Over nearly 50 years of publication, Terra et Aqua has benchmarked innovative maritime solutions through more than 150 issues. Articles are available here as well as in IADC’s Knowledge Centre.

Terra et Aqua 156
Published October 2019

Terra et Aqua 156 – complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

Modelling the waterjet cable trenching process on sand dunes

Cables for offshore wind farms in the North Sea are buried for protection. A highly variable seabed topography influences the trenching process in sandy soils. A model has been developed to estimate the influence of sand dunes on the trenching process.

Interview: Henk Nieboer

After 30 years at Witteveen+Bos, Henk Nieboer has moved on from the engineering and consultancy firm to focus his expertise into his current roles as director of EcoShape and founder of Adaelta.

14 innovations face off for Safety Award 2019

Each year, IADC gives a safety award to one exceptional innovation which proves it is the best in its class. This year, 14 innovations addressing challenges faced within the dredging industry have been nominated.


Sustainable management of the beneficial use of sediments: a case studies review

Authors: Luca Sittoni

CEDA’s Working Group on Beneficial Use aims to inspire sediment stakeholders and practitioners by describing the importance of sediments in the context of sustainable development and sharing a curated selection of case studies.

Published September 2019

Terra et Aqua 155 – complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

Can a ‘Mud Motor’ of dredged sediment help enhance salt marsh development naturally?

Following the Building with Nature concept, a pilot study was conducted introducing finegrained dredged sediments as a semicontinuous source of mud into a shallow tidal channel, naturally dispersing sediment to nearby mudflats and salt marshes.

Should the dredging industry establish common standards for crew transfers?

Crews routinely perform vesseltovessel transfers, ensuring a project continues seamlessly. But the operation is not risk free. A roundtable of IADC members shared ideas on how to improve procedures to make crew transfers safer.

Interview – CEO of DEME Group, Luc Vandenbulcke

‘What will “sustainability” be in ten years? Our industry needs to be prepared for that.’ Luc Vandenbulcke kicked off 2019 in his new role as CEO of DEME Group. After 21 years working within the group, with 14 of those years starting up, leading and growing the group’s offshore subsidiary, he is now heading the company’s future as it navigates the evolving processes of sustainability.

Numerical investigation of the head and unsteady flow characteristics of a dredge pump loading high-concentration sands

The head of a dredge pump is an important performance parameter and a strongly fluctuating head may affect the operating stability of the pump unit. The IADC Young Author’s Award paper analyses unsteady characteristics of pump performance to improve control of the dredge pump.

Cover Terra et Aqua 154
Published June 2019

Terra et Aqua 154 – complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

Can a lake’s ecology be restored with unwanted sediment?

In collaboration with the Natuurmonumenten (the Dutch Society for the Preservation of Nature), Boskalis constructed the Marker Wadden. The archipelago situated within the Markermeer enables processes which revitalise the natural ecology.

Challenges of optical backscatter monitoring in mixed sediment environments

Popular instruments in the field, optical backscatter instruments (OBS) are used to measure suspended sediments. The sensitivity of OBS measurements in relation to grain size and the applicability of OBS measurements in mixed sediment environments is analysed.

Interview Patrick Meire – ‘We must try to use the best of the science to manage the environment.’

Authors: Patrick Meire

Ecologist Patrick Meire has been researching the Scheldt for decades in the hope of implementing solutions which undo the damage caused by humans, industry and natural processes.

Fehmarnbelt: A green link between Germany and Denmark

To connect Scandinavia with Germany, the world’s longest immersed tunnel will be built. The Fehmarnbelt will close a major gap in the European transport network while fostering the development of new nature and recreational landscapes.

Published May 2019

Terra et Aqua 153 – complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

Can a preliminary model describe CSD spillage due to centrifugal advection?

Depending on its size and installed power, a Cutter Suction Dredger is capable of cutting a wide range of soil types. Although precise and relatively efficient, a CSD can spill significantly. The authors propose a preliminary model which describes spillage due to centrifugal advection.

Are the days of the double-walled pump housing numbered?

Authors: Ewout van Duursen

For several decades, the preferred solution for isolating dredging pumps within a vessel has been double-walled pump housing. To bypass this housing type’s intrinsic problems, Damen formulated an alternative.

What happens when individuals step up safety during dredging activities?

By viewing routine processes and situations through a continuous lens of safety, individuals can help make operational processes on water or land safer. Eight solutions nominated for IADC’s Safety Award demonstrate the benefit of this approach.

Terra et Aqua 152
Published November 2018

Terra et Aqua 152 – Complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

What value does a marine contractor create for its stakeholders?

Externalities traditionally fall beyond the scope of contractors, leading to stakeholder value creation and corporate value creation being viewed as separate concepts. The time has come to internalise externalities as a force of corporate value creation.

Interview: Mark van Koningsveld ‘If you focus on primary objectives only, then you will pay in sustainability’

Mark van Koningsveld’s quest for a sustainable dredging industry takes to the front of the classroom as he begins his new role as professor of Ports & Waterways at TU Delft.

Can a project checklist lead to successful dredging management?

A recurring situation observed during the course of a project: the same issues which arise are experienced differently by different parties. A commission was founded to determine the reason and if possible, propose a solution.

