The role of vegetation in outdoor thermal comfort of traditional alleyways in hot arid climates

This study investigates the effect of aspect ratio and vegetation on microclimatic conditions of an alleyway. Microclimatic conditions are increasingly being affected by the growing urban densities. The hotter conditions in the GCC countries, such as Oman, are leading to excessive use of transportation and reduced physical activity of the residents. Enhancing the thermal conditions can encourage residents to spend more time outdoors. Vegetations are a feature that can improve the thermal environment for pedestrians by providing shading and cooling effects from evaporation. This study investigates the effect of aspect ratio and vegetation on the thermal conditions of an alleyway by modelling and simulating alleyways with different types of vegetation using computational fluid dynamics (CFD) and comparing the results with a base case. The findings indicate that vegetation results in significant temperature reductions, up to 7°C, depending on the physical and geometrical properties of the plant, the size of the alleyway, and the wind speed.