deltares views nr 1 2009

Deltares VIEWS Nº 1 1

Solutions for a sustainable planet

Joint Industry Projects: shared problem, shared benefits

Modelling for megacities

magazine No. 1 2009

South-East Asia

South-East Asian Peatlands: how to halt degradation and start restoration

Page 14 >


Page 4 >

PhDs 7 >

Joint Industry Projects: shared problems, shared benefits

Page 12 >

NEWS Page 25 >

Modelling for megacities

Page 20 >

South-East Asia

The Netherlands

Calculated failure of a Smart Dike

Page 10 >

Delft-FEWS: flood forecasting around the world

Page 6 >

China

In China: capacity building for groundwater management

Page 17 >

CONTENTS

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DELTARES USA INC. established

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Deltares VIEWS Nº 14

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In 2008, four renowned Dutch orga-nisations decided to pool their knowledge and expertise. WL | Delft Hydraulics, GeoDelft, TNO’s Subsurface and Groundwater unit and parts of Rijkswaterstaat (the Dutch Directorate-General for Public Works and Water Management) joined to-gether to set up Deltares, an independent institute for the development, dissemination and application of knowledge concerning water, soil and subsurface. The result is an organisation superbly well-equipped to address complex, integrated issues relating to water, soil, subsurface management and spatial planning in deltas, coastal areas and river basins.

This magazine offers a literal and figurative overview of the world of Deltares. It is an anthology of ideas, in-sights, future prospects and alternative angles – in other words: news and views. It looks at research, support and advice on improving the management and design of delta areas, at exchanges of state-of-the-art scientific know-ledge and smart technology, and at fruitful exam-ples of cooperation with stakeholders at international, national and local level.

This first issue offers a wide range of topics. You can read, for example, about tailored support for urban water management, science-based advice on climate-friendlier methods of peatland management, the appli-cation of sensor technology in a ‘Smart Dike’, or a unique flood warning system with a rapidly growing user com-munity. The common denominator in all this? Unity in diversity. In other words: Deltares.

Harry Baayen, Managing Director Deltares

“How can life

be made safer,

healthier

and more

profitable?”

The literal meaning of the

name ‘Netherlands’ is ‘low lands’.

This country has developed on

the flat, low-lying land where

three major European rivers –

the Rhine, the Meuse and the

Scheldt – fan out to form a single

river delta beside the North Sea.

top: Managing

Director Harry Baayen

between Erik Janse,

Director Operations

and Market (left),

and Huib de Vriend,

Director Science

bottom:

The management

team on a field trip

The Netherlands is a very modestly sized but densely populated country and economically highly active. Thanks to its location, it is naturally well-connected to the rest of the world and its inhabitants have always engaged in an on-going battle to balance those benefits against the intrinsic risks of life in a low-lying river basin.

Living in such a place is a constant challenge. How can life be made safer, healthier and more profitable? These are questions faced by delta and coastal areas world-wide. For centuries, the Netherlands has acted as a test bed for innovations in spatial planning and water man-agement. The country has always been keen to share the resulting knowledge and know-how, just as it has always been eager to learn from other people’s experi-ence. One of the most important lessons is the need to take an integrated view of land and water, nature and man, risks and potential benefits. Only an integrated approach can provide sustainable solutions to issues re-lating to water, soil and subsurface. In the Netherlands, we have a name for it: we call it Delta Technology.

5Deltares VIEWS Nº 1

PREFACE


Delft-FEWS © M

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Flooding by

the river Meuse,

the Netherlands


Water management authorities worldwide are increa-singly turning to automated systems to help them manage flood risks. Masses of data, both meteorologi-cal and hydraulic, are being combined and processed to produce real-time information and forecasts that pro-vide a sound basis for flood warnings and rapid strate-gic decision-making.“The need is the same everywhere – to give maximum warning of flood risks – but the procedures, the form of automation and the software vary from one water man-agement authority to another. Delft-FEWS is making it possible for authorities worldwide to construct and use modern, tailor-made forecasting systems and to en-hance them by sharing new applications with other us-ers, despite the differences between their systems. We are supporting the process by way of advice, research, education and training.” So says Karel Heynert, manag-er of the hydrodynamics and operational systems sec-tion at Deltares. Together with Simone van Schijndel, manager of the operational water management section, he is responsible for the management and development of Delft-FEWS.

Flood forecasting around the world

Swiss FEWS system: work in progress

Stephan Vogt of the Swiss Federal Office for the Environment (Bundesamt für Umwelt, BAFU): “The development of the FEWS system for the river Rhine was co-initiated by us together with the Dutch Rijkswaterstaat in the late nineties. So Switzerland, where the Rhine rises, has been familiar with FEWS for quite a long time. One of the worst flood events that Switzerland has seen in the last century occurred in 2005. Damage amounted to some 3 billion Swiss francs. FEWS was used at that time and provided valuable information, even though it was then only in a pre-operational state. The 2005 flood event triggered a new approach to integrated risk management, taking into

account the possibilities of flood forecasting as a basis for early intervention. Consequently, we are now developing the FEWS system. In 2006 a manually driven stand-alone forecasting system came into operation. We are now looking to incorporate additional meteorological model data and will change the system to an automated one in order to provide real-time forecasts. This will give us more time for model interpretation. Over the next few years, this will be applied to additional river basins, not just the Rhine. One of the main strengths of FEWS and Deltares, is that it is relatively easy to build up a system step by step to suit one’s particular needs and criteria.”

>>>

What do water managers in the United Kingdom, Spain, Pakistan,

the Netherlands and the United States have in common? They all use

Deltares’ Flood Early Warning System (FEWS) to generate flood

predictions. The user community is growing, as is the number of

potential uses. So what is the secret of Delft-FEWS?


‘Building blocks’Delft-FEWS is a modular software package. Water management authorities use the different ‘building blocks’ to create their own forecasting systems. The soft-ware supports practically all the usual kinds of data, as well as various forms of data management and modelling. “You can build on and expand the application as much as you like”, Heynert explains, “keeping it dead simple or making it highly complex. Delft-FEWS always offers flexibility no matter how you use it, whether on an individual PC or as the backbone of a national flood warning system handling vast flows of assorted data.” For Deltares, however, Delft-FEWS is not an end in itself. “The point is to help water managers find answers to pressing questions”, says Van Schijndel. “What are the risks of flooding? How can flooding be predicted and how refined does forecasting need to be? Is research needed to achieve this? Is current monitoring data sufficient? What modelling information is relevant? Who’s going to use the forecasts? Delft-FEWS is a way of providing wa-ter managers with appropriate answers.”

