Peak Water Levels Rise Less Than Mean Sea Level in Tidal Channels Subject to Depth Convergence by Deepening

Effects of sea-level rise (SLR) on future peak water levels in tidal deltas and estuaries are largely unknown, despite these areas being densely populated and at high risk of flooding. While the rates of SLR accelerate, many channels simultaneously experience channel deepening for navigation. With globally decreasing sediment supplies, most...

Morphodynamic Modeling of Tidal Basins: The Role of Sand-Mud Interaction

The morphology of tide-dominated systems is progressively influenced by human activities and climate change. Quantitative approaches aiming at understanding or forecasting the effects of interventions and climate change are often aggregated, thereby simplifying or schematizing the investigated area. In this work, we advance on the knowledge...

Sensitivity of salt intrusion to estuary-scale changes: A systematic modelling study towards nature-based mitigation measures

Estuaries are among the most densely populated and heavily utilised regions in the world, where crucial functions – e.g., freshwater availability and water safety – strongly relate to the natural dynamics of the system. When developing nature-based solutions to safeguard these essential functions, a thorough understanding of estuarine...

Drivers of residual sediment transport in a stratified estuarine channel

The bed stability of an estuary is determined by the net import or export of sediment, which in turn is controlled by multiple processes. Apart from the upstream riverine sediment supply, the net sediment flux is largely controlled by tidal hydrodynamics and the associated sediment exchange with the sea. In general, flood dominance causes...

Salt Intrusion Around the World Under Influence of Climate Change

We investigate the changes in surface water salinity intrusion lengths for estuaries around the world under influence of climate change. To do this, we make use of information from global data sets on present river geometry and present and predicted future river discharges, mean sea levels and tidal ranges, which we combine with various models...

Development of intertidal flats in the Dutch Wadden Sea in response to a rising sea level: Spatial differentiation and sensitivity to the rate of sea level rise

The Wadden Sea is a unique intertidal wetland area, forming an important hub for migratory water birds. A feared effect of accelerated sea-level rise (SLR) is the gradual loss or even disappearance of the ecologically valuable intertidal flats. To date, the effect of SLR on the time-evolution of the intertidal areas in the Dutch Wadden Sea...

Future sediment exchange between the Dutch Wadden Sea and North Sea Coast - Insights based on ASMITA modelling

The sediment exchange between the Dutch Wadden Sea and the North Sea coastal zone is of key importance to Dutch coastal management. Net sediment import from the coastal zone to the Wadden Sea results in coastal erosion which needs to be compensated through nourishments. At the same time net sediment import is the source of sediment for the...

The Existence and Origin of Multiple Equilibria in Sand-Mud Sediment Beds

The sediment composition of the seabed governs its mobility, hence determining sediment transport and morphological evolution of estuaries and tidal basins. Bed sediments often consist of mixtures of sand and mud, with spatial gradients in the sand/mud content. This study aims at increasing the understanding of processes driving the sediment...

Lithological control on scour hole formation in the Rhine-Meuse Estuary

River deltas commonly have a heterogeneous substratum of alternating peat, clay and sand deposits. This has important consequences for the river bed development and in particular for scour hole formation. When the substratum consists of an erosion resistant top layer, erosion is retarded. Upon breaking through a resistant top layer and...

Tidal controls on river delta morphology

River delta degradation has been caused by extraction of natural resources, sediment retention by reservoirs, and sea-level rise. Despite global concerns about these issues, human activity in the world’s largest deltas intensifies. Harbour development, construction of flood defences, sand mining and land reclamation emerge as key contemporary...

The development of scour holes in a tidal area with heterogeneous subsoil under anthropogenic influence

Variable flows and fast morphological changes characterize the river system of Bangladesh, which includes the downstream reaches and delta of the Ganges and Brahmaputra rivers, two of the largest rivers in the world. In contrast, fresh water supply around the country largely depends on much smaller distributaries that take off from those large...

Dispersion and dynamically one-dimensional modelling of salt transport in estuaries

An estuary forms the transition between the  ocean/sea and a river and within its boundaries  fresh and salt water mix. Fresh water intake  points may be located within the reach of salt  intrusion. In order to justify political and  managerial decisions it is thus necessary to  understand and be able to predict...

Optimising long-term morphodynamic simulations of the Rhine-Meuse Delta (abstract)

Computational effort still poses serious limitations to practical use of 2D and 3D models for long-term largescale morphological modelling. To deal with long-term issues related to sea-level rise and long-term planning in the Dutch Rhine delta, we have adapted the computational approach for more efficient and fast modelling while including all...