Sediment supply is a primary factor in determining marsh response to sea level rise and is typically approximated through high‐resolution measurements of suspended sediment concentrations (SSCs) from adjacent tidal channels. However, understanding sediment transport across the marsh itself remains limited by discontinuous measurements of SSC over individual tidal cycles. Here, we use an array of optical turbidity sensors to build a long‐term, continuous record of SSC across a marsh platform and adjacent tidal channel. We find that channel and marsh concentrations are correlated (i.e., coupled) within tidal cycles but are largely decoupled over longer time scales. We also find that net sediment fluxes decline to near zero within 10 m of the marsh edge. Together, these results suggest that large sections of the marsh platform receive minimal sediment independent of flooding frequency or channel sediment supply. Marsh‐centric, as opposed to channel‐centric, measures of sediment supply may better characterize marsh platform vulnerability.

中文翻译：

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通过源解耦和通量收敛，可最大程度地减少向潮汐沼泽平台的沉积物输送。

沉积物供应是确定沼泽对海平面上升反应的主要因素，通常通过高分辨率测量来自相邻潮汐通道的悬浮沉积物浓度（SSC）来估算。但是，对于单个潮汐周期中不连续的SSC测量，仍然难以理解跨沼泽地的沉积物传输。在这里，我们使用光学浊度传感器阵列在沼泽平台和邻近的潮汐通道上建立SSC的长期连续记录。我们发现，河道和沼泽的浓度在一个潮汐周期内是相关的（即耦合的），但在较长的时间尺度上却很大程度上是分离的。我们还发现，在沼泽边缘10 m内，净沉积物通量下降到接近零。一起，这些结果表明，与洪水频率或河道沉积物供应量无关，沼泽平台的大面积沉积物最少。与以河道为中心相比，以沼泽为中心的沉积物供应措施可能更好地表征了沼泽平台的脆弱性。