Mitigating Urban Microclimate Extremes with Vegetation Strategies for Seasonal Temperature Regulation

Abstract

Urban heat and cold islands significantly impact environmental quality and human comfort in urban areas. This study addresses the critical role of vegetation compatibility in mitigating these extremes, particularly in Iran's diverse four-season climate. Unlike previous research, which primarily focuses on summer conditions and often overlooks seasonal variations, this study uniquely investigates the effects of vegetation on air temperature during both summer and winter seasons, specifically analyzing conditions on July 22 and January 22, 2023. This dual-season analysis is crucial as it provides a comprehensive understanding of how vegetation influences urban microclimates throughout the year. Such insights are often missing in the existing literature. The relevance of Arak, Iran, specifically Hesabi Street, is underscored by its representative urban characteristics and climatic variations. Using the software Environmental Meteorology (ENVI-met) 5.0.3, various vegetation scenarios are simulated to assess their impact on heating and cooling loads. The methodology includes a comparison of current conditions, characterized by sparse dense hedge plants, with two alternative scenarios featuring acacia trees (noted for their small leaves). The assessment criteria include maximum cooling and heating loads, measured in degrees Celsius, allowing for a quantitative evaluation of thermal performance. The results reveal that the optimal scenario can reduce the maximum cooling load by 1.87°C in summer and the maximum heating load by 2.13°C in winter. These findings have practical implications for sustainable urban planning, suggesting that strategic vegetation placement can enhance energy efficiency. Future applications of this research may extend to other climates, promoting broader relevance in urban microclimate management.