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Improving the navigability of the Lower Old Danube in Romania
The Danube has been designated a Priority Axis, a pan-European inland transport link from the port of Rotterdam on the North Sea to the port of Constanta on the Black Sea. In Romania, the Danube covers 1075 kilometres from its point of entry at Bazias to the mouth at Sulina. Several studies have been conducted in recent years and recommendations have been made to improve the navigation conditions on the Danube between Calarasi and Braila. The aim of the present project is to evaluate alternatives for improving navigability. In order to provide sound recommendations, we developed two different models: a detailed 3D hydrodynamic model for the Bala bifurcation, and a large-scale quasi-3D morphodynamic model for the Danube branches. The models were used to simulate and analyse two scenarios for improving navigability by comparison with the benchmark condition.
New guidelines for inland waterways in the Netherlands
Waterway guidelines are key to safe, reliable, and efficient navigation in the Dutch waterways network. The present waterway guidelines are restricted to canals. In recent years, Deltares, MARIN and Rijkswaterstaat have been developing a set of rules that will allow the guidelines to be applied to the complete waterway network, including the river systems. These rules are based on the in-depth analysis of the hydrodynamic and morphological conditions, and the manoeuvrability of inland vessels. A unique combination of numerical simulations and statistical data analysis models that uses heterogeneous sources of information (about factors such as ship manoeuvring, experience from the field or physical models) ensures the best possible assessment of waterway guidelines (which include factors such as the cross-sectional profile of navigation channels, bend radius and port entrances).
Innovations in breakwater design
OCP, a global leader in the phosphate and phosphate derivatives markets, is planning a new dry bulk facility off the western coast of Morocco at Laayoune. As part of this project, Royal HaskoningDHV prepared the preliminary design of an offshore breakwater to protect the dry bulk facility. Deltares then verified stability and overtopping performance using 2D and 3D physical models which allowed the optimisation of the design of the offshore breakwater.
Optimising coastal structures with numerical modelling
The joint industry project (JIP) Coastal Foam focuses on the development of numerical tools to predict the stability of various components of coastal structures, and particularly on the open source CFD-toolbox OpenFoam. One of the studies looked at open filters in which rock material is placed on top of a sand core. Another area studied was slamming loads from breaking waves on crest wall elements.
Monitoring the quality of railway tracks from space
Subsidence can play a key role in the performance, serviceability and safety of engineering works such as railway embankments. Research by Deltares in 2007 indicated that 40% of the maintenance costs for railways in the Netherlands are linked to preserving the geometry of the railway track. Deltares developed a predictive settlement model for railway embankments built on soft soils. The main achievement of this project is the stochastic prediction of secondary settlement using satellite data and subsoil data. This prediction will improve the assessment of the quality of railway tracks in the long term and help to rationalise existing monitoring campaigns.
Bather Safety App
Deltares hosts a mobile phone application that displays forecasts of sea currents and beach widths around the Sand Motor (Delfland Coast, the Netherlands). The information is consulted by the lifeguards responsible for monitoring bather safety at the Sand Motor. It allows them to anticipate potentially dangerous situations on the beach and in the shallow waters such as rip currents. Precautionary measures can be taken to reduce the risks for visitors to the beach.
The added value of passive sampling in the monitoring of organic pollutants
Good and effective monitoring of water quality is key to determining whether, and where, measures should be taken to improve water quality. Monitoring for organic pollutants can be performed with passive sampling. A sampler with sorption material is exposed to water for several weeks or months. During the exposure, organic pollutants are sampled by diffusion from the water, resulting in a time-integrated average concentration based on large sampled volumes. In recent years, Deltares has further developed the technique and applications in a range of water types such as sewage water, surface water and groundwater.
A fresh look at effective river restoration
The assessment of the First River Basin Management Plans conducted in the context of the Water Framework Directive (WFD) indicated that 40% of European rivers are affected by hydromorphological pressures that are caused predominantly by hydropower, navigation, agriculture, flood protection and urban development. A consortium of 26 partners coordinated by Deltares was therefore established to generate substantial output as part of the REFORM project (REstoring rivers FOR effective catchment Management) to support the implementation of the Water Framework Directive.
Quantifying the long-term effects of human interventions on estuarine sediment concentrations
Many estuaries worldwide have been modified in recent decades and centuries, for example through land reclamation or to allow ever larger ships to access inland waterways. These human interventions often lead to higher suspended sediment concentrations (SSC), which reduce visibility and lead to a decline in primary production at the base of the ecological food chain. One estuary affected in this way is the Ems Estuary on the Dutch-German border. Deltares has quantified historical changes in SSC associated with human interventions and advised on mitigating measures.
Recovery of Adelaide’s seagrass meadows
Seagrass has been disappearing from Adelaide’s coastal waters in the Gulf St Vincent, South Australia since the 1950s. The Adelaide Coastal Waters Study concluded in 2007 that the seagrass decline was caused by discharges of treated sewage, rivers and storm water, which reduce water transparency and further the excessive growth of “epiphytes” on the seagrass leaves. Both phenomena reduce the amount of sunlight penetrating to the seagrass leaves and subsequently kill the seagrass. At that time, however, it was not clear when, where, and by how much these discharges would need to be reduced to create the conditions required for recovery of the seagrass meadows. The South Australian Water Corporation (SA Water) commissioned Deltares to jointly develop coastal modelling capabilities that would help to answer these questions. With Delft3D as the main “engine”, SA Water, Deltares and DAMCO Consulting (Perth, West Australia) built the Adelaide Receiving Environment Model (AREM).