Where and how to cool? An idealized urban thermal security pattern model

Urban green infrastructure (UGI) has been recognized as a promising approach to mitigating urban heat island (UHI); however, most of the previous studies are case-based and explore the effects of the existent landscape and its spatial configuration on UHI mitigation rather than modeling an optimized spatial pattern. We aimed to transcend the existing research logic (from case studies to obtain the patterns of the cooling effect of UGI, then propose implications for UHI mitigation) and established a hypothetical idealized urban thermal security pattern model (TSPurban). Based on two basic concepts deduced from the physical property of UGI—(threshold) size and cooling distance, as well as the simplifying assumptions we defined. Then, three proposed conceptual UGI types (ecological, efficient, and elementary—3E) and subtypes were used to frame the model. We deduced that the idealized TSPurban model conforms to a hierarchical hexagonal structure in theory and it can be calculated and applied, although it generally cannot be seen in the real world. The idealized TSPurban model can help us better-understanding UGI cooling effects when considering climate adaption planning and decision-making; it also serves as a novel pathway to study the cooling effects of UGI and mitigate the UHI effect.