Impact of development on Baghdad’s urban microclimate and human thermal comfort

Abstract

Achieving sustainability by improving the urban microclimate is a key principle in mitigating the urban heat island (UHI) effect. This study focuses on the reduction of the urban heat island phenomena in a combination of historical compacted areas with multi-storey housing projects in Baghdad’s Al-Karkh district to identify better urban solutions by examining human thermal satisfaction levels via certain urban alterations. Changes were simulated using ENVI-Met and RayMan-pro modelling programmes. Findings suggest that the UHI effect can be reduced by urban interventions and greenery and high-albedo construction materials to influence the mean radiant temperature (Tmrt) factor while simultaneously respecting the height to width ratio of buildings. The urban geometry of a compacted traditional area is one solution to severe summers experienced in Baghdad. Despite the physiological equivalent temperature (PET) level declination reaching 32.2 °C at 3:00 pm, thermal stress levels in compact areas had halved, providing ideal comfort levels that remained constant most of the day. With the growing need for urban development, a concentration of modern high-rise structures can offer tolerable solutions by providing ample shade by casting shadows, in addition to considering wind speed and direction to enhance the urban microclimate and enabling human thermal comfort in arid areas.