Fine sediment represents an important part of the solid flux of rivers. Due to the size of these particles, they are often transported as suspended load. They gradually fill the pores of the substrate forming the hyporheic zone or cover the substrate by settling, resulting in the clogging of the riverbed. Clogging of the major part of the riverbed affects the habitat of invertebrates and reduces the reproduction success of spawning fish. This threat has been reported by a substantial amount of research in the past decades. Human infrastructure (such as reservoirs and hydropower plants), combined with artificial riverbanks and an increased flux of fine sediment in some catchments, has deeply changed the dynamic of rivers. A large number of studies have focused on the impact of clogging on aquatic fauna. The process of deposition of fine sediment has also been the subject of many studies aimed at understanding the role of different parameters (for example, the role of vertical distribution of fine sediment on substrate clogging). Here, the physical mechanisms involved in the deposition of fine sediment are reviewed to give a more comprehensive overview of this complex process. A general description of the process is followed by an analysis of the different parameters that are involved. The influence of flow conditions, substrate composition, hyporheic flow and fine sediment characteristics are analysed in detail. The different models that have been proposed to estimate the depth, quantity and time evolution of the process are also presented. Declogging - the release of fine sediment into the surface flow - is also described according to the existing literature on the subject of fine sediment transport. The clogging process is then reviewed at a larger scale with field aspects that include spatial and temporal parameters linked to flood events, sediment transport, hydropeaking and flushing of reservoirs. Finally, a synthesis of the clogging process is performed together with a dimensional analysis of key elements, followed by a discussion on the research gaps.

细泥沙是河流固体流量的重要组成部分。由于这些颗粒的大小，它们通常作为悬浮物运输。它们逐渐填充形成潜流带的基质孔隙或沉降覆盖基质，导致河床堵塞。河床主要部分的堵塞会影响无脊椎动物的栖息地，并降低产卵鱼类的繁殖成功率。在过去几十年中，大量研究报告了这种威胁。人类基础设施（如水库和水电站），加上人工河岸和一些集水区细泥沙流量的增加，已经深刻地改变了河流的动态。大量研究都集中在堵塞对水生动物的影响上。细沉积物的沉积过程也是许多研究的主题，旨在了解不同参数的作用（例如，细沉积物垂直分布对基质堵塞的作用）。本文回顾了细沉积物沉积所涉及的物理机制，以更全面地概述这一复杂过程。对过程的一般描述之后是对所涉及的不同参数的分析。详细分析了流动条件、底质成分、潜流流和细粒沉积物特征的影响。还介绍了已提出的用于估计过程的深度、数量和时间演化的不同模型。疏通——将细小沉积物释放到地表水流中——也根据关于细小沉积物输送主题的现有文献进行了描述。然后在更大范围内审查堵塞过程，包括与洪水事件、沉积物输送、水库高峰和水库冲洗相关的空间和时间参数的现场方面。最后，对堵塞过程进行了综合，并对关键要素进行了维度分析，然后讨论了研究差距。