2. CONTENTS
NEWS
Our Common Delta • Delft-FEWS pilot in
Australia
> page 4
• Upgrade your knowledge
• Advanced laboratory
research Fehmarn Belt
The fundamental • Delft hosts first
importance of International Conference
morphological research on Frontiers in Shallow
to coastal and river Subsurface Technology
management
> page 24
The shape of
things to come
> page 6
PhDs
• Trends in groundwater
Integrated coastal zone quality in relation
management in Suriname to groundwater age
From mud bank • Bridging Boundaries:
to mangrove Making scale choices in
multi-actor policy analysis
> page 10
on water management
• Dune erosion during storm
Bacteria to replace piling India: surges
Dutch polders Maasvlakte 2: Delta Alliance: SmartSoils : ®
bare essentials • Satellite data as
in Louisiana Port expansion in a problem shared changing soil of groundwater complimentary information
marshlands? the 21st century is a problem halved properties to order management for hydrological modelling
> page 13 > page 14 > page 18 > page 19 > page 22 > page 26
4. Coastlines and river basins change shape all
The fundamental importance of morphological the time. Sometimes the changes are sudden
research to coastal and river management and dramatic, resulting from extreme events like
hurricanes or tsunamis. More often, they are
The shape
USA and Indonesia
the gradual result of complex processes of erosion
and sedimentation. We still know relatively little
about morphological processes but advanced computer modelling is providing
new insights.
of things In 2005, Deltares researcher Deepak Vatvani travelled
to Indonesia to produce a computer model capturing
so much research is being conducted on coastal mor-
phology in countries like the US. Deltares researcher
to come
the origins, development and impact of the tsunami Dano Roelvink, Professor of Coastal Engineering and
that devastated the coast of Sumatra in the closing Port Development at UNESCO-IHE, talked to us about
days of 2004. The model he made not only forms cooperation with the US Geological Survey (USGS).
the basis of a Tsunami Early Warning System (see “We are cooperating with the USGS on modelling
box on page 8), but also provides new information hydrodynamics, sediment transport and morphology
about the relationship between tsunamis and coastal in various coastal areas. In general, the USGS possess-
morphology. And that is extremely welcome. es the necessary data – often in impressive amounts
– while Deltares can offer the modelling software and
Process of change expertise. In tidal inlets along the west coast, for ex-
”We used Delft3D software to model the origins and ample, there is a problem with the migration of gullies
development of the tsunami”, Vatvani explains. “We and sandbanks, which causes parts of the coastline to
show how the tidal waves changed the coast and where erode. Rather than build endless hard coastal defences,
the coast is now vulnerable to future inundation. This the USGS prefers to get to the root of the problem and
information provides a crucial basis for the design of look for an appropriate solution. In Florida we’re busy
new coastal defences and future evacuation routes.” charting hurricane impacts. Whatever the approach, >>>
The coastline of Aceh province was dramatically
altered by the 2004 tsunami. New areas of land have
emerged from the sea, while others have vanished
under the waves. The tsunami may seem like a single
one-off event but, as Vatvani explains, it is actually XBeach
part of a continuing process of change. “Underneath
the Indian Ocean, two continental plates are sliding Dano Roelvink is putting a lot of time into the develop-
over each other. The friction produces earthquakes ment of XBeach, a new model designed to calculate storm
and water motions. Various studies have shown that impacts like dune erosion, overwashing and breaching
a tsunami like the one in 2004 occurs once in every of sandy coasts. ;“To approximate to the complexity of
five hundred to a thousand years. So the morphology a coastal system, you have to include all the relevant
of the coastline, including the processes of erosion physical parameters in your model. That’s what we can do
top: Colorado River, USA • bottom left: Deltares researcher Dr Kees Sloff • bottom right: Disappearing beaches and sedimentation occurring along it, likewise under- and we’re working hard on it. XBeach is one of the latest-
goes dramatic change at those intervals. And that has generation models, which are able to replicate a variable
knock-on effects on the development of the coast over coast, differing storm conditions and combinations of hard
the next few centuries. If we want to manage the coast and soft coastal elements. It was initially developed by
in a sensible, sustainable way, it’s important to get UNESCO-IHE, Delft University of Technology, the University
a better understanding of such long-term processes. of Miami and Deltares, on the initiative of the US Army
And that’s what we’ve started to do.” Corps of Engineers. Because it’s an open source application
in the public domain, a multitude of partners are now
Getting to the root of the problem working on it, including the USGS, so we should ideally end
Worldwide, little is known about the influence either of up with a universally – or, at any rate, widely – applicable
extreme events or of longer-term processes of erosion coastal model. The more input we get the better.”
