以熱舒適觀點探討台灣氣候變遷之研究

Abstract

本研究探討臺灣在氣候變遷與都市化影響下，戶外熱舒適度的長期變遷趨勢，並針對北、中、南、東共16個具代表性的城市與鄉鎮進行分析，涵蓋都市、沿海、山區與旅遊景點等多元類型，呈現熱環境變遷的空間差異。研究以UTCI（通用熱舒適指標）為主，輔以ISO 7730之加權指數法，計算過熱嚴重度與時數，資料涵蓋1990年至2024年逐時氣象紀錄，進行時間序列與UTCI分類分布分析。 結果指出，大多數城市出現明顯升溫與熱暴露加劇，臺中、高雄、臺北與新竹等高密度都市過熱嚴重度多達過去的兩倍，顯示都市化與熱島效應的強化。相比之下，高海拔地區如阿里山與日月潭仍維持涼爽，沿海城市如淡水與梧棲則因海陸風具部分緩衝效果，唯熱舒適亦隨開發加速惡化。 UTCI分類結果顯示，舒適區占比逐年下降，過熱區（MH至EH）顯著增加，尤以夏季與白天時段為主，熱暴露日益常態化。儘管部分東部與南部城市仍有冷涼月份，但冬季過冷強度明顯減弱，反映氣候暖化的全面影響。 本研究建議政策應針對不同地區微氣候條件，納入UTCI與ISO指標進行熱風險監測與調適，包括提升都市綠地、改善通風設計、發展高山與沿海庇護區功能，並將熱舒適納入觀光與都市規劃。研究成果有助建立具地域適用性的評估模型，強化城市面對高溫風險之調適能力與政策韌性。

This study investigates the long-term trends of outdoor thermal comfort in Taiwan under the dual influences of climate change and urbanization. A total of 16 representative cities and towns across northern, central, southern, and eastern Taiwan were analyzed, covering a variety of urban forms, including metropolitan areas, coastal towns, mountainous regions, and popular tourist destinations. The Universal Thermal Climate Index (UTCI) served as the primary assessment tool, supplemented by the ISO 7730 weighting factor method to calculate indicators such as heat stress severity and total hours of heat exposure. The analysis utilized hourly meteorological data from 1990 to 2024, focusing on temporal trends and UTCI-based thermal comfort classification. The results reveal a significant increase in temperature and heat exposure in most cities, particularly in densely populated areas such as Taichung, Kaohsiung, Taipei, and Hsinchu, where heat stress severity has more than doubled compared to earlier periods—highlighting the intensified impact of urban heat islands. In contrast, high-altitude regions such as Alishan and Sun Moon Lake maintained relatively cool conditions. Coastal areas like Tamsui and Wuqi, influenced by sea-land breeze effects, showed partial buffering, though thermal comfort conditions also deteriorated with ongoing urban development. UTCI classification results indicate a continual decline in the proportion of comfortable conditions (NO and SLC), while the share of heat stress categories (from Moderate Heat to Extreme Heat) increased markedly, especially during summer and daytime hours—signifying a normalization of extreme heat exposure. Although some eastern and southern cities still experience cooler months, the severity and duration of cold stress have significantly declined, reflecting a broader trend of winter warming under climate change. This study recommends that policies account for regional microclimatic differences and integrate UTCI and ISO-based indicators into heat risk monitoring and adaptation strategies. Key suggestions include expanding urban green coverage, enhancing night-time ventilation, designating highland and coastal areas as climate refuges, and incorporating thermal comfort considerations into tourism and urban planning. The findings provide a regionally adaptable evaluation framework, offering valuable insights for enhancing urban resilience to future heat risks.