Built Heritage Preservation and Climate Change Adaptation in Historic Cities: Facing Challenges Posed by Nature-Based Solutions

Historic centres are extremely complex parts of contemporary cities, particularly from morphological, architectural, and cultural points of view, where a significant proportion of the land area may be occupied by built heritage sites that require protection and conservation. These urban contexts are also characterised by scarce green and public open spaces endowment, a high proportion of private property, and high levels of natural risk exposure. From a climate change adaptation perspective, Nature-based Solutions (NbS) have emerged as measures to manage urban ecosystems to address environmental and societal challenges. To overcome the conflicting objectives of climate change adaptation and built heritage preservation, this study proposes a three-step methodology applied to the historic centre of Catania (Italy): (i) Land-Use/Landownership and Land Cover/Maintenance and Quality analyses; (ii) Land Transformability Assessment; (iii) Land Transformation Scenarios Assessment. According to this methodology, five Land Transformation Scenarios have been drawn up: (1) NbS full installation; (2) NbS installation with some limitations; (3) NbS installation after re-arrangement; (4) NbS installation strongly limited; (5) NbS installation not viable. This approach allowed us to identify the most feasible and suitable buildings and open spaces, while distinguishing public and private properties, to implement a more comprehensive integration of NbS and built heritage preservation in historic cities for mutual benefits.