Free of charge Delft-FEWS is available free of charge. “How many bodies around the world are concerned with flood forecasting?” wonders Heynert. “A couple of thou-sand, I should think, and not all of those are in a position to invest in advanced systems. We need to work together to succeed.” Users need not pay for the software. It is better for them to invest in their own operating environment (hardware, capacity, data files) and the development of necessary applications, like a plug-in for an external database or a visu- alisation facility to support policy- making. Then the user community can benefit from the applications developed by other users. As Van Schijndel explains, “FEWS is an open system that’s developing all the time. It’s now also being used to generate information about water shortages, water quality, oil spills and algal blooms. Other potential uses are to forecast hurricanes and

monitor the strength of dikes. The larger the user com-munity, the more can be achieved. Users stand to learn a lot from each other. That’s the lesson of each of our annual user days.”

Added value The United States’ National Weather Service is a brand new user. The NWS wants to replace its obsolete fore-casting system with Delft-FEWS and a number of new applications. “Of course, we’re delighted”, says Heynert. “The extent of the activities and the large-scale use will undoubtedly produce added value for the whole user community.” According to Van Schijndel, the flexi-bility in the scale of the application offers interesting prospects.”Some ‘clients’ want to use Delft-FEWS on a national scale, like the United Kingdom or now the US service, but of course the software can also be used at individual river basin level. Here in Europe, for instance, it’s being used for the whole Rhine basin. And in South-East Asia, the four-nation Mekong River Commission is using it for that river basin. Delft-FEWS and cross-border cooperation go well together.”

For more information: [email protected] or [email protected]

“You can build on and expand the application

as much as you like”

>>>

FEWS put to the test in Scotland

With a number of large rivers flowing through urbanised areas, Scotland has had its share of river flooding problems. About 100,000 properties across Scotland are at risk of fluvial or coastal flooding. The Scottish Environmental Protection Agency (SEPA) is the national flood warning authority. Michael Cranston explains how in 2006 SEPA decided to implement Delft-FEWS in order to provide a national flood warning system.“Several flood warning schemes have been developed over the last twenty years for major urban areas like Edinburgh. In 2005 we started looking for ways of producing more accurate and timely forecasts so we can give out targeted warnings. We needed a system with which to process and integrate all our hydromatic data, with links to flood forecasting models and a good user interface for flood duty officers. After running a pilot, we decided to apply Delft-FEWS to the flood warning schemes we

had for the south-west. We knew it would be relatively easy to roll out the system across the entire country, which we did. Now, all of our eight hydrological offices are using Delft-FEWS. Apart from various hydrological data, the system is now fed with data from the Met Office, the Storm Tide Forecasting Service and the Continental Shelf Model. And we are in discussion with energy providers about the input data from their hydroenergy schemes. All in all, we have come a long way in developing an operational system in a relatively short time. It was actually tested recently when we experienced a flood in Kilmarnock, in western Scotland. The forecasts and the feeds we got from our duty officers and our partners worked extremely well. We were able to issue warnings four to five hours before flooding occurred in Kilmarnock. This proved our flood risk management has substantially improved.”

9

Deltares USA Inc. was established on 1 November 2008 and has immedi-ately started work on a major project. The new company will work together with the US National Weather Service to develop the new forecasting sys-tem. Deltares has plenty of experi-ence in this field. The system will be based on Deltares’ own Flood Early

Warning System (Delft-FEWS) software, which is already in use in a number of countries, including the United Kingdom. Deltares developed and implemented a UK na-tional flood warning system in 2002 and is still closely involved in its management. The job in the United States


“Delft-FEWS and cross-border

cooperation go well together”

will likewise include the development and maintenance of the system, so it is important that Deltares should have a local presence.

Toon Segeren is very content with the contract: “The US system is going to be used differently from the one in the UK. The US has water systems of a different kind, with different characteristics and on a much larger scale, so the job will give us interesting new insights. Also, the National Weather Service is part of the Nation-al Oceanic and Atmospheric Administration or NOAA. Like Deltares, that’s a research-oriented organisation and we are very pleased indeed to have this opportunity to work with it.”

For more information: [email protected]

DELTARES USA INC. established

USA

Flooding by

the river Meuse,

the Netherlands

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Calculated failure

September 2008. Somewhere in the Netherlands, a hundred-metre-long

dike (levee) collapses, making international news. A flood disaster?

Fortunately not: ‘just’ an experiment. The Smart Dike is a unique facility

for testing dike monitoring systems. It is used to try out new inspection

and monitoring techniques and to gather useful information on failure

mechanisms. Like the instability investigated last September.

Deltares is one of the bodies behind that exercise and project manager

André Koelewijn talks about a successful trial.

of a Smart Dike

The NetherlandsMembers of the

Smart Dike Team


“It wasn’t just the dike that failed; the ground under it first gave way. The six-metre-high flood defence was toppled by major stability problems, exactly as intend-ed. A wide range of advanced monitoring equipment in and around the dike was tested and we got a detailed picture of the failure mechanism concerned: instability.” The Smart Dike project involves cooperation between sensor and information technology developers and suppliers on the one hand and research institutes and water management authorities on the other. Deltares is coordinating it. “We facilitate cooperation between the various parties and schedule the activities. The unusual thing is that the project also involves ICT research. The relevant sensors and the monitoring apparatus linked to them are field-tested under uniquely realistic conditions.”

Right inside Organising this sort of field test is a complicated busi-ness, if only because of the number of participants in-volved. In this case, ten different suppliers from a range of countries were testing their monitoring equipment, and bodies like TNO were conducting research. In addi-tion, Deltares was using conventional equipment to take reference measurements to calibrate the instruments being tested. Koelewijn: “From earlier trials and mod-els, we know the best place to take measurements in a collapsing dike is right inside it, because that’s where it begins to fail. At the same time, you have to watch for interference between the different monitoring in-struments. For instance, the audio source for a listening tube produces vibrations which can interfere with other instruments. To prevent that, you have to make com-promises. Deltares advises on the best place to install the sensors.”

One layer at a timeConstructing the dike was no easy task. If it collapsed too quickly, there would be no significant monitoring data. But it had to be weak enough for the failure to involve the ground beneath it. “For safety’s sake, we conducted an initial field trial on a smaller scale”, says Koelewijn, “The results of that mini-trial provided a model for the con-struction of the main test dike. The dike was construc-ted one layer at a time. The monitoring instruments are expensive and it was important not to damage them in the construction process. The contractor had the right experience of dealing with sensitive apparatus: working for the army’s Explosives Ordnance Disposal Command. The stability trial was a great success. The Deltares test data are currently being analysed prior to publication. To our mind, there’s no such thing as a ‘poor’ result. All information is valuable because it tells us more about the behaviour of dikes.”

InternationalThe Smart Dike is an international affair, as Koelewijn stresses: “Tried-and-tested technology doesn’t just come from the Netherlands and knowledge developed

here benefits everyone. Like the knowledge about dike erosion produced by French research.” Due to expertise gained from the Smart Dike project, the Netherlands has been invited to join a cooperative association of dam owners mainly in Canada and the United States. “Organisations in India and Bangladesh are also showing an interest in using sensors tested in the Smart Dike to monitor their dikes.”

