應用Landsat-8影像探討臺中市新社花海節對地區溫度變化之影響

現今氣溫的上升、氣候變遷與全球暖化是全球相當熱門的議題。根據研究指出，人為活動導致土地利用改變，是造成地表溫度變化與熱島效應的主因之一。近年來臺灣舉辦許多季節性質活動，造成活動地區土地利用的變化，同時亦會湧入大量的人潮與車流量，使地表溫度也隨之產生變化。多數人對於熱島效應只會聯想到都市，然而非都市地區的人為活動亦可能造成地表溫度的變化，進而導致地區微氣候的改變，因此本研究針對季節性活動與地表溫度及熱島效應的關係做完整探討與呈現。本研究採用Landsat-8熱紅外影像，結合遙感探測技術進行地表溫度反演，探討臺中市新社花海節舉辦，對於地區地表溫度及熱島強度的影響，藉由監督式分類法進行地物分類，並給予各自的輻射值，藉由地表溫度反演算式得到研究區域之成果，除了區域性比較，也採用花海季節與非季節的資料，藉此增加時間性比較。研究結果顯示，在花海季節時期新社地區之地表平均溫度有升高的現象，並且逼近臺中市其他高溫地區，如：大里工業區、臺中火力發電廠，顯示非都市地區的短暫性人為活動及地表覆蓋之變化，可能對地表溫度造成影響。

關鍵字

地表溫度； Landsat-8 ；季節活動；土地使用；熱島效應

並列摘要

Nowadays the rising of temperature making global warming and climate change becomes very popular topics. Previous studies pointed out that human activity is one of the causes of the heat island effect. In Taiwan, more and more seasonal tourism activities are held in recent years along with the improvement of life quality. However, such activities attract a lot of crowds and traffic flow, and change the heat island intensity. In order to monitor this effect, this study uses thermal infrared channels of Landsat series imagery and retrieves the ground temperature based on the methodology proposed by Jiménez-Muñoz et al. (2014) and Rozenstein et al. (2014). Xinshe flowery field in Taichung City is chosen to monitor the change of heat island effect during different periods. With supervised maximum likelihood classification, land features are divided into four categories: water, soil, impervious surface and vegetation; and then the emissivity values are assigned to each category. The results show that the land surface temperature of the flowery field has indeed risen during the seasonal activities. Besides, the land surface temperature in the flowery field is as high as other heat areas in Taichung, such as Tali Industrial District and Taichung Thermal Power Plant. This confirms that impacts of changes in land use/cover and human activities may influence the land surface temperature.