Human interventions and climate change can heavily influence the large-scale morphological development of tidal basins. This has implications on sediment management strategies, as well as ecological and recreational purposes. Examples of heavily impacted tidal basins are those in the Western Dutch Wadden Sea. The closure of a large sub-basin in 1932 triggered a shift in the sediment budgets of the remaining basins, leading to sediment infilling that is still ongoing. This paper presents a quantitative analysis of the post-closure sediment volumes, differentiating between sand and mud. Analysis of historical sediment composition data combined with bathymetry data revealed that the intervention caused a redistribution of sand and mud sedimentation. The responses of both sediment types differ spatially and temporally. The total infilling of the basins over the last century was substantially caused by mud (~32%, which is much larger than the average mud content in the bed). Initially, large mud volumes accreted in abandoned channels. At present, mud sedimentation along the mainland coast is still ongoing with nearly constant sedimentation rates over the past century, while the net import of sand significantly decreased over time and has been fluctuating around 0 over the last two decades. This research shows the importance of distinguishing between the response of sandy and muddy sediments when analysing the morphodynamic impact of an intervention, since they operate on different time and spatial scales. Sea level rise is currently a major threat for the existence of the Wadden Sea; its future fate will depend on whether the tidal flats are able to keep pace. Our results show that the supply of mud is sufficient to keep pace with the current sea level rise rates.

人类干预和气候变化会严重影响潮汐流域的大规模形态发展。这对沉积物管理策略以及生态和娱乐目的都有影响。受严重影响的潮汐盆地的例子是西荷兰瓦登海的潮汐盆地。1932 年一个大型子盆地的关闭引发了其余盆地沉积物收支的转变，导致仍在进行的沉积物充填。本文对闭合后的沉积物体积进行了定量分析，以区分沙子和泥土。对历史沉积物成分数据结合水深测量数据的分析表明，干预导致了沙泥沉积的重新分布。两种沉积物类型的响应在空间和时间上都不同。上个世纪盆地的总充填主要是由泥浆引起的（~32%，远大于床层中的平均泥浆含量）。最初，大量泥浆堆积在废弃的河道中。目前，大陆沿岸的泥浆沉积仍在进行中，沉积速率在过去一个世纪几乎保持不变，而沙子的净进口量则随着时间的推移显着减少，并在过去的 20 年中一直在 0 附近波动。这项研究表明，在分析干预的形态动力学影响时，区分沙质和泥质沉积物的响应很重要，因为它们在不同的时间和空间尺度上运行。海平面上升目前是瓦登海存在的主要威胁；其未来的命运将取决于滩涂能否跟上步伐。