Quantifying thermal comfort improvement by palm tree-based street greening, in hot and dry climate

This paper aims to quantify the improvement in outdoor thermal comfort through palm tree-based street greening in hot, dry regions affected by rapid urbanization and climate change. The study was conducted in Sidi Okba, one of the largest oases in Biskra, Algeria, during summer, characterized by its diverse urban housing fabric. Two streets were compared: Str1, located in a traditional vegetation-free urban fabric but surrounded by Phoenix dactylifera palm groves to the northwest and south, and Str2, situated in a contemporary urban fabric with minimal vegetation. The methodology combined field measurements and digital simulations using Envi-Met software to evaluate a greening scenario for Str2 involving palm tree integration. Results revealed that Str1 exhibited superior cooling effects due to its proximity to palm groves, while the proposed greening scenario for Str2 demonstrated significant thermal comfort improvement compared to its current state. Factors such as palm tree density, distribution, and the location of a street within the urban fabric influence microclimatic conditions. The study underscores the efficacy of local palm trees in providing sustainable cooling and their cultural-environmental suitability for hot, arid regions. It urges urban planners to prioritize native vegetation and integrate it into urban development strategies to enhance climate resilience.