Peak sediment transport during flood events is very important to the sustainability of the Three Gorges Reservoir (TGR), and thus, in-depth research on peak sediment transport must be performed for the refined regulation of this reservoir. The variation in peak sediment transport and its corresponding causes following the completion of the cascade reservoirs in the lower Jinsha River in the TGR are still unclear. In this study, based on daily discharge and suspended sediment concentration time series, hysteresis patterns and peak sediment transport times were used to determine the peak sediment transport variations. The temporal peak sediment transport variations and their origins were revealed based on wave theory and a one-dimensional hydraulic model. The results show that peak sediment hysteresis has become more obvious recently, and the greatest influencing factor is the construction of cascade reservoirs. Rising water levels in the TGR contributed to slowing SSC, doubling the proportion of anti-clockwise patterns, and increasing the peak sediment transport time by approximately 31% after 2003. The cascade reservoirs in the lower Jinsha River reduced the peak discharge by approximately 15%, which had a relatively large influence on the SSC peak, increasing the SSC peak transport time by approximately 22% and increasing the proportion of the anti-clockwise pattern at the inflow reach. These results can provide references for reservoir regulation during flood events; more significant sediment hysteresis means the regulation timing should be changed. The lag between the peak sediment and peak discharge is affected by the flow process and water level and can be used to help develop a reservoir regulation model.

洪水事件期间的峰值泥沙输送对于三峡水库（TGR）的可持续性非常重要，因此，必须对峰值泥沙输送进行深入研究，以对该水库进行精细的调节。三峡水库下游金沙江梯级水库建成后，输沙量峰值的变化及其原因尚不清楚。在这项研究中，基于日排放量和悬浮泥沙浓度时间序列，使用滞后模式和峰值泥沙传输时间来确定峰值泥沙传输变化。基于波浪理论和一维水力模型揭示了沉积物的时空峰值运移变化及其成因。结果表明，最近的峰值沉积物滞后现象变得更加明显，影响最大的是梯级水库的建设。TGR中的水位上升导致SSC减慢，逆时针模式的比例增加了一倍，并且在2003年之后使峰值输沙时间增加了约31％。金沙江下游的梯级水库使峰值流量减少了约15％。 ，它对SSC峰的影响相对较大，SSC峰的运输时间增加了约22％，并且在流入段增加了逆时针模式的比例。这些结果可为洪水期间的水库调度提供参考。更大的沉积物滞后现象意味着应更改调节时间。