Safety against flooding
This project is the key project of Deltares. The AIO's are being accompanied by Delft Cluster.
Click here for more information about the AIO's and their accomplished results.
Products of knowledge
|
What is it?
A soil improvement technique that strengthens sand layers in soil by means of bacteria. It involves an in-situ cementation process whereby lime crystals become ‘attached’ to sand grains. This increases the stiffness and strength of the soil whilst maintaining the permeability.
To strengthen a soil on a pilot scale, with minimal disturbance. Because permeability is maintained, it is possible to repeatedly treat soil across large distances (minimum 5 m). The process can be carried out up to any required strength (from 200kPa through to 30 Mpa), where more lime provides more strength.
Who will be interested?
Building contractors, water boards, municipalities.
More information
wouter.vanderstar@deltares.nl
hans.groot@deltares.nl
|
What is it?
A biological method to reduce soil permeability. Leaks in the subsoil can be repaired by stimulating the growth of micro-organisms. Nutrients are injected into the sol and are carried towards the leak together with the groundwater. It is therefore not necessary to know the exact location of the leak. The leak flow can be reduced by a factor of between 5 and 20 within a period of several weeks.
What can we use this for?
To seal leaks in water-retaining structures and soil layers (peat and clay).
Who will be interested?
Dike managers, water boards, municipalities.
More information
maaike.blauw@deltares.nl
john.lambert@deltares.nl
|
|
What is it?
Adapting materials and the designs of hydraulic engineering structures can help increase biodiversity in the immediate surroundings of the structure in a cost-effective way, without compromising functionality and safety. Constructing small pools in the rubble layer of sea dikes, for example, leads to a marked enrichment of the flora and fauna. A number of pilots have now been set up via a network of cooperating parties such as managers, knowledge institutes and building contractors.
What can we use this for?
To increase the recreational function of the dike environment, To increase the biodiversity of the dike environment by selecting appropriate materials and adapting the design.
Who will be interested?
Water boards, Departments of Transport, Public Works, and Water Management, harbour managers.
More information
mindert.devries@deltares.nl
|
What is it?
Interception – the temporary catchment of rainwater, for example by leaves on a tree or the upper soil layer, and the subsequent evaporation of this water – is an important process for hydrological calculations. Interception means that a substantial percentage of the rainfall, up to 40%, does not reach the subsurface. Interception evaporation accounts for approximately 50% of all evaporation. This must be incorporated into your model in order to accurately forecast the effect of rainfall on river discharge. This is not the case in many existing models, leading to an incorrect estimate of the soil’s storage capacity. If you then calculate discharge following a heavy shower, these forecasts will not be accurate.
What can we use this for?
To determine interception, field measurements are carried out under a variety of circumstances and in different seasons. Discharge forecasts after a heavy shower can now be far more accurate.
Who will be interested?
Engineering consultants, river managers, and researchers.
More information
h.h.g.savenije@tudelft.nl
|
What is it?
A flexible approach to model development, where the hydrological model is precisely adapted to the properties of a catchment basin and measurement data that have been collected. The majority of hydrological models can be described as ready-made. Although they can be adapted to all situations, their disadvantage is that they are mostly unable to accurately characterise the various processes in a specific catchment basin. It is possible to create a far more accurate model by developing it in a step-by-step way, carefully examining which process descriptions are relevant for a particular situation, and by continually checking whether a model’s forecasts match the measurement data.
What can we use this for?
Forecasts made by custom-made models provide far more accurate forecasts in catchment basins that are not too large in scale. The effect of extreme rainfall on river discharge can therefore be forecast more accurately.
Who will be interested?
Engineering consultants, river managers, and researchers.
More information
h.h.g.savenije@tudelft.nl
|
What is it?
An innovative measurement technique to measure the source of water in streams and watercourses via temperature fluctuations. The tool measures exact and minute temperature changes by reflecting a leaser beam through a glass-fibre cable.
What can we use this for?
The measurement system, a long glass-fibre cable that measures the temperature every two minutes, was initially used to determine where and how much groundwater flows out of the slope in the stream. This knowledge was necessary to validate a new rainfall-discharge model and to see how storage slopes react under extreme rainfall. The measurement technique is also suitable for other purposes, such as the detection of seepage or piping and tracing incorrect connections in separate sewer systems.
Who will be interested?
Engineering consultants, dike managers, sewer inspectors, researchers.
More information
n.c.vandegiesen@tudelft.nl
|
What is it?
