Seasonal Effects of Urban form (H/W Ratio) on Outdoor Thermal Environment (MRT and AT) in a Hot-Arid Climate: The Case of Biskra, Algeria
DOI:
https://doi.org/10.22399/ijcesen.5242Keywords:
Urban morphology , Mean Radiant Temperature , Air Temperature , regression analyses , ENVI-met softwareAbstract
Urban morphology plays a major role in shaping outdoor thermal environments in hot-arid cities through its influence on solar exposure, airflow, and heat storage processes. This study investigates the seasonal relationship between urban form , expressed by the height-to-width ratio (H/W), and outdoor thermal conditions represented by Mean Radiant Temperature (MRT) and Air Temperature (AT) in Biskra, Algeria. Numerical simulations were performed using ENVI-met for three residential neighborhoods characterized by different urban configurations. Correlation and regression analyses were applied to quantify the relationship between H/W ratio and thermal variables during summer and winter periods.The results showed significant thermal differences between the investigated neighborhoods. In winter, neighborhood N1 recorded the highest MRT and AT values, estimated at 55.48°C and 22.22°C, respectively, while N3 exhibited the lowest values. Similarly, during summer, N1 showed the highest MRT and AT values, reaching 67.59°C and 41.04°C, whereas N3 recorded the lowest thermal conditions.Statistical analysis revealed a strong negative correlation between H/W ratio and MRT during summer R=−0.895,R2=0.801, while AT also exhibited a very strong inverse relationship with H/W R=−0.985,R2=0.971. In winter, MRT responses became weaker, whereas AT showed a positive relationship with H/W, indicating enhanced heat retention within compact urban canyons. The findings demonstrate that compact urban forms can effectively reduce summer thermal stress while improving winter thermal retention, highlighting the importance of climate-responsive urban design strategies in hot-arid environments.
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