Next trial So what’s next? “The next trial is scheduled for the autumn of 2009. The mechanism under investigation will be ‘piping’. This is where a dike failure is caused by sand boils. In other words, water washing away part of a sand layer from underneath the dike. There are also plans to test a particular method of strengthening exis-ting dikes.” First of all, however, a new Smart Dike must be built. “But not in the same place. The ground under-neath a dike collapse is weakened for decades to come.”


Proved in practice

Inventec was one of the participants in the macro-instability trial. Director Martin Veldhuis: “We tested our D!kealert system, which uses optical glass fibres. You embed them at a shallow depth in the dike and launch a light pulse into them. The glass fibre expands and the back-scattered light is analysed by a reading unit; this tells you whether there’s any deformation in the dike, and if so where. A single reading unit can monitor a 25-kilometre stretch of dike and the system is extremely sensitive: deformations are registered right down to 0.002 mm/metre. So D!kealert is ideal for use as an Early Warning System. We knew that from feasibility studies, but now we’ve proved it”. If measurements show that the dike is starting to move, the owner can proceed to close monitoring of the area concerned. There too, Inventec has a solution: the company acts as an agent for ShapeAccelArray/Field (SAAF), produced by the Canadian company Measurand Inc. Veldhuis: SAAF is an inclinometer based on nanotechnology. A SAAF is an array of linked sensors which will hinge in all directions. So each element works, as it were, as an inclinometer. By taking readings from them all simultaneously, you can construct an accurate 3-dimensional image of the deformation.” The SAAF was used in the field trial preceding the instability trial. SAAFs are also used in the Smart Dike to take reference measurements. Reason for satisfaction? “Certainly, and we’re also very happy with the way Deltares cooperates with us and coordinates the trials.”

of a Smart Dike

Joint Industry Projects Shared problem, shared benefits

On sandy sea beds, like that of the North Sea, currents and wave action can produce scour. This happens, for example, around the jack-up platforms used to drill wells in new oil and gas fields. Excessive scour can lead to a reduction of foundation fixity at the seabed, with all the potential consequences. However, there are no guidelines available for scour assessment, scour predic-tion and scour protection design for jack-up footing. In other words, how to deal with this problem is a pressing issue for users, owners and designers of jack-up plat-forms and one they would be glad to see answered.

Looking for the solution to a specific problem

requiring fundamental or applied research?

Joint Industry Projects (JIPs) are a way of creating

exclusive knowledge in partnership.

12 Deltares VIEWS Nº 1

Scour management“As a consultancy assisting individual parties, Deltares has carried out various scour assessments in the past”, explains senior researcher and advisor hydraulic engi-neering Daniel Rudolph. “In doing so, we discovered the lack of detailed knowledge concerning the behaviour of jack-up platforms in an environment liable to ero-sion.” Following physical modelling, Deltares developed a dataset of scour measurements for a number of dif-ferent types of jack-up footing, leading to an improved method of prediction. “In view of our extensive research and modelling facilities and our experience of developing highly specific software applications, we now have a real possibility of making a valuable contribution to scour management by way of applied research.”

research. Wave specialist Martijn de Jong: “Numerical and physical modelling of wave conditions and resulting vessel motions in shallow water led to the development of specific knowl-edge and tools which can be used to increase the reliability of offshore LNG terminals. It was the combined efforts of coastal engineers, vessel hydrodynamics specialists, and de-signers that made this project such a success. Over twentyfive companies and research institutes recognised the relevance of this research sub-ject and participated in the project.”

High wavesComFLOW-2 was another successful international JIP. It involved coope-ration between MARIN, Deltares, the University of Groningen, Delft University of Technology, FORCE Technology and around twenty parties in the off-shore industry. The main purpose was to improve Com-FLOW, a computer model used to calculate wave forces on ships and offshore structures like jack-up platforms and semi-submersibles. Since storm waves can be high enough (over 10 metres is no exception) to cause ex-tensive material damage and endanger human life, it is extremely important to the offshore industry to under-stand complex wave movements. ComFLOW-2 is there-fore unlikely to be the end of the story: ComFLOW-3 is on the horizon.

Good deal Rudolph feels that in cases like this a JIP is the best way there is of filling the knowledge gap. “We stumble on a problem and realise that there’s a lack of fundamental knowledge about it. We don’t have any structural solution - after all, it takes complex research to find one, and that takes time and money. So if we can agree to share the costs of research with a number of partners – with a fixed agreement that only they will have access to the results – everybody wins. A problem shared is a problem halved – or, in the case of a JIP, decimated.”

For more information: [email protected], [email protected] [email protected]

“We stumble on a problem and realise that there’s a lack of fundamental knowledge about it”


OSCARRudolph sought cooperation with companies that may be interested in the knowledge resulting from such re-search. “The oil and gas industry, companies hiring out jack-ups and designers… They all stand to benefit from the answers to our key research question: under what conditions will scour occur and to what extent?”

The JIP Offshore Scour Assessment and Remedial Measures (OSCAR) project was launched in October 2008. “It’s a multi-faceted project. By 2010 it should have produced a systematic database of scour measure-ments for various types of jack-up design, including information on the effectiveness of remedial measures, guidelines for scour-friendly jack-up design, prediction tools for scour depths around and below spud cans, and a scour management tool (OSCAR - the scour manager) that can assist in scour prediction and the conceptual design of remedial measures.”

Other JIPsJIPs vary widely in scale and approach. For example, since 2003 Deltares has been running a Joint Industry Project the aim of which is to mitigate the effects of gas pockets in wastewater pressure mains. Such gas pock-ets can substantially reduce mains capacity – by 90% in some cases – increasing energy costs and causing unnecessary overflows. Indeed, the blockage may be so great that it becomes impossible to operate the pres-sure mains at all. Rudolph’s colleague Ivo Pothof: “This project, CAPWAT, is being conducted in collaboration with various partners in the Netherlands, such as en-gineering consultants, pump manufacturers and water boards.”

The feasibility of using osmotic membranes to generate electricity (Pressure Retarded Osmosis, PRO) is the sub-ject of a new JIP currently in its start-up phase. Fresh water flows through an osmotic membrane to the pres-surised brackish water side and powers a turbine and generator. The partners in this JIP will include energy companies, membrane producers and pump manufac-turers. A pilot plant is to be built in order to investigate the performance and efficiency of complete membrane modules.

HAWAIDeltares has also been involved in a successful interna-tional JIP called HAWAI (sHAllow WAter Initiative), which was launched in partnership with the Maritime Research Institute Netherlands (MARIN) in 2005 and completed late 2008. The purpose of this JIP was to develop predic-tion methods for wave conditions in shallow water and resulting vessel motions of LNG carriers at near-shore terminals. When LNG carriers (ships used to transport Liquefied Natural Gas) are moored in shallow water, low frequency waves may cause excessive vessel motion. This is a specific but complex problem requiring targeted

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top: Attendees

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modelling facility


South-East Asian PeatlandsHow to halt degradation and start restoration

Deltares supports

planning and design

of peatland water

management

systems, aiming to

control water levels in

order to reduce

subsidence and

carbon emissions,

and conserve forests.