and sedimentation on coastal morphology. This is why
6 Deltares VIEWS Nº 2 Deltares VIEWS Nº 2 7
5. >>>
you need extensive knowledge of the coastal system to like sea level rise or, indeed, the consequences of hu- data at the invitation of the USGS. It was a memora-
arrive at an appropriate solution. We’re making big ad- man interventions like major hydraulic engineering ble trip. “Imagine sailing into the Grand Canyon on
vances in the modelling of morphological processes.” works or sand nourishment off-shore or in a gulley. rafts loaded with monitoring apparatus and spending
a week bivouacking there with geographers, environ-
Fresh air mental experts and water management experts. It was
Roelvink finds the vast quantity of local data pos- “If we want to manage the coast a real adventure.”
sessed by the USGS a breath of fresh air. “We have a
lot to offer each other. Our modelling tools enable the
in a sensible, sustainable way, But why were they there? In the mid-sixties, the Glen
Canyon dam was built upstream of the Grand Canyon.
USGS to get a better understanding of the US coast, it’s important to get a better The dam halted the supply of sediment from the
while their research teaches us more about phenome-
na we also face in The Netherlands. For example, we are
understanding of such long-term Colorado River. Not just that, but the hydroelectric
power plant at the foot of the dam reduced the natural
keen to know what sort of damage would be inflicted processes” flow of water. Since then, the river in the Grand Canyon
on our coastal dunes by a storm likely to occur on the has received sediment only from minor tributaries.
Dutch coast on average once in every ten thousand Because we are only now starting to realise the range “The process by which sandbanks and beaches in the
years. Well, the USGS studies the hurricanes that hit of potential impacts of sand nourishment, on every- canyon were washed away by peak discharges and
the American coast every year and they have the same thing from flora and fauna right through to the safety then laid down again, was lost”, says Sloff, “and what’s
sort of magnitude and impact.” of bathing water. Scientific progress benefits us all.” left of them is now disappearing.” The small sandy
At the same time, USGS data and research benefit model beaches play a crucial role in the natural ecosystem:
development in general. “The many different kinds of Colorado River they provide a habitat for specific species of flora and
monitoring data they collect help to validate the mod- This fruitful partnership is not confined to coastal mat- offer quiet places for young fish to grow. They are also
els. The better a model can replicate the natural sys- ters. In March 2008, Deltares researcher Kees Sloff vital to campers and rafters making their way through
Post-Katrina aerial photograph of Dauphin Island, Alabama, USA tem, the better we can anticipate long-term processes sailed down the Colorado River collecting monitoring the Canyon. “In 1996 a controlled surge was sent down
Source: USGS/NASA this stretch of the river. The idea was to stir up the
bottom sediments delivered by the tributaries at just
the right moment to trigger the desired process. The
measure was repeated in 2004 and 2008.”
