Urban heat islands: Potential effect of organic and structured urban configurations on temperature variations in Dubai, UAE

Urban heat islands are phenomena that occur coupled with rapid urban developments. The study was carried out to show the effect of organic and structured urban configurations on temperature variations throughout the year, especially in summer. The study investigated a larger area of the city rather than merely building-to-building relationships. It went beyond the confinement of street and building geometries and investigated how a number of these geometries put together in one context contributed to temperature variations. Computer simulation software was used to simulate three different urban configurations, representing an organic configuration in the Bastakiyah model and two structured configurations represented in the Orthogonal and Volume Ortho configurations. The simulations were carried out in Dubai, UAE for summer, winter, and autumn with fixed initial input temperature value of 32 °C and varying initial wind speeds (0.1 m/s and 3.6 m/s; and 7 m/s for summer case only).Assessment of the results showed that the organic configuration recorded lower temperatures in summer than both the structured configurations. The Orthogonal structured configuration did not behave as an intermediate configuration between the organic and highly structured grid configurations. The Volume Ortho configuration, though recorded the highest wind speeds, did not result in lower temperature values. It was shown that different configurations manipulated the behavior of the wind within the configuration. The sky-view factor and standard deviation were plausible explanations in the absence of obvious trends in some cases, and showed how urban configurations impacted temperature variations. It was concluded that, given this specific site location and the alignment of prevailing winds parallel to the roads, the organic configuration showed the better thermal performance amongst the three configurations.

► Computer simulation used to study impact of urban configurations on temperature variation.
► Urban configuration is the primary factor impacting temperature variations, not wind.
► Configuration shape was the factor in manipulating the wind within it.
► Orienting roads & streets towards the wind contributed in flushing out temperature.
► Centralized configuration (Bastakiyah) was cooler in summer & autumn than the others.