South-East Asia


Peatlands are extremely wet (90% water). The dry com-ponent consists of vegetal remains. This is mainly car-bon and highly sensitive to hydrological changes. In many areas, deforestation, drainage and the burning of peatland have resulted in substantial C02 emissions, loss of biodiversity, soil subsidence and reduced capacity for water storage. This has increased the risk of flood-ing in low-lying areas inside them and downstream. In order to halt and reverse these and other effects, there is an urgent need for science-based insights into more sustainable peatland management.

UnderstandingNow that the severe consequences of large-scale peat-land degradation are being recognised worldwide, more and more governments, NGOs and companies are eager to invest in measures to counter further degradation and improve conditions. The question is what measures will be most effective in the long term.Dr Aljosja Hooijer, senior advisor at Deltares, and other Deltares consultants are involved in various restoration advisory projects and research initiatives. “Forested lowland peatlands make up 10% of the South-East Asian land area (some 27 million hectares). More than half of this is now fully deforested and often drained, and much of that developed land is unproductive. There has been relatively little study of tropical peatlands and their water management requirements are poorly understood. That is why, in addition to what we learn through advisory projects, Deltares is investing in and conducting funda-mental research into the causes and effects of peatland degradation.”

“We are talking about millions of hectares of forest ve-getation remains that have accumulated in these peat-lands over thousands of years but could largely be lost within a few decades.” The volume and characteristics of peat layers vary considerably. In many places, the peat is more than 10 metres deep but in others less than three; in some areas the vegetal remains are almost fresh, in other areas they are largely decomposed. “In other words, we require more specific knowledge of what we are dealing with locally. How do different peat types respond to different drainage regimes? Exactly what processes contribute to the oxidation and shrinkage of the peat and to what extent? How does drainage affect

water tables?” Conservation and development need to be balanced, says Hooijer, and require careful planning that includes science-based water management. “Peat, after all, consists mostly of water. Improved water man-agement will benefit production in developed peatland areas and mitigate the effects of droughts, floods and subsidence.”

AssessmentTo acquire much-needed knowledge, Deltares has launched various initiatives. In 2006 the PEAT-CO2 report was produced in collaboration with Wetlands International and Alterra. It is an overall assessment of CO2 emissions from drained peatlands in South-East Asia. >>>

Kalimantan

One of the larger projects in the area involves a programme for the Rehabilitation and Revitalisation of the Ex-Mega Rice Project (EMRP). Hooijer: “Of the total South-East Asian peatland area, 80% is in Indonesia (22.5 million hectares). The Dutch and Indonesian governments joined forces in 2007 to develop a Master Plan for an area in the river delta of Central Kalimantan where the Indonesian government originally intended to convert up to one million hectares to rice cultivation. Hence the name Mega Rice Project. The peat soils failed to support rice growth, however, and extensive drainage, deforestation and wildfires have turned most of the area into unproductive wasteland.”Assessments show that the hydrological function of the peatland has been permanently changed and flooding is now a serious problem. “Most of the 920,000 hectares of peatland in the area, half of which is over three metres deep, is now a significant source of CO2 emissions. Action is required.” The Master Plan was completed in October this year by a Dutch consortium led jointly by Euroconsult Mott MacDonald and Deltares. It will be implemented over the next few years with support from the relevant Indonesian ministries, and with funding from the Dutch and Australian governments and other sources.

Tropical peat is vulnerable. Over the past two decades, peatland

development in South-East Asia has led to rapid degradation of vast

stretches of peatland. This has had a substantial impact on the

global climate as well as on the local environment. Time for action,

but of what kind?


Kampar Peninsula

Another project is being run on the Kampar Peninsula, in the Province of Riau, Sumatra. Deltares has been called in by a pulp and paper producer to support improvements in water management in 100,000 hectares of acacia plantations on peatland. The aim is to reduce soil subsidence (leading to flooding), C02 emissions and degradation of adjoining conservation forest. “In the Kampar Science-Based Management Support Project (SBMS Project), we are heading a team of consultants and scientists, including staff from the University of Leicester, ProForest, University of Helsinki, University of Wageningen and the producer itself. The project started in April 2007 and will take three years.” Activities include the monitoring and assessment of relationships between water depth and peat subsidence, CO2 emissions and forest health. Results will be applied to long-term water management strategies for the plantations and adjoining conservation areas, and will be used in the design and implementation of water management infrastructure. “Basically we are looking for sustainable ways to maintain production in the plantations while conserving the surrounding peat swamp forest. The company is trialling several water management dam-and-bypass systems in different pilot areas, and we are monitoring the impacts and studying the underlying hydrological and soil processes. Hundreds of dams have already been built in the plantations and water levels have been raised substantially. More will follow.”

“By combining data on the extent and depth of peat, present and projected land use and water management practices, decomposition rates and peat fire emissions, we were able to project present and future emissions”, says Hooijer. “We were thus able to demonstrate clearly the significance of emissions resulting from decomposi-tion of drained peatlands and from peatland fires asso-ciated with drainage and degradation. Total emissions from these sources may be equivalent to as much as 7% of global fossil fuel emissions, and we expect these will now gradually be recognised by intergovernmental bod-ies like the International Panel on Climate Change.” The assessment also shows that emissions from peatland drainage may further increase over the coming decades if peatland management and planning practices are not changed, and that they will continue throughout the 21st century.

>>> As part of the Singapore Delft Water Alliance (SDWA) programme, the University of Singapore and Deltares have launched the four-year Peatland Water, Carbon and Ecosystems Management Research Programme to improve peatland management practices in South-East Asia. The programme comprises five work packages, and includes the development of training programmes for specific target groups. “Together with the Singapore National Environment Agency, we are undertaking a peatland water management training programme in the Indonesian Province of Jambi, which also serves as a study site. This will be done in collaboration with the University of Jambi. Needless to say, collaboration with relevant organisations in Indonesia is highly important if we are to raise awareness and understanding of the requirements for sustainable peatland management.”

For more information, visit http://peat-co2.deltares.nl, http://www.sdwa.nus.edu.sg/projects.htm or [email protected]


Sixty per cent of the world’s drinking and irrigation wa-ter is groundwater. It is vital, therefore, that adequate groundwater sources remain available and that they should not become contaminated. Reliable information is essential if we are to be able to manage these valuable resources effectively and take prompt action to protect them where necessary. Over the last five years, Deltares has been helping government authorities in China develop a Groundwater Information Centre.

In view of its vast economic growth in recent decades and the prospect of large-scale climate changes, project manager Dick van Doorn thinks that China has taken the right steps at the right time to ensure effective man-agement of its groundwater resources. “We completed the project this year and it’s been very successful. Both sides have learned a great deal. China is prepared to invest a lot of energy and resources in the solution of its groundwater problems.”

