Urban Ventilation in the Compact City: A Critical Review and a Multidisciplinary Methodology for Improving Sustainability and Resilience in Urban Areas

Abstract

In the last decades, a tendency towards urban tissue densification has been observed to counteract the urban sprawl. Densification may be achieved through more compact built areas, preferring the vertical to the horizontal development of buildings but avoiding bulky high-rise building blocks. This strategy significantly affects several aspects of the microclimate and produces direct and indirect effects on human health and well-being. In this regard, air pollution and heat stress constitute two increasing threats to human health and well-being that need to be faced immediately. The involved phenomena are various, intertwined, and may lead to conflicting results. Hence, regenerating existing, well-structured, and stratified urban areas by densification is not an easy challenge. Urban ventilation may favor the mitigation of detrimental effects of air pollution and heat stress on human life. Therefore, a multidisciplinary methodology is presented for embedding urban ventilation performance evaluation into urban management and planning processes. The scope is to propose a framework for urban renewal plans that is citizens-centered and aims at improving their health and well-being in existing urban areas. The methodology builds upon the performance-based approach and is supported by the conceptual framework and the literature reviews provided through the paper.

Outdoor Microclimate in Courtyard Buildings: Impact of Building Perimeter Configuration and Tree Density

“…In particular, dense urban environments have been proven to considerably worsen ventilation flows and thus affect thermal comfort at pedestrian level [43]. Therefore, Palusci and Cecere recommend urban renewal plans considering how airflows and urban morphology interact because their effects on human life can be either positive or negative [44]. However, most studies focus on idealised urban patterns [45], while studies of real neighbourhood or block layouts are still limited.…”

Forecasting the Impact of the Environmental and Energy Factor to Improve Urban Sustainability by Using (SEM)

“…In order to move to sustainable or more sustainable cities that evolve with technological changes, many theories have emerged, the most important of which will be addressed in this paper, namely: the theory of compact cities, the theory of the just city, the theory of biophilic cities, the theory of resilient cities, the theory of multi-technology cities [11], and the theory of the upward spiral [12] to clarify the goals and principles of environmental, economic, and social development and to know the intellectual orientations of each theory. The aforementioned theories contribute to identifying the intellectual orientations involved under their umbrella and will be addressed in the next paragraphs in detail, through which the main factors and indicators of urban sustainability can be reached (Figure 1).…”

Leveraging the Opportunities of Wind for Cities through Urban Planning and Design: A PRISMA Review

“…Relevant morphological parameters and indices that impact the wind environment may be determined from the urban spatial structure analysis. Studies have included a range of quantifiable urban morphological parameters and indices that influences urban aerodynamics, for example, surface roughness [71,94,95], sky view factors [56,96,97], frontal area density and index [14,32,51], plan area density [13,22,75], building coverage ratio [98], building height and height variance [25], and height-to-width ratio [99]. These morphological parameters are analyzed alongside quantifiable ventilation and energy performance indicators such as temperature changes [14,24,100], age of air [99], air exchange velocity [101], pollutant concentration [59,60,102], energy density [73,103], and turbine capacity factor [71].…”

“…Their review highlighted engineering and technical issues associated with urban wind turbine technologies, and the difficulties of assessing urban wind energy potentials. Palusci and Cecere [13] produced a systematic review on the topic of urban ventilation in compact cities, where they stressed the importance of embedding a multidisciplinary methodology into urban management and planning processes.…”