隨著經濟發展，工商業發達，人口大量湧入都會地區，致使都市地區相關的硬體建設迅速發展。都會區蓬勃發展的同時，將使地表結構從原本的自然植被，逐漸被人工鋪面取代，造成都市地區氣溫失去平衡，溫度不斷升高，導致都市溫度高於郊區的現象，形成所謂的都市熱島效應，影響都市環境品質。隨著空間資訊與技術的進步，衛星遙測具有高光譜、多尺度、多時序與資料獲取快速等優點，故本研究應用衛星資料探討大台北地區都市熱島效應時空分布之特性。本文利用1990 年至2009 年Landsat 衛星影像，以大台北地區為研究試區，藉由多光譜資訊所計算亮度溫度與植生指數(Normalized DifferenceVegetation Index; NDVI)，分析大台北地區都市熱島強度(Urban Heat Island;UHI)之時空分布特性；另一方面，亦透過衛星資料在地物分類之結果，將地表覆蓋物分為建地、水體以及植被等三種，分析不同地物種類與熱島效應分布情形；最後則利用地表分類結果估算研究試區中的人工鋪面比例(Impervious Surface Area; ISA)，並透過探討ISA 與熱島效應之關係，分析都市發展與都市熱島之互耦現象研究結果顯示，北台灣地區夏季熱島效應較其他季節明顯，大台北地區熱島強度平均可高達6℃，都會中心的溫度明顯高於鄉村地區。若比較1990 年與2009 年大台北地區地表覆蓋物，且人工鋪面比例(ISA)與都市熱島效應有明顯的正向關係，人工鋪面的增加(ΔISA)與熱島強度(UHI)之關係呈指數型態增加，而人工鋪面比例越大的地區都市熱島強度的增幅也越大。Along with the urban development, urban heat island(UHI) effect hasbecome more serious over Greater Taipei Region(GTR). The enhancement ofUHI effect is mainly due to the increase in the area of artificial impervioussurfaces, and will make the impact on the changes of climate as well as theregional precipitation. Therefore, it’s important to monitor the phenomenonof UHI for the metropolis. With the development of spatial informationtechnology, the remote sensing has advantages of high spectral rate,multi-scale images, multi-temporal and fast data acquisition. The applicationof remote sensing has been focused on urban heat island study nowadays. Inpresent research, the UHI effect was investigated by means of remote sensingover GTR.The observation from Landsat TM/ETM sensors during 1990 to 2009 wereused to analyze the spatiotemporal characteristics of UHI effect for the specificareas. The retrievals of brightness temperature, Normalized DifferenceVegetable Index(NDVI), land cover type and impervious surface area(ISA) fromTM/ETM data were examined the correlation to the intensity of UHI.The result indicated that the UHI effect is more severer in summer than theother seasons(spring and winter) in north Taiwan. The intensity of UHI can bemore than 6℃ in summer. For the effect of land cover type on UHI intensity,the urban area type can be about 4℃. The results also indicate that the UHIintensity increased along with the urban development during the past 20 years.By comparing the land cover and land use changes between 1990 and 2009,about 11% vegetative area was replaced by the impervious surface over GTR.In addition, the results showed the good exponential relationship betweenΔISA and ΔUHI, implying that the UHI will be magnified in the areas with largeISA value efficiently, such as the center of megalopolis.