The many project activities included the delivery of training to over a hundred Chinese experts (partly in China and partly in the Netherlands), the establishment of three local databases and a central database at CIGEM (the China Institute of Geo-Environmental Monitoring), and the development of groundwater models that have helped China to draw up policy scenarios for the future. >>>

Capacity building for groundwater management

In China


Tiger Spring area

in JinanChina

Most Chinese cities are heavily dependent on groundwater for their urban water supplies. In the North China Plain, the figure is 70% dependency. Of all groundwater abstracted, 80% is used for irrigation. Especially in North China, more than 50% of the total water supply comes from groundwater.


Background The project was launched in 2003 and the training of Chinese experts at Deltares and the UNESCO-IHE In-stitute for Water Education began that year. However, it took extensive negotiations between China and the Netherlands to get that far. The first talks took place as long ago as the 1980s. In 2001 the Dutch Ministry of Foreign Affairs (DGIS) decided to provide funding for the project (around € 3 million) under its Development and Environment Related Export Transactions (ORET/MILIEV) Programme. Once the Chinese Ministry of Finance (MOF) had given its approval, the agreement was signed in Bei-jing in October 2002. China’s contribution to the project consisted of many hundreds of man-months and local hardware.

Information needsThe ultimate aim of the project was to contribute to the long-term socio-economic development of China by ensuring the sustainable use of groundwater resources. Sustainable groundwater resources development plans cannot be formulated without adequate information on groundwater quantity and quality. Producing such information requires optimised groundwater monitoring networks and well-calibrated groundwater simulation models to predict the impacts of groundwater develop-ment scenarios. A national Groundwater Information Centre was found to be necessary to meet China’s infor-mation needs in this respect. The centre is to be respon-sible for groundwater monitoring, information dissemi-nation and the formulation of sustainable groundwater resources development scenarios.

WellsThe key aim is to obtain reliable data on which to base a proper system of groundwater management. To achieve this, wells had to be sunk and sensors installed in them to monitor all the necessary quantity and quality pa-rameters. To optimise these groundwater monitoring networks, automatic data loggers were installed for efficient groundwater management and data collec-tion. The wells had to be sited in such a way as to give the management authority a clear picture of the sta-tus of the groundwater throughout its area. The REGIS (REgional Geohydrological Information System) data-base developed in the Netherlands proved, after some modification, to be suitable for use in groundwater management in China. Van Doorn: “It would be physi-cally impossible to investigate the status of ground-water throughout the whole of China, so we conducted pilot studies in three areas. They were selected because of the major diffe-rences in their problems and subsoils: the Beijing Plain, the Urumqi River Basin and the Jinan Karstic Spring Catchment area.”

Satisfaction Van Doorn looks back on the project period with satisfac-tion. “I’ve been visiting China for years now and I’ve seen

“Without good quality

groundwater, serious

damage is inevitable”

>>>

Project profile

Name: Capacity Building of a China Groundwater Information CentreDates: 24 March 2003 – 31 October 2008 Counterparts: Deltares, UNESCO-IHE, Van Essen Instruments Partners: China Institute for Geo- Environmental Monitoring (China Geological Survey), Geo- Environmental Monitoring Stations of Xinjiang, Beijing and Shandong ProvincesFunding agencies: Dutch Ministry of Foreign Affairs/ DGIS (ORET/MILIEV), Ministry of Land Resources of ChinaType: Institutional Capacity Building

top: Camels in

Chaiwopu basin,

south of Urumqi

bottom: Cotton

pickers in irrigated

area, north of Urumqi


the country change out of all recognition. For a European, it’s almost unimaginable that a country’s economy and technology can advance so quickly. Without good qual-ity groundwater, serious damage is inevitable. Our proj-ect has proved to be particularly useful in averting that. Altogether, we dealt with an area where between forty and sixty million people live and work.” All the parties involved would like to extend the project to similar arid areas in northern China but the feasibility of any sequel depends on political and budgetary decisions in China and the Netherlands.


400 0 400 kilometers

Three pilots area

Three pilots

Urumqi riverbasin pilot

Jinan karstic springcatchment pilot

Beijing plain pilot

Beijing Plain

Groundwater resources in the Beijing Plain area have been rapidly depleted by over-exploitation, constant drought from 1999 to 2007, and reduced recharge from rivers. In the Chaobai River Catchment Area, groundwater levels declined by more than 20 m between 1999 and 2005. A modelling study of the Beijing Plain indicated that the main recharge of groundwater is by direct infiltration of pre-cipitation, followed by boundary inflow and river leakage. However, drought has caused a continuous decline in inflow and leakage. The cross-basin water transfer

project (South to North water transfer) will be operational from 2009 and by 2010 a total of 1 billion m3 of water will in principle be transferred to Beijing each year for use in urban and industrial water supplies. Groundwater abstraction willthen be reduced. The simulation model was used to determine how a steady-state groundwater system can be achieved.

Other project activities took place in the Urumqi River Basin and the Jinan Karst Spring Catchment Area. Read more about the subject at www.deltares.nl

Chinese and Dutch

experts around

a monitoring well

Modelling formegacities

20 Deltares VIEWS Nº 1

Deltares assists urban water managers with integrated analyses, predictions and advice

South-East Asia


In the night of 3 – 4 June 2008, water from the Java Sea surged into Jakarta. It wasn’t a flood disaster, however. Deltares had predicted the exceptionally high tide and the authorities had taken preventive measures. Jakarta breathed a sigh of relief – but not for long. Like so many urban areas in similar circumstances, the city is strug-gling to cope with a host of water management prob-lems. By considering these in an integrated way and finding structural solutions, Deltares is working to cre-ate a safe, healthy and sustainable urban environment. And not just for the people of Jakarta.

You might say that Indonesia’s capital Jakarta in the delta of the Ciliwung River is between the devil and the deep blue sea. Groundwater extraction is causing the ground under the city to subside by about 8 cm a year. The area’s meagre sea defences are also subsiding, mak-ing flooding a real threat, especially since almost half of this vast city (population over 9 million) lies under sea level. But the main problem is the limited capacity of the storm drainage system. In the rainy season, this causes major problems, with downpours often flooding whole areas of the city. Add to this the expected consequences of climate change and it is clear that something really has to be done.

Flood InitiativeAs part of the Jakarta Floods Initiative (JFI), a public-private partnership project launched by the Netherlands in 2007, Deltares has mapped all the watercourses in an area measuring 60 km by 40 km. JanJaap Brinkman, who is responsible for the Flood Hazard Mapping part of the JFI, explains: “The disastrous floods of February 2007 cost the lives of more than fifty people and caused almost a billion US dollars worth of damage. The episode roused great international interest in the flood problems of Jakarta. The Indonesian government has specifically asked for the Netherlands’ help in the battle to prevent flooding.”Deltares has used its know-how to improve understan-ding of the precise nature of the problems and the effectiveness of possible measures. “Thirteen rivers flow through Jakarta and the city also has an extensive canal system. This whole complex is now being modelled for the first time and the project is producing valuable in-formation.” It has shown, for example, that 70 to 80% of the February 2007 flooding could have been prevented by clearing the clogged waterways of sediments and domestic waste. “This information also provides the ba-sis for activities like flood hazard mapping. Where will structural problems occur, given a particular amount of rainfall? How does this relate to disaster management and evacuation plans?