Which slurry transport regime should be used and why?

Authors: Sape Miedema

With five possible flow regimes to choose from for slurry transport, selecting just one can require consideration. Fortunately, one of these regimes has a simple criterion: a ratio of the particle diameter to the pipe diameter.

Published September 2018

Terra et Aqua 151 – complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

Can Workability be Enhanced by Operational Wave Modelling?

IADC’s Young Author Award winner François De Keuleneer and co-authors Joris de Vroom and Arjan Mol discuss the Workability Tool which ensures captains of specialised vessels can make informed decisions to dredge during favourable wave conditions.

Interview: Tiedo Vellinga – ‘There should be a shift in the way of thinking about designing infrastructure’

Authors: Tiedo Vellinga

A newly appointed Professor Emeritus at TU Delft and former project manager at the Port of Rotterdam Authority, Tiedo Vellinga discusses his role as a bridge between academia and practice and its impact on the direction of port development.

How navigable are fluid mud layers?

Safe navigation through ports and waterways is determined by the space available under a ship’s keel, but a seabed of fluid mud can get in the way.

Published April 2018

Terra et Aqua 150 – complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

1DH Model Predicts Transport and Sedimentation Inside a Hopper

A one-dimensionalhorizontal modelling tool which accurately predicts the overflow of sediments and bed layer distribution inside the hopper of a Trailing Suction Hopper Dredger is introduced.

Interview: ‘Can ports face extreme vessel growth by themselves?’

The International Association of Ports and Harbors’s Patrick Verhoeven discusses the major topics facing the world’s ports as they prepare for the future as well as ways ports can adapt to the ever-growing scale increase of ships.

How can the dredging sector join the global shift towards sustainability?

A paradigm shift is being increasingly embraced within the dredging industry. The traditional engineering approach is becoming a holistic approach in which the ecosystem is leading and values for people, profit and planet are integrated in an interdisciplinary manner.

Is high quality sediment monitoring worth its weight in gold?

Dredging activities often result in the suspension of sediment into the water column in the vicinity of the activity. Sediment release to the aquatic environment and the effects of this release are often the prime environmental concern associated with dredging.

Published January 2018

Terra et Aqua 149 – complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

Transport of Pipeline Optimisation

Formulated by employees of Jan De Nul Group, the solution which won the Safety Award 2017 upgraded each facet of the pipeline transportation process, including from the activities performed in storage facilities as well as while travelling to faraway project locations.

Towards a Green Maritime Technology

The growing awareness of the need for diversified energy sources has collided with the maritime industry. Research initiative JOULES was created to assess the viability of a vessel being 100 per cent green by increasing efficiency and reducing emissions.

Towards Sustainable Port Development

An ecosystem services assessment of Port Botany’s expansion identifies the project’s economic, environmental and socio-economic impacts for a universal stakeholder guide which ensures sustainable development.

Published September 2017

Terra et Aqua 148 complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

13 Nominations in the Running for IADC’s Safety Award 2017

Safety is the number one priority during dredging operations and IADC’s Safety Award aims to promote awareness through innovation. Thirteen nominations are in the running to receive the 2017 Award.

An Improved Integrated Approach for Optimising Shipping Channel Capacity for Australian Ports

Authors: Simon Mortensen

The continuing surge in vessel sizes is putting increased pressure on port authorities worldwide. Experts recount the implementation of innovative modelling for maintaining channel depths at the ports of Brisbane and Geelong, Australia.

Some Proven Benefits of Polymer Use in the Treatment of Sediments in Recent Dredging Projects

To show the success of polymer use in highly contaminated areas, two recent projects are presented: at Port-La-Forêt harbour in La Forêt-Fouesnant, France and at the Kishon River seven kilometres downstream from Haifa, Israel.

Randle Reef Sediment Remediation: Current Status of Construction and Next Steps

Randle Reef at Hamilton Harbour, an Area of Concern (AOC), is the largest site in Canada contaminated with Polycyclic Aromatic Hydrocarbons (PAHs). A collaboration of municipal and federal entities is working on remediation measures.

Terra et Aqua 147
Published June 2017

Terra et Aqua 147 – complete issue

Read the complete issue containing articles, upcoming events, an interview and book review.

Innovative Modelling: A Tool for Coastal Developments

The Port-La Nouvelle harbour, located in an inlet between Bages-Sigean lagoon and the Mediterranean coast is home to complex hydrodynamics. An innovative package of five interacting hydro-sedimentary numerical models was developed to assess a port expansion project in the area.

Safety on Site

One in five fatal accidents occur in construction and a high percentage of it involves a man on the ground. This article explains how companies can significantly reduce the number of potential accidents on the construction site by implementing strict safety protocols; separating pedestrians and machinery on the site; and what employees can do to maintain a safe working environment.

ReefGuard: A Scientific Approach to Active Reef Rehabilitation

ReefGuard, a mobile coral breeding facility provides a highly controlled environment to aid in integrating the breeding and outplanting of corals. This article gives a detailed look into how proven small-scale coral breeding techniques can be scaled-up and applied in practice to promote environmental gain around marine infrastructure projects.