Abstract Although numerous studies have investigated the relationships between hydrological drought (HD) and meteorological drought (MD) in different regions, few studies have examined the influence of reservoir operations during drought periods on such relationships, particularly at multiple time scales. This study presents a useful framework to examine the influences of reservoir operation rules during drought periods on the multi-scale correlations between HD and MD. Two standardized drought indices (Standardized Streamflow Index (SSI) and Standardized Precipitation Index (SPI)) with different timescales (1, 3, 6, 12, and 24 months) were used to compare the pre-reservoir and post-reservoir periods. Also, a simple algorithm was proposed to examine the difference value (Dvalue) between the inflow and outflow under different reservoir operation rules and it was used to evaluate the impacts of the reservoir operation rules during the drought on the correlation of the HD and MD. Monthly streamflow and precipitation records from 1960 to 2015 and monthly inflow and outflow records of a large reservoir (Xinfengjiang reservoir) during 1974–2009 in the basin of the Dongjiang River in south China were used to demonstrate the applicability of the analysis methodology. The results indicate that (1) the reservoir operations during the post-reservoir period (1974–2015) exerted a significant influence (positive impact) on the evolution of the short-term (1 and 3 months) HD by reducing the drought duration and alleviating its magnitude and altered the linear correlation between the HD and MD compared to the pre-reservoir period (1960–1972). However, the effects on the long-term (e.g., 12 and 24 months) HD and its correlation with the MD were not apparent. (2) The impacts of the reservoir operation under the drought condition on the relationship between the HD and MD were clearly different from those under normal rules. This study provides additional information for policy-makers to regarding reservoir management during a drought.

中文翻译：

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水库运行对水文干旱与气象干旱多尺度相关性的影响

摘要 尽管大量研究调查了不同地区水文干旱（HD）与气象干旱（MD）之间的关系，但很少有研究探讨干旱期间水库运行对这种关系的影响，尤其是在多个时间尺度上。本研究提供了一个有用的框架来检查干旱期间水库运行规则对 HD 和 MD 之间多尺度相关性的影响。使用不同时间尺度（1、3、6、12和24个月）的两个标准化干旱指数（标准化流量指数（SSI）和标准化降水指数（SPI））来比较水库前和水库后时期。还，提出了一种简单的算法来检验不同水库运行规则下的流入和流出之间的差值（D值），并用于评估干旱期间水库运行规则对HD和MD相关性的影响。以华南东江流域1960-2015年的月流量和降水记录以及1974-2009年华南东江流域大型水库（新丰江水库）的月流入和流出记录证明了该分析方法的适用性。结果表明：（1）水库后时期（1974-2015）的水库运行通过减少干旱持续时间和对短期（1和3个月）HD的演变产生了显着影响（积极影响）。与储层前时期（1960-1972）相比，减轻了其幅度并改变了 HD 和 MD 之间的线性相关性。然而，对长期（例如，12 和 24 个月）HD 的影响及其与 MD 的相关性并不明显。(2)干旱条件下水库运行对HD与MD关系的影响与正常情况下明显不同。这项研究为决策者提供了有关干旱期间水库管理的更多信息。对长期（例如，12 和 24 个月）HD 的影响及其与 MD 的相关性不明显。(2)干旱条件下水库运行对HD与MD关系的影响与正常情况下明显不同。这项研究为决策者提供了有关干旱期间水库管理的更多信息。对长期（例如，12 和 24 个月）HD 的影响及其与 MD 的相关性不明显。(2)干旱条件下水库运行对HD与MD关系的影响与正常情况下明显不同。这项研究为决策者提供了有关干旱期间水库管理的更多信息。