Jakarta

>>>Bird-eye view of Hong

Kong City Center


Where are measures like dredging and river dikes most urgently needed? These questions can now be answered.” And not only that: the flood hazard maps are also valu-able in relation to town planning and as a tool for edu-cating and informing the population.

Prediction What about the sea? Brinkman thinks the high water level of last June has nothing to do with climate change. “By combining our coastal and urban models, we discovered that the current exceptionally high sea levels are the re-sult of a lunar cycle. Every 18.6 years, the moon’s orbit passes especially close to the earth.” Deltares is keeping a sharp eye on flood risks in Jakarta. “We now produce daily water level predictions for Jakarta. However, we are only just starting to make structural improvements in urban water management and the creation of a safer coast.” As the moon’s orbital cycle takes it steadily fur-ther away from the earth again, sea levels will subside. But in 18.6 years, the city will face the same problem again. By that time, however, the city and its coastal defences will have subsided by almost another 150 cen-timetres. Without structural measures, says Brinkman, a four-kilometre coastal strip in which millions of people now live will be seriously threatened if not entirely un-inhabitable. “Jakarta can think itself lucky that Deltares has discovered this. The city now has 15 years to take

the necessary measures. And it will need all of that time, because large-scale engineering works will be required. The insights provided by our work mean that efforts can be focused where they are needed.”


The Hong Kong Special Administrative Region (SAR) of the People’s Republic of China covers an area of over a thousand square kilometres. Its collection of islands and peninsulas means that almost all of Hong Kong is surrounded by water. An exception is the North Dis-trict, which is separated from the Chinese mainland by a natural border: the Shenzhen River, which flows into the Pearl River delta. Hong Kong is hilly but, like Jakarta, its urban area suffers from periodic flooding following heavy downpours. A master plan for dealing with this risk in the two northern districts of the New Territories is being drawn up with Deltares’ assistance.

Downpour“We began examining the drainage of this area in 2008”, says Adri Verwey, senior specialist in modelling systems. “Around half of the area consists of steep hills covered with low vegetation. During the summer rainy season, there are frequent downpours. As much as 145 mm of rain can fall in an hour. The water rushes downhill into what are now heavily populated areas. The urban area is set to expand and there’s a big risk of flooding, even though measures like the construction of concrete lined drainage channels have already been taken. There’s a good reason for the warning you see posted up every-where beside these channels. The response time is very short.”

Exact knowledgeConsultant Mott MacDonald and Deltares have been asked to draw up a master plan for this area investigating the present drainage system and proposing measures to improve it. Although flood prevention measures have already been taken in recent years, Verwey thinks there is every reason to develop a better understanding of the system in order to be able to anticipate future develop-ments. After all, urban expansion will put further pressure on the drainage system. “The problem is not just urban expansion in Hong Kong. Just over on the Chinese side of the river is the city of Shenzhen. These days, it has a population of ten million, whereas thirty years ago it was just a village. Silt from the Pearl River is another is-sue. During the dry season, it’s deposited in the mouth of the Shenzhen River. Both Shenzhen and part of the Hong Kong North District rely on the river to discharge their drainage water. And plans to develop new residen-

Hongkong

>>>

above: In the night

of 3 - 4 June 2008,

water from the

Java Sea surged

into Jakarta


ter quality, both during the present transitional phase and thereafter. Saltwater flora and fauna will perish. The water from the rivers and canals emptying into the bay inevitably contains pollutants. Without tidal movement to flush the bay, oxygen depletion, unpleasant odours and bacterial pollution may result. Excessive concentra-tions of nutrients may also produce undesirable algal blooms. In view of Marina Bay’s planned function as a combined freshwater reservoir and high-end leisure and lifestyle area, the question is how to manage the water to get the best results.

High qualityThe Singapore Public Utilities Board (PUB) – managing authority for the entire drinking water and wastewater chain – has asked Deltares to assess the impact of the transition on water quality and to guide developments in water quality management. “Water management in Singapore is a whole other story”, confirms Tjitte Nauta, project manager Marine and Coastal Systems. Singa-pore’s hydrological situation and the high water quality targets for the area call for an unprecedented form of water quality control. “Marina Bay is booming. In this downtown district, a high-profile business area and en-tertainment quarter, the quality of life is extremely high. The same standards are being set for the reservoir. The water must be clear, clean and unpolluted. But, however good the technology, you can never completely safe-guard a body of water like the Marina Bay Reservoir. No sewer is entirely leak-free and it’s impossible to identify and eliminate every source of pollution. All you can do is identify the possible risks and do your utmost to control them. That, in a nutshell, is what we’re doing right now. The result of our efforts will be an Operational Manage-ment System (OMS) that will enable the PUB to manage the reservoir with maximum effectiveness and forestall risks by combining non-stop monitoring of water qual-ity and quantity with water quality forecasts.”

tial and industrial areas make it impossible to increase the discharge capacity of certain drainage channels. So it’s an extremely complex problem.”

CyclonesDeltares will assist in the preparation of the master plan by surveying the current situation and estimating sce-narios. What will happen if urban expansion continues? What will be the effects of climate change? “We are even producing an estimate of the possible frequency of cy-clones.” To achieve all this, the modelling of the area is being improved. “Buildings, morphology, sedimen-tation, earlier flood episodes, physical obstacles and changes in the drainage system, sewerage… everything is being taken into account in order to produce an over-all, up-to-the-minute picture of the situation. Alterna-tives emerging from the scenario studies include not only an improved use of water detention, modification of discharge capacities and the creation of polders and diversions, but also environmental measures like man-aging mangrove forests and creating ‘green’ rivers. But let’s not get ahead of ourselves. The master plan isn’t due for completion until 2010. First of all, we need to make a thorough analysis of the situation.


Urban water management embraces many different disciplines, as illustrated in Singapore, where Deltares faces a different kind of challenge. With a population of over 4.5 million in an area of less than 700 km2, Singapore is a relatively small but densely populated country with a big demand for fresh water. In order to meet that demand in future without needing to import water from Malaysia, as happens now, the Singapore authorities are currently creating reservoirs for rain-water storage. One method is to close off estuaries, like Marina Bay in the heart of the city.The Marina Barrage, completed in 2008, was built to protect low-lying parts of the city against flooding. At times when the city is swept by torrential rain, the storm water drains away through nine sluices, supple-mented in case of flooding by seven pumps, each with a capacity of 40 m3/s. The Barrage will eventually turn Marina Bay into Singapore’s fifteenth freshwater reser-voir. With a catchment area of some 10,000 ha, it will be able to satisfy approximately ten per cent of the city’s current water demand.

