Urban Tree Canopy Assessment Using Geospatial Technologies: A Case Study of the Town of Lincoln, Ontario

Abstract

Urban trees provide important benefits to communities, from mitigating stormwater to improved air quality. Municipalities across Ontario encounter a decline in their urban tree canopy (UTC). UTC assessment is essential for the management of urban trees, especially in the context of climate change. However, quantifying the canopy remains a challenge, given that tree crowns are difficult to assess from the ground. Geospatial technologies provide a suitable alternative to costly, ground-based assessments. Still, they typically require a significant investment in resources, including technical expertise and equipment. For many small- and medium-sized municipalities facing the realities of climate change, these investments are cost-prohibitive. This study aimed to assess the UTC within the Town of Lincoln, Ontario, using geospatial technologies. The first objective was to estimate canopy cover and distribution using image classification as the main approach. The second objective was to assess the proficiency of a low-cost method based on image interpretation (i.e., i-Tree Canopy) to calculate canopy cover compared to the main approach. The third objective was to examine the possibility of using the canopy goal designated by the Niagara Official Plan as a standard canopy goal. This research study produced three main results. First, the image classification indicated that the tree canopy covers 21% of the Town. Second, this study demonstrated that the results from the main approach are similar to those obtained from i-Tree Canopy. Given the similarity between these approaches, this study concluded that the lower-cost i-Tree Canopy method could be combined with other methods to prepare accurate and affordable canopy assessments for resource-limited municipalities. Finally, this study concluded that canopy goals should account for local Urban Tree Canopy Assessment Using Geospatial Technologies differences based on geographic location. This study makes a valuable contribution to the literature as it informs management of canopy resources in communities with limited resources. Outcomes from this study can also better inform tree-canopy goals and policies with a cost-effective method that requires minimal expertise. The ability to conduct UTC assessment in smaller communities is critical in mitigating the impacts of climate change facing most of these communities.