The impact of urban form on urban heat island variation in a Mediterranean cities

The Urban Heat Island (UHI) effect has increased with the increase in urbanisation and climate change, especially in cities with arid climates. This study aims to understand the influence of urban forms on creating UHIs by assessing seven sites in a case study in Mostaganem city, which is located on the Mediterranean coast in northern Algeria. A weather station and an infrared thermometer were used to collect the thermal data from the selected sites (S1 to S7). Site S1 was modelled and simulated using ENVI-met software to evaluate the UHI effect on the open area bounded by the surrounding buildings. The simulation data was then validated by the real time data collected from the actual site. Thereafter, seven common urban form configurations were identified and modelled around the same site (S1), and simulated for their individual impacts, one by one. The simulation results were compared in terms of air temperature, wind speed, and ground surface temperature, not to mention that the influence of the different urban forms contributed to the UHI effect in the bounded area. Semi-enclosed configurations of the urban forms that were protected from direct solar radiation recorded the lowest air and ground temperatures, while the difference between temperatures on the site rose to 2 °C in the hottest hours of the day.