A model that describes the consequences of a failed dike section on other locations within the same dike system, as well as on other dike systems. It has long been standard practice to look at the exceedance probability per dike section when determining safety against flooding. There is now a new approach that examines the probability of flooding within a dike system. The scenario approach is currently used, including in the project ‘Mapping Safety in the Netherlands’, but it does not always seem straightforward to use this approach in practice.
What can we use this for?
The model offers an alternative to the scenario approach. Use of the new working method also makes a more advanced safety approach possible, namely incorporating the effect (positive as well as negative) of an inundated dike system on the flooding probability of other dike systems.
Who will be interested?
Water boards, dike managers, municipalities, Department of Transport, Public Works, and Water Management.
More information
ton.vrouwenvelder@tno.nl
thieu.vanmierlo@deltares.nl
|
What is it?
Models to forecast the consequences of flooding and to determine the feasibility of measures aimed at reducing these consequences.
What can we use this for?
If a water-retaining structure fails, an enormous quantity of water can flow into a dike system and cause a huge amount of damage. Advanced calculation models can be used to estimate how quickly the water will spread through an area and via which routes, what the maximum water depths will be, the number of potential victims, and the economic, ecological and landscape damage that may be caused. The models can also be used when making evacuation plans and to assess measures for reducing the consequences. The knowledge that has been acquired has also been incorporated in the PAO course ‘Mapping Safety in the Netherlands.’
Who will be interested?
Water boards, disaster organisations, municipalities, Department of Transport, Public Works and Water Management, insurance companies.
More information
ton.vrouwenvelder@tno.nl
thieu.vanmierlo@deltares.nl
|
What is it?
The existing model for operational forecasting of the hydrological behaviour of the Maas catchment basin does not function as required under all hydrological situations. The model that has now been developed comprises a hydrological process model that is combined with a so-called data-driven model. This combination makes it possible to use the best properties of each model. The model has been adapted to forecast discharge from the Maas.
What can we use this for?
After the model had been thoroughly analysed, two changes were implemented. The original model elements have been replaced with Artificial Neural Networks (ANN) for several partial catchment basins, that have been trained using historical data. In addition, a ‘route scheme’ is used that is based on an ANN. The hybrid model was then optimised. The forecasting power of this optimised hybrid model is greater than that of the existing model.
Who will be interested?
Engineering consultants, river managers, researchers.
More information
d.solomatine@unesco-ihe.org
|
What is it?
A set of tools that enables storm surges to be predicted several hours in advance.
What can we use this for?
Storm surges are traditionally forecast using high-grade numeric hydrodynamic models, where the predicted wind strength, waves, and temperature are important parameters. Analysis of data from the Department of Transport, Public Works and Water Management appear to show however that water levels exhibit so-called chaotic properties, and can therefore be forecast using methods developed within the framework of chaos theory and non-linear dynamics. Experiments using such methods – adapted for the Hoek van Holland – show that the forecasts are just as good, and sometimes even better, than forecasts using ‘traditional’ models.
Who will be interested?
Department of Transport, Public Works and Water Management, researchers.
More information
d.solomatine@unesco-ihe.org
|
What is it?
A decision-supporting tool that provides information about the strength of a dike at an arbitrary river water level.
What can we use this for?
The Dike Strength Analysis Module uses coloured circles on a digital topographic map to show the probability that dike sections will fail, for both the current water level as well as the peak water level. The emergency measures that can be taken are shown alongside each circle, for example, temporary elevation of the crown, raising water channel levels, and capping sand-carrying wells. The module also indicates how often the relevant dike section should be inspected. Background information becomes visible if a user clicks on a circle, such as cross-sections, soil data, and the assumptions used when making the calculations.
Who will be interested?
Department of Transport, Public Works and Water Management, water boards, disaster organisations, municipalities, provinces.
More information
han.knoeff@deltares.nl
|
What is it?
A decision-supporting tool that town planners and dike managers can use to provide insight into the consequences of choices.
What can we use this for?
Problems frequently arise when planning construction projects on waterfronts. The dike manager will generally not want extra objects in or on the water-retaining structure, whilst town planners and project developers will by contrast prefer to build directly alongside the water. The decision-supporting tool helps town planners and dike managers to provide insight into the consequences of their choices. This offers openings for solutions where water-retention and other functions can be combined in multi-functional waterfronts.
Who will be interested?
Municipalities, water boards, project developers, provinces.
More information
b.stalenberg@tudelft.nl
|
What is it?
Until now, soil strength could only be determined in the laboratory. Soil samples must be tested in detail to do so, which is expensive and time-consuming. By using special probe heads however, soil strength can now be determined on-site. An incidental benefit is that costs can be reduced by nearly half. A concept guideline is now available for this less expensive method.
