應用MODIS衛星影像推估台灣地區之蒸發散量

Using MODIS Satellite Images to Estimate Evapotranspiration in Taiwan

陳朝圳(Chaur-Tzuhn Chen) ； 吳守從(Shou-Tsung Wu) ； 江彥鋒(Yan-Fang Chiang)

《台灣林業科學》 21卷2期 (2006/06) Pp. 249-261

https://doi.org/10.7075/TJFS.200606.0249

摘要

蒸發散量是影響水文循環的重要因子，然以往在估算蒸發散量的研究中，大都對於研究區域土地利用型之非均質性缺乏考慮，更無法合理表示蒸發散量之空間變化情形，因而難以達成有效監控與管理水資源之境界。本研究採用SEBAL模式，配合四期不同季節之MODIS影像估算全台灣之蒸發散量，並探討不同土地利用類型蒸發散量的差異性。研究結果顯示，利用MODIS影像推估地面蒸發散量是一種可接受之方式；而四種土地利用類型中，以森林地的蒸發散量最高，水體次之，都市用地再次之，而農業用地為最末，且彼此間具有極顯著差異。利用SEBAL模式推估蒸發散量，以晴朗無雲之地區所得估算結果較佳，因此未來進行蒸發散量估算時，若能選擇多幅晴朗無雲之影像來進行，相信對於準確度的提升會有很好的幫助。

關鍵字

蒸發散量 ； SEBAL模式 ； MODIS衛星影像

並列摘要

Evapotranspiration (ET) from land is a major component in the hydrological cycle, and much of the research related to estimating ET has only rarely considered different land use types of the study area and is thus still unable to reasonably explain the spacial distribution of ET. Therefore, monitoring and managing water resources in an efficient way are still difficult nowadays. This research adopted the SEBAL model and 4 seasons of MODIS satellite images to estimate the ET for the entire island of Taiwan. We discuss the variability among different land use types. The results of this research showed that using MODIS satellite images to estimate ET is an acceptable method, and the estimated value for forestland was the highest, while that for agricultural land was the lowest. In addition, the estimated ET of different land use types significantly differed when tested with one-way ANOVA. By using the SEBAL model to estimate ET, clear weather was better than cloudy or rainy days. As result, in order to reduce errors of estimation in the future, it is suggested that selecting good images which were shot on clear days is the best policy.

並列關鍵字

evapotranspiration ； SEBAL ； MODIS