随着城市化进程加快，蓄泄关系恶化导致流域极端洪涝灾害频发。为深入研究城市化流域蓄泄关系，选取秦淮河流域为研究对象，构建流域蓄泄关系曲线，并选取曲线斜率作为蓄泄特征指标，定量表征流域的蓄泄关系及其时空演变特征，进一步结合格兰杰因果检验、偏相关分析法分析流域蓄泄关系的影响因素，并揭示极端暴雨情景下蓄泄关系的响应特征。结果表明：2000年起秦淮河流域主导功能由蓄水向泄水转变，随城市化发展泄水主导更明显；流域蓄泄关系非线性特征呈“减弱-增强”趋势，且受城市化进程及极端暴雨驱动；城市化发展使流域蓄泄关系敏感性普遍降低，其中上游溧水河流域蓄泄关系敏感性最高，敏感性指数最高达0.03 mm^-1。研究成果提出了针对蓄泄关系的定量化指标与方法，为城市防洪规划和流域健康发展提供参考。

[Objective] Accelerating urbanization has deteriorated the balance between water storage and discharge，leading to frequent extreme flood disasters in river basins. Currently，there is a lack of quantitative indicators to characterize the storage-discharge relationship in highly urbanized watersheds，and the underlying mechanisms driving its spatiotemporal evolution remain inadequately understood. This study analyzes the evolving characteristics and influencing mechanisms of the storage-discharge relationship in highly urbanized watersheds，aiming to reveal how extreme rainfall-runoff events impact this fundamental hydrological relationship. [Methods] Taking the Qinhuai River Basin as the study area，we constructed storage-discharge relationship curves and selected the curve slope as a characteristic indicator to quantitatively characterize the relationship and its spatiotemporal evolution. Furthermore，Granger causality tests and partial correlation analyses were employed to identify the influencing factors of the storage-discharge relationship and to reveal its response characteristics under extreme storm scenarios. [Results] （1） The dominant function of the Qinhuai River Basin shifted from water storage to drainage. While storage dominated from 1990 to 1999，the basin transitioned towards drainage after 2000，although dynamic storage volumes remained above 100 mm. Post-2010，intensified urbanization made the drainage-dominant pattern more pronounced. （2） The nonlinearity of the storage-discharge curve exhibited a “weakening-then-strengthening” trend，with urbanization and extreme storms significantly amplifying this nonlinearity. Hydrological responses differed between low- and high-flow regimes，with the latter likely influenced by anthropogenic regulations. （3） The influencing factors of the storage-discharge relationship varied dynamically with flow levels. At low flows，the relationship was primarily driven by extreme precipitation and drainage capacity. At medium flows，the midstream and upstream areas showed a pronounced response to extreme storm characteristics. At high flows，despite increased frequency and intensity of extreme storms，the interaction between the storage-discharge relationship and extreme storm indices weakened，necessitating anthropogenic regulation to ensure basin safety. （4） Urbanization significantly impacted the storage-discharge relationship，generally reducing basin sensitivity and weakening regulation capacity. The upstream Lishui River exhibited the highest sensitivity （0.005，0.013，and 0.03 mm^-1 under high，medium，and low flows，respectively） and the largest variation amplitude under extreme storms，marking it as a critical area for focused management. [Conclusion] The quantitative indicators and methodologies proposed in this study for analyzing storage-discharge relationships provide a valuable scientific reference for urban flood control planning and the sustainable development of river basins.