Liu Jian, Xia Jun, Wang Mingsen
Post-Doctoral Research Center, Water Research Institute of Shandong Province, Shandong Provincial Academician Workstation, Jinan, 250014, China.
State Key Laboratory of Water Resources Engineering and Management, School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan, 430072, China.
Sci Rep. 2025 Apr 2;15(1):11268. doi: 10.1038/s41598-024-83522-0.
With global environmental change, an in-depth understanding of the changing patterns in the frequency, duration and severity of drought events is of great significance to regional water resources management and agricultural production. The standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI) are two frequently used meteorological drought indices in characterizing the drought characteristics. The elucidation of the differences between the two indices is an important work to reduce the uncertainty in drought hazard analysis and give suggestions of the appropriate index for the regional drought detection. Shandong Province is considered to be one of the major agricultural production bases in northern China. However, the comparative analysis of the suitability of SPI and SPEI for this area and the spatial variability of drought hazard have not been systematically studied, which forms the basis for this research. In this study, we identified drought events according to run theory with consideration of merging neighboring medium-term drought events. The results showed that both SPI and SPEI can efficiently describe drought in the study area and drought events identified by these two indices were quite similar. The drought duration and severity of the most severe drought event identified by SPI were 11 months and 12.8, respectively, with a joint return period of 90 years, and the drought duration and severity of the most severe drought event identified by SPEI were 12 months and 12.98, with a joint return period of 65 years. The duration and severity of drought given by SPEI, however, were generally longer and larger than those given by SPI at the same meteorological station. A comparison of the return period using the bivariate copula function indicated that minor differences existed for the same drought event in the same meteorological station of SPI and SPEI. The spatial distributions of mean drought duration and severity as well as the return periods suggested that the northwest part of the study area and Weifang city were more likely to experience longer and more severe drought events, which also indicated a relatively higher potential for drought hazard in these areas.
随着全球环境变化，深入了解干旱事件的频率、持续时间和严重程度的变化模式，对于区域水资源管理和农业生产具有重要意义。标准化降水指数（SPI）和标准化降水蒸散指数（SPEI）是表征干旱特征时常用的两个气象干旱指数。阐明这两个指数之间的差异，是减少干旱灾害分析不确定性并为区域干旱监测推荐合适指数的一项重要工作。山东省被认为是中国北方主要的农业生产基地之一。然而，SPI和SPEI对该地区的适用性比较分析以及干旱灾害的空间变异性尚未得到系统研究，这构成了本研究的基础。在本研究中，我们根据游程理论识别干旱事件，并考虑合并相邻的中期干旱事件。结果表明，SPI和SPEI都能有效描述研究区域的干旱情况，且这两个指数识别出的干旱事件非常相似。SPI识别出的最严重干旱事件的干旱持续时间和严重程度分别为11个月和12.8，联合重现期为90年；SPEI识别出的最严重干旱事件的干旱持续时间和严重程度分别为12个月和12.98，联合重现期为65年。然而，在同一气象站，SPEI给出的干旱持续时间和严重程度通常比SPI给出的更长、更大。使用二元Copula函数对重现期进行比较表明，在同一气象站，同一干旱事件的SPI和SPEI之间存在微小差异。平均干旱持续时间、严重程度以及重现期的空间分布表明，研究区域的西北部和潍坊市更有可能经历更长、更严重的干旱事件，这也表明这些地区的干旱灾害潜在可能性相对较高。
