Modulation of sediment load recovery downstream of Three Gorges Dam in the Yangtze River

The sediment load in the Yangtze River downstream of the Three Gorges Dam (TGD) has substantially declined in recent decades. The decrease is more profound below the TGD, e.g., a 97% decrease at Yichang, compared with that at the delta apex, 1200 km downstream, e.g., a 75% decrease, implying along-river sediment recovery. Two large river...

Impact of Reduced Fluvial Sediment Supply on Saltwater Intrusion in the Yangtze Estuary

A decline of the fluvial sediment supply leads to coastal erosion and land loss. However, the fluvial sediment load may influence not only coastal morphodynamics but also estuarine hydrodynamics and associated saltwater intrusion. Previous studies revealed that suspended sediments influence estuarine hydrodynamics through various flow...

Feedback Effects of Sediment Suspensions on Transport Mechanisms in an Estuarine Turbidity Maximum

The mechanisms controlling the formation of an estuarine turbidity maximum (ETM) in estuaries have been extensively investigated, but one aspect that has received much less scientific attention is the role of high suspended sediment concentrations in combination with tidal asymmetry in ETM formation. Particularly in highly turbid estuaries,...

Anthropogenic effects on the hydro-morphological development of turbid estuaries

Estuarine sediment dynamics involves estuarine hydrodynamics, sediment transport, and morphology, and strongly influence ecosystem dynamics and sustainability. In the current geological epoch, referred to as the Anthropocene, human activities are exerting increasing impacts on the environment on all scales, changing hydrodynamics, sediment...

Effects of Sediment-Induced Density Gradients on the Estuarine Turbidity Maximum in the Yangtze Estuary

An estuarine turbidity maximum (ETM) is a region of elevated suspended sediment concentration (SSC) resulting from residual transport mechanisms driven by river flow, tides, and salinity-induced density gradients (SalDG). However, in energetic and highly turbid environments such as the Yangtze Estuary, SedDG may also substantially contribute...

Salt marsh establishment in poorly consolidated muddy systems: effects of surface drainage, elevation, and plant age

Conservation and restoration of salt marsh ecosystems are becoming increasingly important because of the many ecosystem services they provide. However, the processes controlling salt marsh establishment and persistence, especially on bare tidal flats in muddy areas, remain unclear. As muddy sediments typically experience a restriction of soil...

Changjiang Delta in the Anthropocene: Multi-scale hydro-morphodynamics and management challenges

The Changjiang Delta (CD) is one of well-studied large deltas of critical socio-economical and ecological importance regionally and global representativeness. Cumulated field data and numerical modeling has facilitated scientific understanding of its hydro-morphodynamics at multiple spatial and time scales, but the changing boundary forcing...

Regime shifts in the Changjiang (Yangtze River) Estuary: The role of concentrated benthic suspensions

Channel deepening often triggers positive feedback between tidal deformation, sediment import and drag reduction, which leads to the regime shift in estuaries from low-turbid to hyper-turbid state. In this study, a transition in profiles of suspended sediment concentration (SSC) is hypothesised by including a positive feedback loop of...

From the headwater to the delta: A synthesis of the basin-scale sediment load regime in the Changjiang River

Many large rivers in the world delivers decreasing sediment loads to coastal oceans owing to reductions in sediment yield and disrupted sediment deliver. Understanding the sediment load regime is a prerequisite of sediment management and fluvial and deltaic ecosystem restoration. This work examines sediment load changes across the Changjiang...

How have the river discharges and sediment loads changed in the Changjiang River basin downstream of the Three Gorges Dam?

Streamflow and sediment loads undergo remarkable changes in worldwide rivers in response to climatic changes and human interferences. Understanding their variability and the causes is of vital importance regarding river management. With respect to the Changjiang River (CJR), one of the largest river systems on earth, we provide a...

Breach growth in clay-dikes

Numerous flood disasters occur every year worldwide, mostly resulting from failure of dikes, some with catastrophic outcomes. Examples are the dike failures along the Yangtze River in China in 1931 due to heavy rainstorms and those in the Netherlands in 1953 due to a storm surge at the North Sea. Both floods induced many deaths and enormous...