Developing an Automated City of Whittlesea Urban Tree Canopy Inventory Using Airborne LiDAR and Aerial Imagery

Abstract

The City of Whittlesea is in Melbourne’s north and is one of the largest municipalities in metropolitan Melbourne. The council GIS team using current aerial photos from 2017 and LiDAR (“LiDAR” stands for Light Detection and Ranging) point clouds 2009 products to identify trends in urban tree canopy cover in the established suburbs of the municipality between 2009 and 2017. The tree canopy coverage was calculated for residential properties, road reservations, public land and park sites within urban parts of Bundoora, Epping, Lalor, Mill Park, Thomastown, and South Morang. From the total project area of approximately 3499 hectares a test site was selected based on an extension of one of the LIDAR data tiles (e325n5828). This project investigates only 6 meters and higher tree canopy cover within the project area. The objectives of the project were to establish a methodology to calculate the urban tree canopy coverage from LiDAR 2009 data, that can be replicated in future calculations. The calculated urban tree canopy coverage from LiDAR 2009 data is 9%, compared to 8% coverage in 2017, based on aerial photography. This estimate was compared to similar Local Governance Areas that range from 12% to 40%. A key to planning and managing urban tree canopy is first to understand the quantity, quality, tree density and distribution of the resource across the landscape. Tree inventories and urban tree canopy analyses comprise an assortment of tools, technologies, and procedures that help us understand the structure and function of our urban tree canopy. The data and information gleaned from urban tree canopy assessments enable resource professionals and policymakers to make informed decisions about ordinances, housing diversity strategy, and budgeting, future tree planting programs and reduce urban heat islands.