North | Winter 2020

Each spring the Moncton Parks Operations was required to provide a minimum tree canopy clearance of thirteen feet over municipal roadways and eight feet over the sidewalks. To do this they would attach a measuring stick to a vehicle and everywhere it hit the branches they would get out their pruning equipment and make the necessary adjustments. This was neither efficient nor reliable. What they really desired was the ability to map the location of the trees and to capture the location of all of the branches so they could determine the ones that were approaching the minimum height requirement. This would allow them to plan and anticipate maintenance resources that would be required.

The idea they came up with was to attach some kind of measurement solution to the Parks’ street cleaners since they were tasked with clearing the streets of winter debris anyway prior to the tree trimming exercise, thereby killing two birds with one stone. But how?

The Moncton Parks Operations management contacted Cansel and asked if we could devise a system to meet the above requirements. The configuration of hardware and software that Cansel developed consisted of a laser sensor, a GNSS receiver, a tablet, and an application called Low Hanging Branch Detector.

With Cansel’ s solution in hand the street sweepers automatically collect tree location and canopy data while the vehicle is cleaning the street. Once the vehicle is back in the office the data can be transferred to any GIS software where they can apply filters based on their clearance requirements. Once this is compiled and with coordinates data in hand, an arborist can return directly to the streets where the trees need to be trimmed.

The efficiencies we created for Moncton Parks is significant. Previously, the data collection took two dedicated resources to drive and map the city. Today the data collected is digitally recorded into the GIS and tree trimming is optimally routed. Since the data is collected at a high level of accuracy, branches can be individually removed to meet the clearances versus a large scale cut of all trees, thus maintaining the curb appeal in these mature neighborhoods.

Image shows the data that has been collected in the area and later has been classified based on different branches heights; for instance, under 13 feet is a red zone which means they have to trim the trees as soon as possible, 13-14 feet is a yellow zone which means they have to keep an eye on.

Ali Mousavi, Ph.D. | Mapping and GIS Lead
Professional Services Group