Urban heat island phenomenon and ecological indicators: The case study of the historical town center of Aversa (Ce)

Climate change has reinforced the importance of the green component, especially in its thermal mitigation functions. The theme of the renaturalization of the city [1], through initiatives of structural integration of greenery with the anthropized environment, represents an important objective of urban and territorial planning. It is necessary to assign to green, functions capable of satisfying real needs; in fact, if the Grey Infrastructures constitute the built capital of our cities and are necessary for the economic development of a territory, the Green Infrastructures [2], represent its natural capital and are necessary to guarantee environmental sustainability [3]. In the case of the compact city, where the urban form is largely established, it is difficult to create significant green spaces. Green infrastructure represents a new approach to the problem: street trees, green construction along railway lines, green roofs and facades are seen as solutions that are easy to implement and suitable for building links with nearest green spaces. There is therefore a need in the drafting of urban planning instruments to plan actions aimed at counteracting the effects of climate change. To this end, it is important to analyze the experiences of cities that, through the introduction of regulations and planning indications, have succeeded in limiting effects of overbuilding and the urban heat island, and the urban heat island, identifying shared solutions between public administrations and citizens, who, synergically, contribute to the reintroduction, management and maintenance of new green areas within the city. The research methodology can be framed within the domains of literature review and the strategy of case-study and correlational research [4]. The paper proposes a reading of some ecological indicators used at the international and national level for measuring/quantifying the value of ecological performance and/or compensation of green in urban/anthropized environments. The fundamental objective is to analyze these indicators to verify their limits and potential to assess their technical transferability in urban planning regulations. Special attention will be paid to Biotope Area Factor also through the application to the historical town center of Aversa to test this indicator in a stratified urban environment characterized by a low incidence of green areas, a recurring characteristic in Mediterranean historical town centers.