Tsunami Early Warning System Research
The key question is what strategy will produce the
best results. Would it help to open the sluices? And, if
so, when and for how long? The extensive monitoring
At 7.01 a.m. on 26 December 2004, an earthquake occurred beneath thing occurring again? And what system will compare its strength focused on the areas genuinely at campaign was intended to answer such questions. “We
the bed of the Indian Ocean. Twenty minutes later, a layer of water would be the consequences if and location with the model situ- risk. The response time is short; spent a whole week taking detailed measurements of
five metres high reached the Indonesian province of Aceh, situated it did? Vatvani: “We know very ation and the expected impact people have less than twenty everything from bed topography to flow rate”, says
at the western tip of the island of Sumatra. The ocean receded little about tsunamis. To help scenario will appear on the screen minutes to get out.” All the better, Sloff. “The USGS collected a huge quantity of data to
temporarily and then rushed back to swamp the coast under a tidal us make better estimates of the in seconds. At the places along the then, if efforts can be concentrat- enable it to determine how the system works and what
wave ten metres high. The tsunami claimed the lives of almost risks associated with them, we’ve coast where the threat is greatest, ed where they are most needed. processes are involved.” But the USGS wants more than
200,000 people in Aceh. collected together and further ex- sirens will start to sound.” Vatvani says that, not long after just monitoring data. Modelling information is an impor-
panded all the model calculations the tsunami of 2004, there was an tant tool for the development of a sophisticated water
Deepak Vatvani sits at his laptop BRR, the Aceh-Nias Rehabilitation we made for the reconstruction.” Panic avoidance under-sea quake with a magni- management strategy. “We are helping them model all
and runs a simulation of the and Reconstruction Agency, we set An existing early warning system The new insights into the con- tude (Mw) of 8.7. The alarm was the processes that determine how sand enters and exits
tsunami. The tidal wave spreads to work on a reconstruction of the shows whether an earthquake will sequences of tsunamis make it sounded throughout the entire the canyon. From the very local interaction between a
out over the ocean like spilled wine tsunami.”Deltares modelled the result in a tsunami. But it doesn’t possible to conduct a proper risk region and a million people were rapid and the pool behind it right through to the entire
soaking into a tablecloth. Arriving development of the wave following say how high the tidal wave will be analysis. For instance, the new evacuated. “But if you’re in a ‘wet water flow.” Once again, both sides are learning from
at the coast of Aceh, it continues the earthquake and produced a and which particular areas will be TEWS shows that no evacuation feet zone’, where the water won’t the exercise. “Absolutely. Here in The Netherlands, we
its unrelenting course, reaching simulation of the inundation of engulfed. That gap has been filled will be necessary in the case of get deeper than 30 cm, there’s encounter similar small-scale interactions, for example
several kilometres inland. Banda Aceh, the capital of Aceh by coupling the database con- an earthquake measuring 7 on no need to flee. With the ‘Dutch’ in groyne fields along the major rivers. Greater knowl-
“Following the disaster, various province. “Comparison with satel- structed by Vatvani to the early the moment magnitude scale. TEWS installed, the authorities edge of this phenomenon is extremely welcome. And
government projects were lite images shows that the simula- warning system. (Seismologists believe that the could have sent out differentiated this is high-quality research: the wealth of monitoring
launched in the Netherlands”, tion results approximate closely to “The crux of the new Tsunami December 2004 earthquake had warnings and avoided panic and data, the research on the best possible way of modelling
Vatvani explains. Together with what actually happened.” Early Warning System (TEWS) is a magnitude of 9.1 on that scale, disruption.” morphological processes… it’s cutting edge stuff.”
two partners, Deltares set up the the coupling of earthquake-related although tsunami experts think
Sea Defence Consultant consor- Coupling data to a water motion model. it was 9.3.) “It means that, in a For more information: deepak.vatvani@deltares.nl,
tium (SDC). In consultation with How great is the risk of such a If another earthquake occurs, the real-life emergency, efforts can be dano.roelvink@deltares.nl, kees.sloff@deltares.nl
8 Deltares VIEWS Nº 2 Deltares VIEWS Nº 2 9
6. Integrated coastal zone management in Suriname
From mud bank
to mangrove
The flat coast of Suriname is a succession of mud banks,
mangrove swamps and narrow beaches that stretches from the
Corantijn River in the west to the Marowijne River in the east.
Large sections are still pristine, but the coast is under attack.
Suriname
Human activities threaten its natural morphodynamic processes.
Transport by boat in Suriname
It is vital to strike a balance between economic and banks. “The Surinamese and Dutch coasts have more plan, part of the job is to conduct a stakeholder analy- at a particular section of the coast or at particular
ecological interests and find a way of rhyming coast- in common than you might think”, explains Marcel sis. As Bucx explains, representatives of ministries, issues, like coastal development or the protection of
al protection with coastal development. With this Marchand. “Both are low-lying, at high risk of inunda- knowledge institutions and civil society organisations mangrove swamps, taken in isolation. But it’s better to
in mind, the Ministry of Planning and Development tion, and highly dynamic: in other words, both coast- have provided input during interviews and workshops. consider such issues in relation to each other. Things
Cooperation has commissioned the preparation of an lines are naturally extremely mobile. Deltares has a “We are using their input to check and supplement like spatial planning and flooding, for instance. And
Integrated Coastal Zone Management Plan (ICZMP). lot of in-house expertise concerning low-lying coastal that’s what we’re doing now.”
zones and their problems.” [See box on page 12] Given such a broad subject area, it’s hardly a sinecure.
