應用遙測技術與大氣環流模式探討氣候變遷對台東集水區蒸發散之影響

ESTIMATION OF EVAPOTRANSPIRATION CHANGE OF TAITUNG WATERSHED UNDER CLIMATE CHANGES USING REMOTE SENSING AND GCM MODELS

鍾綉雯(Hsiu-Wen Chung) ； 吳治達(Chih-Da Wu) ； 林士淵(Shih-Yuan Lin) ； 林俊德(Chun-Te Lin) ； 莊永忠(Yung-Chung Chuang)

《中華林學季刊》 49卷2期 (2016/06) Pp. 101-116

摘要

氣候變遷已嚴重衝擊地球上水文循環系統之動態平衡，蒸發散為地表水回歸大氣之最主要機制，故如何評估氣候變遷對於蒸發散之影響，對水資源管理實至為重要。近年來隨著遙感探測技術的進步，結合衛星影像與地表能量平衡公式以可有效推估大尺度蒸發散量之變化。基於此，本研究採用美國太空總署(National aeronautics and spaceadministration, NASA)透過MODIS衛星影像所推估之全球地表蒸發散資料為材料，分析台東集水區蒸發散之時空變異；進一步建立蒸發散與溫度、降雨等氣象變數之迴歸模式後；並結合TaiWAP氣候變遷模擬程式、大氣環流模式(General circulation model, GCM)、以及IPCC第五次評估報告所設定之代表濃度途徑(Representative concentration pathways, RCPs)之情境資料，以推估在氣候變遷影響下，台東集水區未來蒸發散的可能變化趨勢。研究結果指出，台東集水區在2003~2013年間蒸發散於夏季最旺盛，冬季較低，而研究區內之蒸發散亦具有空間分布之特性；此外，氣溫與蒸發散具有顯著正相關(p ＜ 0.01)，模式之R^2為0.75。至於未來氣候變遷之模擬結果顯示，四種未來暖化情境推估所得之蒸發散均較現況為高，其中又以RCP8.5之蒸發散量最大，由此可知，溫室效應與全球暖化確實會影響區域蒸發散量，進而衝擊水文循環，相關成果可供相關部門進行綠資源與水資源管理之參考。

關鍵字

蒸發散 ； 氣候變遷 ； MODIS ； 遙感探測 ； 大氣環流模式

並列摘要

Evapotranspiration (ET) is one of the processes in hydrological cycle expected to be highly sensitive to climate change. In order to achieve a comprehensive water resources management regime, it is critical to understand the potential impacts of climate change on ET. This study used a MODIS ET product produced by National Aeronautics and Space Administration (NASA), U.S.A. to assess the spatiotemporal variability of ET within Taitung watershed. A stepwise linear regression was then applied to develop the predicted model of ET based on weather parameters, such as air temperature and precipitation. Finally, future weather data generated by the TaiWAP program coupled with a General Circulation Model (GCM) and Representative Concentration Pathways (RCPs) established by IPCC fifth assessment report (AR5) were input into the developed model to estimate future ET under climate change scenarios. Firstly, from the archive data (2003-2013) collected over Taitung watershed, we found that ET reached a peak in summer season, where the spatial pattern of ET was also observed. With the collected ET data, the model was developed successfully with a R^2 value of 0.75, where air temperature showed a significant positive association (p ＜ 0.01) with ET. Based on the model, ET values obtained from all tested climate change scenarios were derived; revealing that ET in the near future will be higher than the present observations.

並列關鍵字

Evapotranspiration (ET) ； Climate Change ； MODIS ； Remote Sensing ； General Circulation Model