Recent years, the hydrological connectivity has gained popularity in various research fields, however, its definition and threshold effects at a system scale have not received adequate attention. The current research proposes a promising framework to refine the concept of surface hydrological connectivity by combining hydrodynamic modeling experiments, threshold effects and geostatistical connectivity analysis, exemplified by the flood-pulse-influenced Poyang Lake floodplain system (China). To enhance the inherent linkage between hydrological connectivity and eco-environments, total connectivity (TC), general connectivity (GC), and effective connectivity (EC) were proposed to refine the metrics of hydrological connectivity. The results show that substantial differences between the three connectivity metrics are observed for all target directions, demonstrating that the joint role of water depth and flow velocity may produce more dynamic and complex influences on EC than the other two metrics of TC and GC. Topographically, the connectivity objects/areas within the flood pulse system reveal that the floodplain is a more sensitive area than the lake's main flow channels under different connectivity conditions. The modelling experimental studies show that variations in water depth thresholds are more likely to have a strong effect on connectivity for the dry, rising, and falling limbs, rather than the flooding period, while the flow velocity may exert an opposite threshold effect. The lake-floodplain system is characterized by a dynamic threshold behavior, with seasonally varying water depth and velocity thresholds. This study highlights the importance of redefined connectivity concept for facilitating scientific communication by combining hydrodynamic thresholds and offering recommendations for future connectivity assessments using our proposed metrics of TC, GC, and EC.

近年来，水文连通性已在各个研究领域中普及，但是，其定义和阈值效应在系统规模上并未引起足够的重视。当前的研究提出了一个有前途的框架，通过结合水动力模型试验，阈值效应和地统计连通性分析来完善地表水文连通性的概念，以受洪水脉冲影响的Po阳湖洪泛区系统为例。为了增强水文连通性与生态环境之间的固有联系，提出了总连通性（TC），一般连通性（GC）和有效连通性（EC）来完善水文连通性的指标。结果表明，在所有目标方向上都观察到了三种连通性指标之间的实质性差异，表明水深和流速的共同作用可能比TC和GC的其他两个指标对EC产生更大的动态和复杂影响。从地形上看，洪水脉冲系统中的连通性对象/区域表明，在不同连通性条件下，洪泛区比湖泊的主要水流通道更敏感。建模实验研究表明，水深阈值的变化更可能对干旱，上升和下降肢体的连通性产生强烈影响，而不是洪水时期，而流速可能会施加相反的阈值效应。湖洪泛滥系统的特征是动态阈值行为，随季节变化的水深和速度阈值会有所变化。