Mussel beds are important biogenic structures in the intertidal and subtidal environment of the (Dutch) Wadden Sea. Mussel beds are partly able to stabilize the substrate of the Wadden Sea, to improve the water quality, to establish important habitats for many (benthic) species and to provide food for water birds and other organisms. The coastal research group of Utrecht University will focus on the physical/hydrodynamical processes and conditions that can play a decisive role in the development of stable mussel beds. read more

Nearshore sandbars often exhibit remarkable alongshore-periodic undulations in their height and cross-shore position. These so-called crescentic sandbars are characterised by horizontal flow patterns with rip currents. During storm periods, the sandbars are almost immediately straightened again due to strong undertow currents. In double-barred systems, the shape of the outer bar may govern the evolution of the inner bar, introducing coupled patterns. In this project field observations (video images) and numerical models are combined to determine the conditions under which the outer crescentic sandbar (a) controls the morphology of the inner bar and (b) is reshaped into a shore-parallel linear bar. read more

The wave and current flume of the laboratory for physical geography is a flume for studying waves and currents in a controlled environment. The flume is available for educational purposes and research. Academic research experiments can be performed at low costs, and secondary school experiments are free of charge. read more

Bifurcations distribute water, sediment and contaminants over distributaries in deltas. The aim of this study is to develop and test a bifurcation stability model for time-scales of 10¹-10³yr, in which water and sediment is distributed depending on both local (e.g., meandering, bifurcation planform) and regional controls (e.g., climate, base-level). Bifurcations are key elements in delta evolution on time-scales of 10²-10³yr and river flooding mitigation on time-scales of 10¹-10²yr. read more

Nearshore sandbars (alongshore ridges of sand in 2 - 10 m water depth typical of microtidal, storm-dominated coasts) serve as a natural protection for beaches by causing waves to break away from the shoreline. Cross-shore sandbar behavior is governed by the feedback between nonlinear hydrodynamics, sediment transport and the sandbar itself. Predictions of sandbar behavior with sophisticated numerical models are inherently uncertain because of a sensitive dependence on initial conditions and model inadequacies. This project aims to quantify these uncertainties and to determine its relevant source by means of embedding the traditional single-forecasts in a probabilistic (ensemble) environment and ensemble data-assimilation techniques. read more