A modified MOD16 algorithm to estimate evapotranspiration over alpine meadow on the Tibetan Plateau, China
A modified MOD16 algorithm to estimate evapotranspiration over alpine meadow on the Tibetan Plateau, China
复制标题
修正的 MOD16 算法估算中国青藏高原高寒草甸蒸散量
DOI：
10.1016/j.jhydrol.2018.03.054
复制
发表时间：
2017-12
影响因子：
6.4
通讯作者：
Zhang Shiqiang
中科院分区：
文献类型：
--
作者：
Chang Yaping;Qin Dahe;Ding Yongjian;Zhao Qiudong;Zhang Shiqiang
蒸散量（ET）的长期变化对于青藏高原（TP）等极端气候地区的水资源管理至关重要。本研究提出了一种基于MOD16算法的改进算法，用于估算中国青藏高原高寒草甸的全球尺度蒸散量。整合风速和植被高度来估计空气动力阻力，同时根据 Fisher 等人（2008）提出的技术修改了气孔导度的温度和湿度约束。此外，采用Fisher土壤蒸发法来减少土壤蒸发估算的不确定性。选择高原上五个具有代表性的高寒草甸站点来研究改进算法的性能。对使用涡流协方差 (EC) 观察到的 ET 和使用原始算法和修改后的算法估计的 ET 进行了比较。结果表明，改进后的算法性能优于原MOD16算法，确定系数（R-2）从0.26增加到0.68，均方根误差（RMSE）从1.56减小到0.78 mm d(-1)。改进后的算法在苏里站点的降水后天的表现略好于非降水天，其 R-2 (0.70) 较高，RMSE (0.61 mm d(-1)) 较低。相反，阿鲁、唐古拉和葫芦沟站点的非降水日比降水后日得到了更好的结果，这表明改进的算法可能更适合于非降水日的ET估算，其精度高于降水后日的观测误差。改进算法与两种主流方法的比较表明，改进算法可以在青藏高原高寒草甸站点上产生高精度的蒸散数据。
The long-term change of evapotranspiration (ET) is crucial for managing water resources in areas with extreme climates, such as the Tibetan Plateau (TP). This study proposed a modified algorithm for estimating ET based on the MOD16 algorithm on a global scale over alpine meadow on the TP in China. Wind speed and vegetation height were integrated to estimate aerodynamic resistance, while the temperature and moisture constraints for stomatal conductance were revised based on the technique proposed by Fisher et al, (2008). Moreover, Fisher's method for soil evaporation was adopted to reduce the uncertainty in soil evaporation estimation. Five representative alpine meadow sites on the TP were selected to investigate the performance of the modified algorithm. Comparisons were made between the ET observed using the Eddy Covariance (EC) and estimated using both the original and modified algorithms. The results revealed that the modified algorithm performed better than the original MOD16 algorithm with the coefficient of determination (R-2) increasing from 0.26 to 0.68, and root mean square error (RMSE) decreasing from 1.56 to 0.78 mm d(-1). The modified algorithm performed slightly better with a higher R-2 (0.70) and lower RMSE (0.61 mm d(-1)) for after-precipitation days than for non precipitation days at Suli site. Contrarily, better results were obtained for non-precipitation days than for after precipitation days at Arou, Tanggula, and Hulugou sites, indicating that the modified algorithm may be more suitable for estimating ET for non-precipitation days with higher accuracy than for after-precipitation days, which had large observation errors. The comparisons between the modified algorithm and two mainstream methods suggested that the modified algorithm could produce high accuracy ET over the alpine meadow sites on the TP.
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影响因子：
13.5
作者：
Cleugh, Helen A.;Leuning, Ray;Running, Steven W.
通讯作者：
Running, Steven W.
影响因子：
6.3
作者：
Su, Z
通讯作者：
Su, Z
根据水平衡法对流域尺度蒸散量估算进行全球评估
影响因子：
6.4
作者：
Liu, Wenbin;Wang, Lei;Sang, Yan-Fang
通讯作者：
Sang, Yan-Fang
DOI：
10.4135/9781446247501.n1164
发表时间：
2010
期刊：
--
影响因子：
--
作者：
通讯作者：
--
影响因子：
4.3
作者：
JACQUEMIN, B;NOILHAN, J
通讯作者：
NOILHAN, J