Mapping urban ventilation corridors and assessing their impact upon the cooling effect of greening solutions

Over the past decades, climate change has become among the top issues challenging cities worldwide, endangering the urban infrastructures and threatening the health of millions of people. Hence, climate action, both in terms of mitigation and adaptation to climate change, has become a priority for urban planning. This work introduces an example of the promising role that spatial analysis and statistical modelling, employing Geographical Information Systems (GIS) and freely available satellite and land-based data, can provide in supporting urban climate design and policymaking. In particular, this study puts special attention on the Urban Heat Island (UHI) phenomenon. Here, we first introduce a simple, but effective morphological-based approach for mapping potential ventilation corridors across cities of uniform built-up structure, as a common UHI mitigation measure. Then, we propose a methodology for assessing the relative role of these corridors in maximizing the impacts of green solutions upon lowering high temperature. Results show that even under very calm wind conditions, there is still an opportunity for maximizing the benefits of greening measures on the urban climate. Also, it has been demonstrated that green ventilation corridors are more effective during night-time when the UHI effect is peaked. The research findings are very promising, especially for cities where wind is a marginal potentiality.