Effects of 2019 severe flooding on Toronto Island Vegetation communities

Despite many infrastructure initiatives, Greater Toronto and much of Ontario remain vulnerable to severe storms and flooding. In 2019, the water level in Lake Ontario reached a historical high causing significant damage to ecologically significant plant communities on the Toronto Islands. Since the flood occurred, several reports have outlined damages to homes and build surfaces; however, the effect of flooding on the natural environment has received limited investigated. This study focuses on identifying the impacts of the flood on natural spaces using Sentinel-2a data to create a: Normalized Difference Vegetation Index, Tasseled-Cap Transformation, and Disturbance Index. Results of this study indicate that vegetation on Gibraltar Point and Ward's Island experienced the greatest amount of flooding-related damage. Light Detection and Ranging data, along with fieldwork and expert consultation, was used to identify impacted plant species within the flood-affected vegetation communities. Keywords: GIS, Toronto Island, Ecological Disturbances, Flooding, 2019, Lake Ontario, LiDaR, Sentinel-2a, Disturbance Index, NDVI, Vegetation Communities