What can we use this for?
The safety factor will be determined within the Department of Transport, Public Works and Water Management’s programme ‘Strength and Loading of Water-retaining Structures’, and the definitive guideline will be developed.
Who will be interested?
Engineering consultants, water boards, Department of Transport, Public Works and Water Management, probe companies.
More information
cor.zwanenburg@deltares.nl
|
What is it?
A model that describes how softening of the clay covering due to wave overtopping can lead to more rapid damage to the inner slope of sea dikes.
What can we use this for?
If there is a large amount of wave overtopping, the dike body of a sea dike becomes saturated and the clay covering may become softer. This has been shown in centrifuge tests. Water can then flow under the clay covering via channels that are present in the dike body, such as rabbit and mouse holes, and exit via the dike toe. This may damage the clay covering with the result that the sand core becomes exposed. Once this has occurred, damage to the inner slope takes place far more rapidly. When making decisions about the degree of wave overtopping that should be allowed, dike managers can now take the quality and strength of the clay covering into account.
Who will be interested?
Department of Transport, Public Works and Water Management, sea dike managers.
More information
andre.vanhoven@deltares.nl
|
What is it?
A model that describes the various processes that occur during the failure mechanism known as ‘piping’. It has long been known that piping is one of the mechanisms that can cause a water-retaining structure to fail, but the processes that cause piping are not known. Experiments in small test set-ups have shown that the initial formation of small channels and sand transportation occur on the ‘river side’ in loosely-packed sand. This contrasts with the current theory that assumes sand transportation begins on the ‘polder side’.
What can we use this for?
This new knowledge about piping has been incorporated in the IJkdijk project when setting up the large-scale piping test. In this test, existing test rules are validated and uncertainties are (if possible) reduced or eliminated. The IJkdijk project will investigate whether it is possible to set up a piping monitoring system.
Who will be interested?
Water boards, Department of Transport, Public Works and Water Management, researchers.
More information
andre.koelewijn@deltares.nl
|
What is it?
Measures where, for example, targeted planting is used to increase water safety.
What can we use this for?
Safer dikes are possible by making use of natural components in hydraulic engineering, whilst simultaneously increasing the value of nature and the living environment. In the Noordwaard project, which forms part of the programme ‘ Space for the River’, the front bank of a dike surrounding a fort is planted with willow shrubs, for example. This vegetation has a buffering effect on waves, enabling the height of the dike to be approximately one metre lower without compromising safety. The Noordwaard case study is included in the PAO course ‘Space for the River.’
Who will be interested?
Water boards, Department of Transport, Public Works and Water Management, non-governmental organisations such as the Forestry Commission and the Nature Conservancy Board.
More information
mindert.devries@deltares.nl
|
What is it?
A training simulator for dike watchers. Dike watchers carry out dike inspections if they are threatened by extreme circumstances such as a high river water level. The aim is that they will be able to recognise any signs of damage that are a forerunner for failure of the water-retaining structure in a timely way. As these signs of damage are not visible under normal circumstances, it has been difficult to train dike watchers to recognise them until now. The training simulator makes this possible.
What can we use this for?
Dike watchers are given the task of independently inspecting several kilometers of simulated dike under extreme conditions, in an extremely realistic representation of the Dutch dike landscape. The dike watcher carries out the entire inspection process and receives feedback from the programme about the choices that have been made.
Who will be interested?
Water boards.
More information
rens.vandenbergh@deltares.nl
|
What is it?
Computer model used to calculate the stability of an underwater slope at locations with loosely-packed sand layers, which are sensitive to liquefaction flow slide.
What can we use this for?
The calculation model SLIQ2D can determine if a slope is sensitive to liquefaction flow slide in a more advanced way. The computer model can be used on a standard PC. High-grade expertise and specific soil investigation results are required to use the model. Also see product 23.
Who will be interested?
Engineering consultants, sand production/dredging companies, those issuing permits.
More information
geeralt.vandenham@deltares.nl
michiel.vanderruyt@deltares.nl
|
What is it?
Computer model that can calculate the design of a stable underwater slope based on soil investigations at production sites. It is assumed that the slope is formed by erosion and breaching.
What can we use this for?
The CUR Recommendation 113 provides general guidelines to guarantee the stability of banks at sand production pits. The calculation model HMBreach is able to investigate breaching and design the slope in a more advanced way. The computer model can be used on a standard PC. The application requires the necessary expertise.
Who will be interested?
Engineering consultants, sand production companies, dredging companies, those issuing permits.
More information
dick.mastbergen@deltares.nl
geeralt.vandenham@deltares.nl
|
What is it?