A consortium of local and international experts is “This is the first time that As Marchand points out, “Just defining the problem is
involved in the project, which is headed by Lievense
Consulting Engineers. Deltares consultant Marcel
Integration
Under The Netherlands Climate Assistance Programme
all the issues to do with difficult: for instance, where do you place the limits of
the coastal zone?” And there are factors in each of the
Marchand is largely responsible for the preparation of (NCAP), research was done in the late ’90s on the living and working in the various districts that complicate the preparation and
a plan for the entire coastal zone, while another ICZM
consultant, Tom Bucx, is focusing on a sub-plan for the
vulnerability of Suriname and possible consequences
of climate change for the country. Follow-up studies
coastal zone are being implementation of an ICZMP. Marchand cites examples
like over-fishing and the upstream gold mining that
densely populated districts of Paramaribo and Wanica. were performed between 2005 and 2008. The NCAP dealt with together” leads, via the rivers, to mercury pollution on the coast.
They are working hand in hand with a team of ex- recommended the development of integrated coastal A total of 25 issues are vital enough to require fur-
perts in ecology, morphodynamics and morphology, zone policies and also the production of a Master Plan ther investigation. Marchand: “It isn’t easy to ensure
social economics, and urban development. Colleague for the Drainage of Greater Paramaribo. This plan was our own findings and to help pinpoint priorities. At the that the plan does justice to all these aspects. But it’s
Paul Erftemeijer is concerned primarily with the im- produced in 2002 with the assistance of what was then same time, involving stakeholders ensures public sup- important to mention them all, including the gaps in
portance and regeneration of the mangrove swamps, Delft Hydraulics. The NCAP I and II reports are being port for the plan.” current knowledge.”
while Han Winterwerp is advising on morphodynam- used as input to the present ICZMP. So what is the
ics. Their participation is hardly surprising: Deltares added value of the ICZMP? Tom Bucx: “The measures Complex Master plan
has been involved in coastal research in Suriname ever proposed in the earlier reports were frequently global in The unique thing about this project is its scope. The ICZMP will pay special attention to the districts of
since the 1960s, when the Waterloopkundig Labora- nature; we are firming them up in order to arrive at an Marchand: “This is the first time that all the issues Paramaribo and Wanica. That is where the problems
torium (later known as Delft Hydraulics and now part adaptation strategy.” Since it is extremely important to do with living and working in the coastal zone are are most pressing, particularly in relation to popula-
of Deltares) conducted research on the offshore mud to involve all the stakeholders in the development of the being dealt with together. Earlier studies just looked tion. Two-thirds of the country’s population live in >>>
10 Deltares VIEWS Nº 2 Deltares VIEWS Nº 2 11
7. Dutch polders
>>> those areas and coastal development is sometimes too early 2010. Marchand thinks this is a step in the right
close to the sea. Where mangrove forests have direction but “Integrated coastal zone management is
been cleared, the risk of coastal erosion increases. not a project; it’s a process that takes years. This is just
in Louisiana marshlands?
Recommendations will therefore include the estab- one part of that process.”
lishment of a natural buffer zone several kilometres There will soon be a framework document to provide
wide. “Some people won’t like it”, Bucx admits, “but guidelines for further development. “Suriname still
it’s a cheaper, more sustainable and more ecological has a lot of land available and that means that there
solution than measures like dike-building, especially is scope to choose between alternative approaches.
in the long term. This way we can plan for balanced Dikes are one possibility, of course, but a buffer zone Set in the Mississippi Delta, New Orleans is a vulnerable city in a sensitive
economic development while preserving ecological is also an option. An even better one is making use of environment. Human interventions, including the building of flood control structures
values. Which is what the government of Suriname natural processes to ‘build with nature’. Government along the river, have produced subsidence and erosion in the surrounding marsh-
asked for.” Another part of the solution is further recognises the importance of this but it takes time to lands. Vegetation is disappearing and unique wildlife areas are being lost, together
implementation of the Master Plan for the Drainage get round to implementing plans in practice. In twenty with an important buffer against storm surges. The tide needs to be turned, but how?
