Using lidar change detection to support the flooding recovery efforts in British Columbia

In November of 2021, southwestern British Columbia, Canada and northwestern Washington State were affected by a series of atmospheric rivers that caused widespread geohazards and destruction of critical infrastructure. This weather event resulted in massive precipitation leading to flooding, landslides, and debris slides that impacted many communities. Highways, pipelines, energy transmission lines, and railways all experienced damage and were inoperable – at the date of writing, some still are.

In the immediate aftermath of the event, BGC worked collaboratively with our clients to develop an understanding of the damage and chart a path to recovery. One of the many techniques we deployed was regional scale three-dimensional lidar change detection. Numerical processing can be used to quickly identify and visualize areas of topographic change where multiple lidar datasets are available for the same areas. In the case of the British Columbia atmospheric river events, BGC used airborne lidar scanning change detection to find and quantify the resulting geohazard activity, which took the form of landslides, flooding, bank erosion, and debris slides.

Working closely with our partners at McElhanney, we collected over 500 square kilometres of airborne lidar scanning data between Hope, BC and Merritt, BC. The post- atmospheric rivers data was compared to earlier datasets available from prior work for clients in the area. BGC was able to deliver digital change detection results within hours of receiving the lidar data from McElhanney using our patent processing method (patent has been allowed and is currently in the process of being granted). Results were immediately available to our clients and their partners through Cambio, our secure online platform, to support in recovery efforts. The resulting data was used to identify impacts on assets, prioritize field inspections, develop new designs, and understand future risks.

In the past year we have processed over 50,000 square kilometres of lidar change detection data, serving up tens of billions of lidar change detection points in Cambio to clients globally. We are proud that this work has been able to rapidly deliver high-value information used to save lives, reduce costs, and protect the environment.

Matthew Lato, PD.D., Eng., P.Eng. (AB, BC, ON, SK)

Innovation Lead

Matthew Lato is a Senior Engineer at BGC. His technical expertise is in the application of 3-dimensional remote sensing, specifically LiDAR and photogrammetry, for geotechnical mapping, change detection monitoring, and stability assessment and geohazard risk management. He is the lead author of the Site Investigation, Analysis, Monitoring and Treatment chapter of the Canadian Technical Guidelines and Best Practices related to Landslides, the recipient of the 2018 Canadian Geotechnical Colloquium Award, and an author or co-author of over 31 journal papers and 90 conference papers.