A two-dimensional morphological model of the Dutch Rhine branches based on the computer program Delft3D.
What can we use this for?
Approximately 40 projects are being carried out within the framework of the programme ‘Space for the River’. It is intended that these projects will show the consequences of river-widening measures for shipping, as well as for future maintenance and management. Does the shipping channel silt up and do the measures lead to extra maintenance? The two-dimensional morphological model of the Rhine branches has been developed for market parties to ensure that the involved engineering consultants can answer these types of questions.
Who will be interested?
Engineering consultants, those taking the initiative for river-widening measures, Department of Transport, Public Works, and Water Management.
More information
mohamed.yossef@deltares.nl
|
What is it?
A four-day course for parties involved in the preparation, implementation and management of ‘Space for the River’ measures.
What can we use this for?
The ‘Space for the River’ programme consists of a broad package of measures, intended to bring together the frequently differing interests involved. Flooding and nature objectives can often conflict for example with shipping objectives and maintenance and management aims. Among other things, this requires that all those involved have a broad insight into the dynamics of river systems and understand that each intervention affects the hydraulics and morphology. In addition to passing on knowledge, the course is structured so that participants are able to recognise the various problems and, for example, will know when they must call in the help of experts.
Who will be interested?
Municipalities, provinces, water boards, Department of Transport, Public Works, and Water Management, engineering consultants, landscape architects, building contractors, dredging companies.
More information
hendrik.havinga@rws.nl
|
What is it?
A model that describes the process of sedimentation and erosion in three periods, namely a period with freely meandering rivers, a period when rivers are enclosed by dikes, and a period in which the channel is fixed with groynes.
What can we use this for?
In the coming decades, a variety of river bed measures are on the programme during high water levels in winter. Understanding the sedimentation dynamics of the past makes it possible to accurately determine the effects of these types of measures, such as clay and sand production or the excavation of peripheral channels, and to arrive at guidelines for sedimentation management. Where can raw materials be produced with minimal damaging consequences and how, for example, can you provide space for the development of vegetation?
Who will be interested?
River managers, parties involved in ‘Space for the River’.
More information
h.middelkoop@geog.uu.nl
|
What is it?
A method for using old deposits, the so-called geological archive, to reconstruct past water levels. A shell layer, for example, was discovered in the first row of dunes close to Heemskerk that was deposited during a storm surge in 1775. With a level of 4.7 meters above NAP, it was far more extreme than that of 1953.
What can we use this for?
Water levels along the Dutch coast have already been registered in some places for 100 years. These series of measurements have been used to calculate water levels with an exceedance probability of once in 10,000 years. The geological archive offers the possibility to extend the 100-year series of measurements, and in doing so to improve the reliability of interpolating an exceedance probability of once in 10,000 years. Linking field measurements and historical data also enables numeric models to be enhanced. These models provide insight into the processes and parameters that play a role in storm surges. The impact of the morphology of the first row of dunes (the current closed first row of dunes versus a row of dunes with blow-out layers or other layers), near-shore bathymetry, and the shape of the dunes situated behind can then be examined.
Who will be interested?
Engineering consultants, coastal managers, researchers.
More information
sytze.vanheteren@deltares.nl
|
What is it?
A model that describes in great detail the physical processes that lead to the formation of dunes and ridges on the river bed.
What can we use this for?
The size of ridges and dunes on the river bed influences the discharge capacity of rivers. We can use the new model to forecast what happens on the river bed and which processes lead to dune formation. This information is needed, for example, to calculate the representative flood level for a given representative river discharge wave.
Who will be interested?
Department of Transport, Public Works, and Water Management, researchers..
More information
erik.mosselman@deltares.nl
|
What is it?
Guidelines for the design of underwater slopes during sand production, and for issuing scouring permits. Also comprises a substantiating report and ‘A look at the Future’.
What can we use this for?
The CUR Recommendation 113 provides general guidelines to guarantee the stability of banks during sand production.
Who will be interested?
Sand production companies, those issuing permits, and engineering consultants.
More information
joop.koenis@curbouweninfra.nl
secretariaat@curbouweninfra.nl
|
What is it?
A collaborative agreement between Dutch research institutes and the Water Service in the field of river morphology.
What can we use this for?
Dutch knowledge of river morphology receives an enormous boost by carefully attuning research, cooperating within projects, and jointly defining new research. The Morphological Triangle was established in 2001 as a result of cooperation within Delft Cluster.
Who will be interested?
Department of Transport, Public Works, and Water Management, engineering consultants, knowledge institutes, universities.
More information
erik.mosselman@deltares.nl
|
|