of Greater Paramaribo (in particular, catch-up mainte- years’ time, Suriname may be a textbook example of
nance of the drainage system). There are also plans to balanced coastal zone management.”
construct new pumping stations and build a ring dam
and canal. Such measures should end the frequent For more information: marcel.marchand@deltares.nl left:
flooding that afflicts the capital. or tom.bucx@deltares.nl Louisiana
marshlands
Long-term process right:
The sub-plan for Paramaribo and Wanica is almost Field trip by
the research
finished and the entire ICMZP should be complete by
team
“Integrated coastal zone management is not a project;
it’s a process that takes years”
“For example, by restoring the tion are leading to a rapid diminu- swamp, peat is formed or sediment
Vulnerable coast marshlands south-west of the tion of the wetland area. This is is retained so that the polder area
city.” Deltares ecologist Bregje van worrying because large stretches of is naturally restored to its old level,
Suriname is a South-American country wedged Wesenbeeck is involved in planning wooded swamps have the ability to equal to that of its surroundings.”
between French Guiana, Guyana and Brazil. sustainable coastal flood defences absorb a lot of storm surge water.
Its coast is extremely dynamic. Sediments from for New Orleans. In the wake of Besides, they are enormously valu- Buffer
the Amazon form offshore mud banks that the hurricane Katrina flood disas- able wildlife areas with an impor- Once a healthy swamp has devel-
stretch for tens of kilometres and migrate at ter of 2005, various Dutch water tant role in the area’s culture and oped in the subsidence-affected
a speed of around 1.5 km a year. These fluid experts offered their help. “Our history.” areas, the link with the surround-
mud layers damp out wave energy and produce Dutch experience with integrating ing marshland can gradually be
temporary coastal accretion. Between the mud natural processes and materials Impoldering restored by removing the dikes.
banks, however, there is a risk of coastal erosion into hydraulic engineering projects National government is taking A healthy wetland zone of suffi-
and inundation. Accretion and erosion occur in and coastal flood defences can pro- measures to combat the subsid- cient size will eventually be able
approximately 30-year cycles. House-building vide a solution in this situation. We ence. One is to re-open the swamps to sustain itself and act as a buffer
close to the coast is not advisable. call it ‘building with nature’.” to sediment-rich river water. “The against storm surges. “Healthy
Human activities are increasing the risk of ideal would be to restore the natu- natural surroundings make the city
coastal erosion, especially in the densely Worrying ral dynamics of the marshlands. less vulnerable”, says Bregje, “and
populated districts of Paramaribo and Wanica. The Mississippi flows through typi- We decided that temporarily im- the nice thing is that nature will do
Mangrove swamps Mangrove swamps are a natural form of coastal cal delta landscape. From freshwa- poldering areas of open water most of the work for itself.”
defence but urban development is nibbling away ter to salt. From swamp woodlands would give the swamps a chance
at this buffer. Wherever the sediment-retaining full of vast trees to grassy wetlands to develop in the most natural pos- For more information:
mangroves disappear, coastal erosion increases. nearer the coast. “The marshes are sible way. Sophisticated control of bregje.vanwesenbeeck
In the longer term, moreover, Suriname faces the in a poor state”, says Bregje. “Innu- water levels can be used to encour- @deltares.nl
risk of inundation as a result of rising sea levels. merable little drainage canals, peat age the growth of marshland veg-
compaction and lack of sedimenta- etation. Depending on the type of
12 Deltares VIEWS Nº 2 Deltares VIEWS Nº 2 13
10. The Mekong Delta.
Bacteria to replace piling
SmartSoils : ®
changing soil
focus attention on the integrated,
sustainable development of delta
areas. The main emphasis will be
on integrated water and coastal
properties to order
management, food supplies, urban
development, spatial planning and
climate change. The Delta Alliance
intends to encourage international
exchanges and the development of
relevant science and technology,
while at the same time stimulat-
Delta Alliance: ing and supporting the application Delta soils are frequently composed of relatively
of these in policy and administra-
young geological materials like sand, clay and
a problem shared tion. The network will therefore
include not only universities and
other knowledge institutions, but
peat. Since these materials are soft and damp,
they are far from ideal building ground.
is a problem halved also government authorities, engi-
neering companies, consultancies,
NGOs and civil society groups.
