No abstract

In the Middle East and North Africa (MENA) region, studies focused on the relationship between urban planning practice and climatology are still lacking, despite the fact that the latter has nearly three decades of literature in the region and the former has much more. However, such an unfounded relationship that would consider urban sustainability measures is a serious challenge, especially considering the effects of climate change. The Greater Cairo Region (GCR) has recently witnessed numerous serious urban vehicular network re-development, leaving the city less green and in need of strategically re-thinking the plan regarding, and the role of, green infrastructure. Therefore, this study focuses on approaches to the optimization of the urban green infrastructure, in order to reduce solar irradiance in the city and, thus, its effects on the urban climatology. This is carried out by studying one of the East Cairo neighborhoods, named El-Nozha district, as a representative case of the most impacted neighborhoods. In an attempt to quantify these effects, using parametric simulation, the Air Temperature (Ta), Mean Radiant Temperature (Tmrt), Relative Humidity (RH), and Physiological Equivalent Temperature (PET) parameters were calculated before and after introducing urban trees, acting as green infrastructure types that mitigate climate change and the Urban Heat Island (UHI) effect. Our results indicate that an optimized percentage, spacing, location, and arrangement of urban tree canopies can reduce the irradiance flux at the ground surface, having positive implications in terms of mitigating the urban heat island effect.

Gentrification nodes act as city centers in new urban communities where people can work, meet, eat, and exchange. The spatial organization of these nodes, considered complex adaptive systems, is a crucial factor in achieving climate comfort. This paper aims to demonstrate how the spatial organization of these nodes affects their microclimate comfort and can accordingly lead to their spatial resilience. Four predominant gentrification nodes, located in New Cairo and Sheikh Zayed, were selected, playing an essential role in the Egyptian real estate market and affecting urban dynamics in both areas. We argue that their spatial organization and how it affects climate comfort play a crucial role in their urban resilience. We believe that the climate comfort they offer will help them keep attracting the same socioeconomic categories of the population despite the changes in the real estate market and the displacement of urban anchors. Moreover, the findings highlighted that climate comfort, as a component of urban resilience, can be used to acknowledge the behavior of these nodes in the urban fabric. These findings were supported by simulations, interviews with the owners, the architect, and the users’ “closed-ended” questionnaire. The results show that the spatial resilience of two of these nodes is effectively related to climate comfort and the spatial organization that corresponds to users’ needs. Moreover, the results underline that in the case of linear nodes, building massing and materials with high albedo should be considered, as in the multiaxial nodes, the aspect of ratio dimensions and orientation of the space should be well studied.

The trend of upgrading urban areas in Egypt is expanding across the region for better urban mobility patterns. Meanwhile, the concerns towards climate change and creating resilient communities are evolving to avoid the dramatic consequences on urban environments. Street trees offer great benefit in climate moderation, particularly in hot arid regions as in Cairo. In this work, different spatial arrangements and locations for evergreen, deciduous trees and palms at NW street canyon are tested using ENVI-met numerical simulation tool. It is aimed to maximize the cooling effect of tree shade on street facades and attain better pedestrian thermal comfort in peak summer times. This ultimately gives better guidance for urban planners and policymakers towards an improved planting design pattern. Comparing simulation results, it is concluded that evergreen trees located at the building edge can provide up to 6°C cooler walls and up to 3.8°C when placed at the building centre. Whilst other tree species have lower cooling effects. Also, these trees have a great role in attaining better thermal comfort levels for pedestrians at the street level. It is recommended to wisely choose suitable tree species and arrangements to maximize the cooling benefits in the urban environment.