FlushingBut first the conversion must be completed. Meanwhile, Marina Bay is the focus of rapid up-market urban de-velopment. The closure of the bay entails risks to wa-

Singapore

The Marina Barrage,

completed in 2008,

was built to protect

low-lying parts of the

city against flooding

>>>



SimulationTo manage the water in Marina Bay, it will be necessary to identify all the factors that can impact on it and to simulate all the water management processes. Deltares manages large-scale modelling systems for tidal move-ments in the South China Sea and the Straits of Singa-pore. Nauta: “We’ve used these to establish surrounding conditions for a detailed 3D model of Marina Bay. We have also linked this to a 1D model of the urban water systems connected to the reservoir.”No sooner said than done. Integrating the hydrology (HYMOS / SOBEK), hydrodynamics (Delft3D-FLOW) and water quality (Delft3D-WAQ / ECO) of the Marina Bay catchment area, has enabled Deltares to analyse the effects of proposed management measures now and in the future.

AdviceNauta thinks that further measures will be required be-fore mid 2009, the starting date for the full conversion of the reservoir to a freshwater system. Singapore will soon have an extensive infrastructure for the recircula-tion and purification of wastewater and storm water. The product can be used to constantly refresh the water in the reservoir. “We have estimated the potential for this and come to the conclusion that an optimum combina-tion of source control, including elimination of leakage from the sewage system, recirculation and aeration of water in the reservoir will significantly reduce the risk of breaches of water quality targets and make the problem more controllable.”

InnovationThe water quality modelling framework provides the ba-sis for an initial version of an operational system com-bining all the relevant data flows. In 2006 work began on an intensive monitoring programme. Sensors were placed and measurements taken all over Marina Bay. “We’ve now collected a great deal of information about water quality and quantity. For instance, by monitor-ing the nature and quantity of substances, we’ve estab-lished exactly how heavy rainfall flushes out the canals that empty into the bay.” Work is now being done on turning the Online Manage-ment System into a continuous water quality forecast-ing system. “That way, risks can be forestalled. It can even become a completely automated process.” Nauta is uncertain when all this will happen. “But by the end of the transitional phase in 2009, proper management of the new reservoir’s water quality will definitely be pos-sible.” That won’t be the end of the story. “Ideally, to optimize the management of the reservoir, the system will also need to cover all the linked reservoirs. The first moves in that direction have already been made and ex-tra research programmes have been established.” The PUB, the National University of Singapore and Deltares have set up a Centre of Excellence for Water Knowledge (the Singapore-Delft Water Alliance) to conduct such re-search. “Flood forecasting systems already exist, but an integrated management system for overall water qual-ity that can also be used for forecasting is something completely new.”


>>>

Pearl River Delta in the picture

In the Pearl River Delta, the Chinese province of Guangdong and Hong Kong SAR have been working since 2000 to create joint sustainable development and environmental protection policies. One main policy focus is water quality management. Water quality is threatened by the increasing quantities of domestic and industrial wastewater. To investi-gate the problem, use is now being made of state-of-the-art 1D-3D models developed by Deltares. In a separate interview, project leader Jos van Gils explains how Deltares has managed to model the entire river basin, a complex and sizeable water system, by linking separate model systems. Van Gils: “This means that predictions are based on the whole picture, with all the consequent benefits for water quality management. It may sound simple, but this is a unique project, in terms both of software development and the size of the area being modelled.”

Read the entire article on www.deltares.nl

Focus on water

quality management


Water Partnership have carried out a research project on the sustainable development of deltas. The research report provides background information on the main themes of Aquaterra 2009 as well as profiles of eight river deltas around the world.

For more information, visit www.aquaterraforum.com or contact [email protected]

IGRAC celebrates 5TH anniversaryThe International Groundwater Resources Assessment Centre (IGRAC) aims to improve the understanding and management of the earth’s freshwater resources through the sharing of information and experience. One way of achieving this is the development of a Global Ground-water Information System (GGIS). IGRAC operates under the auspices of UNESCO and the World Meteorological Organization. Founded in 2003, IGRAC is headquartered at Deltares in the Netherlands.

A global perspectiveOn 5 June 2008 IGRAC celebrated its fifth anniversary with a symposium on ‘Groundwater, a Global Perspec-tive’. The symposium was hosted by Peter Letitre, direc-

Sharing knowledge of sustainable soil management worldwide

The Netherlands Soil Partnership

Aquaterra 2009From Tuesday 10 to Thursday 12 February, Amsterdam RAI hosted Aquaterra 2009, World Forum on Delta and Coastal Development. Aquaterra serves as a platform for everyone involved with the management and de-velopment of delta and coastal areas around the world. The forum comprised an extensive programme which included an introduction to major themes as well as a presentation of best practices. A number of specific ‘Delta cases’ were discussed by international experts. Aquaterra also included an exhibition of key organi-sations involved in delta development. To support the Aquaterra conference, Deltares and the Netherlands

In a small, densely populated country like the Nether-lands, good soil management is an absolute necessity. The Netherlands has been developing and pursuing in-tegrated policies on soil management, spatial planning, agriculture, water and energy ever since the 1980s. As a result, a great deal of knowledge has been developed and is now available. Dutch government agencies, compa-nies and knowledge institutions are keen to contribute to the development of sustainable environmental poli-cies worldwide by sharing their experience of function-based soil management in combination with risk man-agement and land development. There is widespread international interest in areas such as Dutch techniques

NEWS

for the remediation of contaminated soils. Concepts for the subsoil storage of gases or water and for breaking down contaminants on site (without excavating the soil) are also attracting attention. The Netherlands Soil Part-nership (NSP) was set up on 15 July 2008 as a way of sharing knowledge effectively and learning from other people’s experience. This public-private partnership con-centrates and coordinates Dutch expertise and experi-ence regarding policies, knowledge and implementation in the area of sustainable integrated soil management. Deltares is one of the initiating bodies.

For more information: www.nsp-soil.nl

tor of IGRAC, and a group of internationally renowned groundwater specialists spoke on a range of subjects. The symposium also saw the premiere of a short film on Groundwater and Global Change. This is one of four films on groundwater that IGRAC has produced to raise awareness among non-specialist audiences. They can be seen on YouTube, or you can contact IGRAC through its website to obtain a copy on DVD. The lessons learnt from the past five years and from the symposium will be taken forward in IGRAC’s future activities, such as its participation in the next World Water Forum.

