## 1 Introduction  
The rapid urbanization and population growth have led to an escalation in human activities within cities, intensifying their impact on the global climate [1]. This phenomenon has resulted in a gradual increase in average surface temperatures, rising sea levels, and the proliferation of extreme weather events. Consequently, these issues have garnered significant attention and concern worldwide. According to the annual global climate report released by the World Meteorological Organization, the period spanning from 2015 to 2021 ranked as the seven warmest years on record since data collection began in 1850 [2]. Furthermore, predictions indicate that global temperatures will continue to rise over the five-year period from 2022 to 2026. The annual average global surface temperature is projected to surpass pre-industrial levels, with an increase ranging from 1.1 to 1.7 \({}^{\circ}\)C. Being an island nation, Taiwan is susceptible to the influence of warm, humid air masses and ocean currents, resulting in a hot and rainy climate. Particularly during the summer months, temperatures consistently break new records each year. According to the Global and Taiwan Temperature Trend Analysis Report released by the Central Weather Bureau, data from the past three decades (1991-2020) indicate a temperature trend of a 0.30 \({}^{\circ}\)C increase every decade across 13 flat weather stations, surpassing the global average of 0.21 \({}^{\circ}\)C per decade. Hence, addressing the ongoing rise in temperatures necessitates attention, alongside the implementation of corresponding measures to mitigate the challenges posed by urban heat islands and alleviate the myriad adverse effects associated with poor thermal comfort on our daily lives [3; 4]. Over the past decade, the issue of the heat island effect has garnered considerable public attention. The proliferation of cement buildings, the diminishing presence of open spaces and green areas, and the prevalence of poorly ventilated designs have become increasingly commonplace. These trends have exacerbated the severity of the urban heat island effect, thereby adversely impacting the microclimate of urban areas [5]. Tunghai University's campus has traditionally served as a mitigating factor for the urban thermal environment within the city. However, with evolving societal needs and increased usage demands, factors such as burgeoning campus infrastructure, diminishing forested areas, expanding impermeable surfaces, and heightened energy consumption have contributed to an artificial increase in heat within the campus environment, consequently affecting its microclimate. The adverse thermal conditions have profound implications for the physical and mental well-being of students. Additionally, the university's second campus, once a pasture with sparse tree coverage and primarily grassland, lacks adequate shading. Past studies have highlighted that urban vegetation primarily provides cooling through shading, followed by evapotranspiration [6]. The scarcity of trees leaves the second campus less shaded, thus resulting in inferior thermal comfort compared to the first campus. Moreover, with plans for the establishment of a Taichung MRT station in close proximity to Tunghai University, considerations for the campus's future development have prompted the redesign of roads on the second campus. The objective is to foster a pedestrian-friendly environment. Notably, the sidewalk along the south side of the Department of Music and Arts Building, situated adjacent to the newly planned east-west main thoroughflare named Tunghai Avenue, currently lacks adequate tree coverage. This renders pedestrians vulnerable to prolonged sun exposure throughout the day, leading to thermal discomfort [7; 8]. The objectives of this study are to investigate the impact of various planting configurations on the urban thermal environment and their role in enhancing thermal comfort.