VIRTUAL Barcelona Livable Cities
Abstract
Green roofs are elevated gardens constructed on building rooftops. Aside from their aesthetic appeal, they are highly functional living structures that provide important ecosystem services in densely populated urban areas. These benefits include stormwater management, mitigation of the urban heat island effect, air quality improvement, urban food production, and enhanced biodiversity. Cities around the world have introduced policies, incentives, or both to promote green roof installations on buildings. However, recent studies primarily focused on quantifying ecosystem services of green roofs. Opportunities remain to investigate the spatial-temporal distributions of green roofs to monitor their development and identify local neighbourhoods with potential for green roof implementation. By utilizing a combination of very high-resolution aerial images, building footprints and normalized difference vegetation index (NVDI), this study presents a method to detect the presence and changes of green roofs for selected regions in Toronto within a 10-year period. The result showed a high concentration of green roofs in the Toronto Centre area compared to the rest of the areas examined. In the 2013-2023 period examined, a larger portion of green roofs were found to be constructed during 2013-2018. This signifies a decline in new green roof construction in recent years. Green roofs are vital to advancing urban sustainability and mitigating environmental challenges. This study provides valuable insights into the current state of green roof distribution in Toronto and presents a method that could be applied to visualizing and reviewing the state of green roofs in other parts of the world.
Frances Leung is a doctoral researcher in the Department of Geography, Geomatics, and Environment at the University of Toronto. Her research focuses on understanding the roles that urban and suburban greenspaces play in promoting sustainability and biodiversity amid climate change. Using remote sensing techniques, she investigates the spatial-temporal changes of vegetation and land use for greenspaces such as parks, gardens, and green roofs. Through this work, she aims to uncover insights that will guide the creation of more sustainable, adaptable, and resilient environments.
Dr. Yuhong He is a Professor in the Department of Geography, Geomatics and Environment at the University of Toronto. Her research employs remote sensing, machine learning, and ecosystem modeling to study changes in natural (grasslands, forests, wetlands) or managed (farmlands and urban) systems. Dr. He has mobilized multidisciplinary researchers for the common goals of understanding how human activities and global changes affect environments and discovering how to make our natural/built environments healthier, more resilient, and adaptable. With over 100 peer-reviewed journal articles and 120 conference papers, Dr. He and her team have made substantial contributions to the remote sensing field.
Adam Martin is an ecologist in the Centre for Critical Development Studies and the Department of Physical and Environmental Sciences. He is interested in how differences in the morphological, chemical, and physical characteristics of plants – or their functional traits – influence the structure and function of agroecosystems. He is particularly interested in understanding how differences in leaf functional traits, both between and within crops, influence agroecosystem resilience and resistance to global change. Adam maintains active research on the carbon dynamics of tropical forests throughout Central America, the Caribbean, and South-east Asia. Adam has published in journals including PLoS ONE, AoB Plants, and Forests, as well as leading plant ecology journals such as New Phytologist and Tree Physiology.