遙測蒸發散：Penman-Monteith法與地表能量平衡法之探討

Estimate Evapotranspiration from Remote Sensing: Penman-Monteith and Energy Balance Methods

郭振民(Chen-Min Kuo) ； 盧書炫(Shu-Hsuan Lu) ； 游保杉(Pao-Shan Yu)

《航測及遙測學刊》 11卷3期 (2006/09) Pp. 269-281

https://doi.org/10.6574/JPRS.2006.11(3).4

摘要

本研究目的為發展直接應用遙測影像計算蒸發散之方法，利用MODIS衛星影像建立Penman-Monteith公式與地表能量平衡模式－Surface Energy Balance Algorithm for Land(SEBAL)及Simplified Surface Energy Balance Index(S-SEBI)模式－所需要的氣象因子之回歸式，並將估算結果轉換為全日實際蒸發散量與測站蒸發皿觀測值比較，根據評鑑指標優選適合台灣西半部地區遙測資料估算蒸發散量之方法，並討論不同估算方法中各氣象因子對蒸發散估算結果之影響。研究結果顯示以Penman-Monteith公式估算結果最佳(ME=1.07mm/day, RMSE=1.28mm/day)，而誤差來自於淨輻射量的影響；SEBAL模式結果較差(ME=1.61mm/day, RMSE=1.91mm/day)，誤差來源為淨輻射量；S-SEBI模式結果最差(ME=2.07mm/day, RMSE=2.68mm/day)，乃由於影像解析度不足造成混合像元現象，而影響蒸發散比值之估算。

關鍵字

蒸發散量 ； 衛星遙測 ； MODIS ； Penman-Monteith ； SEBAL ； S-SEBI

並列摘要

The study is aimed to derive the regional evapotranspiration scheme by using MODIS images based on both Penman-Monteith and surface energy balance methods (SEBAL and S-SEBI). The observations of meteorological stations in Western Taiwan are used to verify with the estimations to suggest the proper method. Then, the influences of evapotranspiration from the meteorological factors are discussed. We have concluded the Penman-Monteith method has the best performance (ME=1.07mm/day, RMSE=1.28mm/day), and is affected by the net radiation. The SEBAL model (ME=1.61mm/day, RMSE=1.91mm/day) is slightly less performance than Penman-Monteith method and is affected by the net radiation. The accuracy of S-SEBI mode is the worst (ME=2.07mm/day, RMSE=2.68mm/day). It is due to the mixed-pixel of the low resolution in MODIS images and leads to the inaccuracy of evaporative fraction. Therefore, we can suggest that Penman-Monteith method is the best method to estimate evapotranspiration with MODIS images. However, we should improve the estimation of the net radiation and adopt high resolution images in the future.

並列關鍵字

Evapotranspiration ； Remote Sensing ； MODIS ； Penman-Monteith ； SEBAL ； S-SEBI