Standardized precipitation evapotranspiration index (SPEI) revisited: parameter fitting, evapotranspiration models, tools, datasets and drought monitoring
Standardized precipitation evapotranspiration index (SPEI) revisited: parameter fitting, evapotranspiration models, tools, datasets and drought monitoring
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DOI：
10.1002/joc.3887
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发表时间：
2014-08-01
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影响因子：
--
通讯作者：
Latorre, Borja
中科院分区：
文献类型：
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作者：
Begueria, Santiago;Vicente-Serrano, Sergio M.;Latorre, Borja
标准化降水蒸散指数(SPEI)是在2010年制定的，并已被越来越多的气候学和水文学研究使用。本文的目标是描述为SPI提供灵活和健壮使用的计算选项。特别是，我们给出了估计对数逻辑分布参数以获得标准化值的方法，计算参考蒸散量(ET0)的方法，以及用于计算不同时间尺度下SPI的加权核。我们讨论了ET0和实际蒸散(ETA)方法的使用，以及通过使用观测和全球网格数据得到的SPI序列的不同选择。结果表明，用来计算ET0的方程可以对世界某些地区的SPI产生显著影响。虽然SPI的原始公式是基于标绘位置概率加权矩(PWM)的，但我们现在建议使用无偏PWM进行模型拟合。最后，我们介绍了用于计算和分析SPI系列的新的软件工具、一个更新的全球网格数据库和一个实时干旱监测系统。
The standardized precipitation evapotranspiration index (SPEI) was developed in 2010 and has been used in an increasing number of climatology and hydrology studies. The objective of this article is to describe computing options that provide flexible and robust use of the SPEI. In particular, we present methods for estimating the parameters of the log-logistic distribution for obtaining standardized values, methods for computing reference evapotranspiration (ET0), and weighting kernels used for calculation of the SPEI at different time scales. We discuss the use of alternative ET0 and actual evapotranspiration (ETa) methods and different options on the resulting SPEI series by use of observational and global gridded data. The results indicate that the equation used to calculate ET0 can have a significant effect on the SPEI in some regions of the world. Although the original formulation of the SPEI was based on plotting-positions Probability Weighted Moment (PWM), we now recommend use of unbiased PWM for model fitting. Finally, we present new software tools for computation and analysis of SPEI series, an updated global gridded database, and a real-time drought-monitoring system.