Simulation-based educational approach toward improving thermal outdoor comfort for pedestrians in semi-arid climate

Abstract

The urban cooling is the most effective strategy to fight the urban climate change effects in summertime. Thus, searching urban cool islands can remedy the rise of urban temperatures. This study aims to consider cool urban pathways offering optimal levels of thermal comfort in downtown Guelma during summer overheating. This involves researching the appropriate tree ratio and typology, tree layout and suitable configurations of water bodies of outdoor spaces. The scientific methodology is made through either straightforward step included on-site measurements and calculating the difference of urban temperatures to select five outdoor spaces with maximum heat stress. As our study also aims to improve the outdoor thermal comfort by natural elements, it simulates different scenarios of the selected stations using ENVI-Met model and exploiting the real field measurement of the urban microclimate. The most significant reductions in thermal comfort levels (UTCI) over three thermal phases identify the coolest urban pathways. Consequently, we confirmed that considering cool pathways spanning from station S2 to station S8 is possible with optimal thermal comfort levels over the day; 0.46-6.9°C in the morning phase, 0.94-3.87°C in the hot thermal phase and 1.42-3.54°C in the thermal relief phase. The findings indicate three main effects of microclimatic regulation underlie the improvement of the thermal comfort levels: tree cooling effect with (Ta ≤ 1.1°C), cooling effect of water bodies (Ta ≤ 0.3°C) and cooling effect of trees in combination with water bodies (Ta ≤ 1.9°C).