Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin, 300387, China.
Environ Sci Pollut Res Int. 2019 Apr;26(11):10695-10707. doi: 10.1007/s11356-019-04529-z. Epub 2019 Feb 18.
The standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI) based on two different methods were calculated using monthly meteorological data from the Yangtze River Basin. According to the completeness and length of dataset, the monthly data of 35 meteorological stations from 1959 to 2017 were applied in this study. The results revealed that the SPEI calculated by the Penman-Monteith (PM) method performed better than the SPI and the SPEI based on the Thornthwaite (TH) method. Since SPEI_PM considered more meteorological factors and detailed physical processes, it obtained the most reasonable and accurate results of drought trends. Using the variations of SPEI_PM to analyze the decadal changes of drought characteristics in the basin, it could be found that 1980-1989 and 1990-1999 were the most humid periods in the basin, while the drought events became more frequent and severe in the recent decade. The spatial distributions of drought trend, duration and frequency indicated that the stations located in the midstream of the river were most prone to drought events, followed by the upper reaches. Our results provided more information for the regions where severe droughts occurred frequently and last longer, and more attention should be paid to these regions in future catchment management.
利用长江流域逐月气象资料，计算了基于两种不同方法的标准化降水指数（SPI）和标准化降水蒸散指数（SPEI）。根据数据集的完整性和长度，本研究应用了 1959 年至 2017 年 35 个气象站的逐月数据。结果表明，彭曼-蒙蒂思（PM）方法计算的 SPEI 优于 SPI 和基于桑斯维特（TH）方法的 SPEI。由于 SPEI_PM 考虑了更多的气象因素和详细的物理过程，因此它获得了最合理和准确的干旱趋势结果。利用 SPEI_PM 的变化分析流域干旱特征的年代际变化，可以发现 1980-1989 年和 1990-1999 年是流域最湿润的时期，而近十年来干旱事件变得更加频繁和严重。干旱趋势、持续时间和频率的空间分布表明，位于河流中游的站点最容易发生干旱事件，其次是上游。我们的结果为经常发生严重干旱且持续时间较长的地区提供了更多信息，在未来的集水区管理中应更加关注这些地区。