Europe Road and railway subsidence is a constant
danger and dikes weakened by piping can
The basis for the Delta Alliance has suddenly collapse. Over the last decade, Deltares has been working with
The Mekong Delta and San Francisco Bay are around 12,000 km apart. now been established. Partners in
national and international partners to develop innovative, sustainable
Similarly, the distance between the Rhine estuary in The Netherlands and four key deltas in the Netherlands,
the mouth of the Ciliwung on Java (Indonesia) is over 11,000 km. And yet Indonesia, Vietnam and the US techniques for modifying the properties of soil: SmartSoils.
these places are closely related: wherever great rivers approach the sea, (organised in Chambers) are now
they create fertile, densely populated deltas. busy formulating their views on
Alliance activities and possible
research projects. The partners BioSealing and BioGrout are two promising applica- remembers how the research was begun by Deltares,
Landscapes, peoples and cultures priorities, encouraging research, will be expected to make an active tions in which bacteria play a leading role. ‘Fed’ the Delft University of Technology and building contractor
may differ, but delta-dwellers exchanging experience and sharing contribution to the network’s right dose of nutrients, they can seal leaky dikes or Visser en Smit Bouw in 1999. “The idea came up of
around the world face the same knowledge. By working together to finances and activities, possibly strengthen soil – on site, with no onerous earthmoving using naturally occurring soil bacteria to look for and
problem: how to strengthen these address common problems they to be matched from international operations. The idea of getting bacteria to do the heavy repair leaks. Given the right kind and amount of nutri-
vulnerable areas. There is no com- can produce solutions helpful to sources. work has not come out of the blue. In the environmental ents, they multiply and produce deposits around the
mon blueprint for deltas worldwide. more deltas than just their own. geo-technology field, bacteria have long been used leak. Lab work showed that BioSealing was an effective
But the consequences of climate For more information, please to clean up contaminated soils. This made Deltares system. We experimented with different materials and
change, as well as demands for International network contact the Delta Alliance researchers wonder whether they could also be used rates of flow. It was a process of trial and error. With few
food, safety, space and economic Following the Aquaterra Forum on Project Officers: to strengthen soils or make them less permeable. This errors, because in every case the result was to stop the
viability have to be faced. The in- Delta & Coastal Development, held katherine.trajan@wur.nl or would make it possible to build in places where soft leak. So we could soon start scaling up the tests.”
terests of the human population in Amsterdam in 2009, a number cees.vandeguchte@deltares.nl or unpredictable subsoils currently prevent it. Or to
have to be reconciled with those of of Dutch organisations have de- or visit: www.delta-alliance.org carry out remediation work without disturbance (for From lab to field
nature. Everywhere, then, difficult cided to establish an international example, under existing buildings or infrastructure). BioSealing is now a fully tried and tested procedure.
choices have to be made; every- knowledge platform and partner- In 2004 a successful pilot was run on the Maasvlakte
where, a balance has to be struck ship. This Delta Alliance is due to (Netherlands) and this led to a patent application.
to keep life in the delta safe and go into official operation in 2010. Biosealing: making soil watertight Lambert: “On the Maasvlakte, we buried three leak-
productive. Decisions and meas- It aims eventually to expand into ing shipping containers and administered nutrients to
ures need to have a firm knowl- an international network of delta- It was leaks occurring in the course of projects like the bacteria naturally present in the sand. The leaks
edge basis. Delta populations can based partners able to work to- the construction of a tram tunnel in The Hague that funnel in the chemical and biological products of the
help each other by formulating gether in a coordinated way to prompted Dutch research into the repair and preven- bacteria, ensuring that they accumulate around the
tion of leaks in underground water-retaining structures source and slowly but surely plug it.” The first real-
like sheetpile walls. Deltares researcher John Lambert life application followed soon after, when a leak in an >>>
18 Deltares VIEWS Nº 2 Deltares VIEWS Nº 2 19