For more information on IGRAC and the symposium, including presentation downloads, visit www.igrac.net

The Netherlands


For more information:[email protected] andwww.eurogoos.com

New Dutch-Sino Centre for Coastal Geology

Deltares new EuroGOOS memberDeltares was one of the two new in-stitutes welcomed into the EuroGOOS community at the Annual Meeting in Galway on 9 October 2008. Nicki Villars of the Marine and Coastal Sys-tems Unit attended and represented Deltares at the official signing ceremony. Deltares and the Portuguese Instituto Hidrografico bring the total number of EuroGOOS members to 35, representing 17 European countries.

EuroGOOS is an Association of Agen-cies, founded in 1994, to further the goals of GOOS, the Global Ocean Observing System (GOOS). EuroGOOS is focused on the development of operational oceanography in the European sea areas and adjacent oceans, while GOOS is the overall international programme preparing the permanent global framework of observations, modelling and analysis

September 2008 saw the establish-ment of the Dutch-Sino Centre for Coastal Geology (DSCCG), a new institute set up as a platform for co-operation between Deltares and the China Geological Survey (CGS). Con-tacts between the two institutions go back more than 30 years and the launch of the DSCCG has not been a hasty business. The signing of the memorandum of understanding was preceded by a two-year project during which joint workshops were held to gain insight into each other’s knowledge in the field of coastal and marine research.

ChinaDr Zhong Ziran,

Director of the

China Geological

Survey, and Professor

Huib de Vriend,

Director Science

at Deltares, sign a

Memorandum of

Understanding on

the new institute

Signing

ceremony

of ocean variables needed to support operational ocean services where-ver they are undertaken around the world.

Within EuroGOOS, Deltares is now the fourth institute from the Nether- lands, together with KNMI, NWO, and Rijkswaterstaat-Waterdienst. Deltares is currently also chairing the NOOS community within Euro-GOOS, which focuses on the North-West European Shelf area. The in-stitutes of the NOOS community exchange daily water level forecasts as well as coastal monitoring infor-mation in support of national flood forecasting services. In the future, NOOS and EuroGOOS will also ex-tend their focus to include water quality and ecological forecasting, for example to predict (harmful) algal blooms in coastal waters.

The joint research programme for the next years will focus partly on the improvement of research methods, for example in the seismology field. Another focus will be on market- related issues, like the feasibility of creating artificial offshore islands. Joint research projects will tend to utilise advanced Chinese research vessels. Knowledge exchange will be further promoted by temporary ex-changes of personnel between the two institutions.

Fore more information: [email protected]

Europe

NEWS

Eco-hydrodynamic modelling of primary production in coastal waters and lakes using BLOOM

“Municipality does not want sedi-ment pits in Lake Loosdrecht” and “Beach near Texel covered by mas-sive foam layer”. These are two examples of headlines in which al-gae growth is a central issue. Over recent decades, there has been an increase in the discharge of nu-trients from sewage treatment

plants, agriculture and industry into aquatic ecosys-tems, causing effects which are considered objection-able. On the other hand, life on earth depends on the fixation of sunlight by plants as a source of energy and in this respect no other ecosystem, including the tropical rainforests, rivals annual primary produc-tion by phytoplankton in oceans and coastal waters. Phytoplankton play a major role in the carbon diox-ide cycle, although this has so far been only partially quantified. Their growth and decline are therefore of crucial importance to the world’s climate.

To help understand phytoplankton dynamics and pre-dict future conditions, a mathematical model called

BLOOM has been developed and applied since 1977. It simulates the biomass and composition of algae in relation to the amount of nutrients, the underwater light climate and grazing. In comparison to most oth-er primary production models currently in operation, BLOOM considers a relatively large number of algae species, selected by applying an alternative competi-tion principle. The model employs an unconventional mathematical technique; it runs fast and can there-fore be used for long simulations of complex systems. It has been applied worldwide to lakes, channel sys-tems, estuaries, lagoons and coastal seas. Recent applications include the assessment of the planned extension of the Port of Rotterdam, an analysis of the consequences of constructing the storm surge bar-rier in the Venice Lagoon, construction of the Marine Reservoir in Singapore and the environmental impact study on the future of Lake Volkerak Zoom in the Netherlands (whether it should remain a freshwater body or be returned to its original marine status). Al-though the model simulates only part of the aquatic ecosystem, results prove to be accurate enough to be valuable to water managers and decision-makers.


PhDs

Stratigraphy and sedimentary evolution The lower Rhine-Meuse system during the late Pliocene and Early Pleistocene

The subsurface of the Netherlands is a geological archive that can provide information on the inter-relationships of fluvial and marine processes, sea level and tectonic movements and climate change. To access that information, Wim Westerhoff has ap-plied a new lithostratigraphy to the fluvial deposits of the southern Netherlands. This has improved insight into the interrelationships between various sedimentary layers formed between 2.6 and 1 Ma ago. It has also provided a framework for reconstructing the fluvial history of the area. The Rhine, the Meuse and rivers originating in Belgium deposited strata of gravel, sand and clay in the southern Netherlands up to 100 m thick. The study has shown that sediment delivery by the Belgian rivers occurred much earlier than hitherto believed. Continuous sediment supply by the main rivers caused a progressive shift of the main deltaic areas to the north-west. The coastline migrated from the south-eastern part of the Nether-lands to the central North Sea over a period of about

1.5 Ma. Subsidence and sea level movements appear to be the main factors controlling sedimentation patterns. However, most of the sediment transported by the rivers by-passed the Netherlands and this explains the innately fragmentary character of the preserved fluvial sequences. The study concludes that there are many uncertainties in the Early Pleis-tocene chronostratigraphical subdivisions based on these sequences.

The results of the research will feed into subsurface models that can be used in a variety of geoscientific investigations. In addition, the study contributes to a better understanding of river behaviour in response to climate change.

Water lily almost

completely covered

by floating masses

of blue green algae


Floodbasin deposits

(grey clay) of which

the petrographical

composition demon-

strates that the Rhine

delivered sediment

from sources in the

Alpine region to the

North Sea Basin

already during the

Late Pliocene at about

3 million years ago. For more information: [email protected]

PO Box 1772600 MH DelftThe NetherlandsT +31 (0)88-DELTARES (335 82 73)[email protected]

colophon

VIEWS is issued free of charge to all qualified subscribers and is published by Deltares.

Deltares is an independent research institute for water, soil and subsurface issues. It has been established by Delft Hydraulics, GeoDelft, the Subsurface and Ground-water unit of TNO and parts of Rijkswaterstaat. Throughout the world, more and more people are settling in opportunity-rich, but vulnerable, deltas, coastal areas and river basins. That vulnerability is being spotlighted because of rising sea levels, extreme river levels, subsiding soil, and increasing pressure on space and the environment. Deltares develops knowledge for innovative solutions that make living in delta areas safe, clean and sustainable.

for more information: [email protected]

text Direct Dutch Publications, The Haguedesign Teldesign, Rotterdamprint JB&A, Wateringenpaper Printed on paper free of chlorine

deltares views nr 1 2009

Technology

water management delftfews

subsurface management

world of deltares

flood risks

water managers

management team

flood warnings

possibilities of flood