The correlation between urban morphology parameters and incident solar radiation performance to enhance pedestrian comfort, case study jeddah, Saudi Arabia

Abstract

Many urban studies have evaluated the impact of urban morphology on the microclimate of cities, and it has been shown that the influence is substantial. One of the significant impacts on outdoor thermal comfort in hot climate cities depends on solar radiation. The city of Jeddah is expected to start constructing a subway in 2020 that is likely to drastically change the behaviors of its inhabitants. Therefore, this study aims to investigate the relationship between modern and contemporary morphology and the potential of incident solar radiation to enhance pedestrian comfort by avoiding transit under this harsh solar radiation. The authors have evaluated the performance of two urban layouts, with different building densities to investigate the extent to which morphological features of the built environment can affect solar penetration on the streets. Moreover, the study assessed the influence of various built parameters such as street geometry (H/W ratio, streets orientations) and the solar indicator (Sky View Factor). Results show that in the low rise building layouts, the orientation of streets and the H/W ratio are not reliable. Moreover, it is difficult to reduce solar radiation penetration on the streets by modifying the morphology. Therefore, other ways should be tested to shade from solar penetration. Furthermore, the authors have observed that for high rise building layouts, pedestrian comfort could be modified through the adjacent morphology.