Urban areas are attracting increasing scholarly attention due to the numerous challenges that they are facing. Challenges are related to the growth of urban population and to the exacerbation of climate change-related events, such as Urban Heat Island (UHI), where urban areas have higher temperatures than surrounding suburbs. The built environment, i.e., buildings and spaces in-between them, has a high potential in influencing urban microclimate conditions. Therefore, it is of paramount importance to find effective strategies towards urban microclimate improvement. In particular, in the view of urban temperature increase, solutions to improve comfort conditions could increase livability of the outdoors. In this research, pocket parks (PPs), i.e., small parks between buildings, are investigated as a mitigation strategy to improve local microclimate and pedestrians' comfort. PPs, not yet widely studied in literature, are closer (walking-distance) to citizens' home/office, thus more easily usable than traditional parks; they are simpler and less expensive to build and maintain and they possess peculiar characteristics that allow increasing citizens' comfort and safety. The key characteristics of PPs that influence urban local microclimate are linked to their construction materials and morphology. The objective of the present study is to assess, by means of a multi-disciplinary experimental and numerical analysis, which are the characteristics of PPs morphology and materials that allow obtaining the best performance with respect to citizens' comfort and wellbeing. Case study PPs will be selected in dense cities with different climates. Results could be employed towards the improvement of urban local microclimate conditions by urban planners and building designers and will also be relevant for researchers in the field of urban-architecture design and environmental building physicists, to advance the research on UHI counteraction and urban microclimate improvement.
Open public spaces such as urban parks, public squares and sidewalks were investigated in literature as fundamental components of urban areas, where pedestrians spend a huge amount of time. As recalled in previous sections, the construction materials and morphology composing such urban spaces were the subject of numerous studies, under different perspectives. Among these perspectives there were the design and aesthetical ones, as well as that one related to urban microclimate. In the vast majority of the cases, however, these two perspectives remained disconnected, while their integration would lead to a conscious design towards more comfortable and safer open public spaces.
Recently, following the increasing complexity of urban needs and the challenges linked to climate change, research were conducted integrating the influence of construction materials on urban microclimate, or the influence of urban morphology on urban microclimate. Only few articles focused on the integrated analyses of urban parks and urban canyons considering construction elements, morphology, and their coupled effect on urban local microclimate, towards comfort improvement.
The proposed research would apply this innovative integrated and multi-disciplinary approach, coupling design aspects - related to construction elements and morphology- and urban microclimate analysis to peculiar urban spaces, which were not considered in past research.
Indeed, pocket parks (PPs), which are promising open public spaces due to their potential diffusion in dense urban areas, low-cost and simple implementation, are still not widely investigated in literature. The few studies on small/pocket parks that were conducted, considered almost exclusively aesthetical design and social regeneration aspects, leaving aside the topic of urban microclimate and resilience to climate change. Indeed, the potential of PPs with respect to UHI and heatwaves mitigation is promising, and such open spaces could have a significant impact in providing safer and more comfortable spaces to citizens and tourists roaming urban areas.
Thus, the proposed study would fill this gap by considering PPs with the above mentioned, innovative integrated approach. Results would be original and relevant to researchers in the field of urban planning, urban microclimate studies, urban resilience, urban built environment, as a base for further research, as well as for policymakers and urban municipalities, professionals in the field of architecture and urban engineering, as practical indications to improve urban areas resilience by means of simple and low-cost solutions.
In addition to the subject of the research (the PPs) being original and innovative, also the employed methodology constitutes an innovative contribution to the state of the art in built environment and urban microclimate studies. Indeed, the methodology is based on three coupled assessment methods for PPs microclimate as influenced by construction materials and morphology: (i) in field microclimate measurements by means of a portable microclimate station; (ii) in field survey to pedestrians using the PPs and (iii) numerical computation by means of microclimate modeling of the considered PP, with ENVI-met software. The proposed methodology, in addition to being innovative for the coupling of the assessment methods, allows assessing both objective (in field microclimate measurements and numerical modeling) and subjective (in field surveys) comfort sensations by the pedestrians. This is an important feature, that would allow verifying and further addressing the gap, assessed by only few and recent studies, between subjective and objective evaluation of the built environment.
Finally, the proposed methodology would also be validated, allowing a significant advancement of the state of the art and the possibility to serve as a comparison for researchers for further studies on the topic.
The comparison of PPs located in different climates, investigated with the same methodology, would constitute an innovative contribution to the state of the art: indeed, most of the existing studies focus on one specific climate at a time. This specificity, i.e., the need to consider tailored solutions for each specific climate, which is necessary for having significant results, limits the existing studies. Indeed, since there is no standardization for outdoor comfort studies, higher errors are common in studies replicating the same analysis on a the different climate. The proposed research would take a step further, by considering different climates and employing the exact same method on each of them.
In conclusion, the proposed study would provide original and innovative results, by studying a still-non-investigated open space; with an innovative, integrated and multidisciplinary perspective and methodology; for different climates; and could be the base for further studies and applications in dense urban areas, for researchers and policymakers.