Where can we find enough suitable sand for construction activities or replenishment, how can we sustainably manage these stocks, what are good places for other offshore functions such as nature? What are the effects of our offshore activities in these areas? In addition to geophysical data, we also draw on borings that provide geological information.

Efficient foundations that are as sustainable possible are needed for the turbines. We conduct extensive tests in our facilities to model the processes relating to currents and the seabed. We study ways to protect foundations against scouring. The composition of the subsurface also plays an important role here. The installation and presence of wind turbines affect local biodiversity. Working with others, we look for and test solutions, and measure factors such as currents, scour and vibration. In our laboratories, we look at the effects of anti-corrosion treatment on the environment. And we conduct studies to see whether the burial depth of power cables with fibre optics can be monitored to prevent damage. 

Water shortages can cause effects such as the shrinking and swelling of clay, and damage to houses with shallow foundations or wooden piles. By measuring groundwater levels, deformations and/or crack widths, we can learn about the effects of climate change on towns and cities. With meters to measure crack width and photogrammetry, this work can be done over longer periods of time and remotely. We track how damage occurs and whether the chosen solutions work. Quay walls on canals in inner cities are often more than 100 years old, exceeding their technical lifespan. But do we really need to replace them all? Information from measurements of quay deformation, groundwater levels and the locality allows us to validate models and therefore to prevent unnecessary replacement or to make new construction work more effective. In the busy urban environment, smart measurement and monitoring allow us to map the subsurface and processes there while keeping disruption at the street level to a minimum.

We study the composition of the subsurface, in some cases very locally with borings or with extensometers. As a result, we now know that, for example, where there is land subsidence the soil sometimes rebounds. We also measure on larger scales with non-destructive geophysical methods. For example, electromagnetic measurements from drones and helicopters efficiently identify weak spots around dikes and the presence of saline groundwater. 

Land subsidence in rural areas is often the result of oxidation. Peat exposed to oxygen releases CO₂. We measure this in the field on a small scale with a Micro-portable greenhouse gas analyzer or with Eddy Covariance for a larger area. This monitoring is important to determine whether the measures to counteract land subsidence also result in a reduction of carbon emissions. 

With borehole measurements, we can validate fresh-salt levels in models. In this way, we can see where fresh water can be stored. On the provincial scale, we do that from a helicopter with electromagnetic equipment. We use monitoring wells to determine the link between groundwater levels and climate change in order to work on solutions in good time. The validation of our models ultimately results in maps or dashboards that allow management authorities to take action. Measurements from other sources such as environmental services can also be modelled. 

A subsurface with soil life is important, not only for the ecosystem but also to allow enough water to pass through and keep the soil moist. Clean soil means clean groundwater. Our research here ranges from counting earthworms to countering pollution with bacteria or other natural solutions. 

The subsurface plays an important role here. Scour deepens rivers and increases flow rates; dredging also has this effect. It also leads to lower summer levels and therefore lower groundwater levels behind the dikes. River widening – room for the river – is one of the natural solutions selected. Every decision has implications for the bed profile and the functions of the river. We are researching this area with stakeholders in living labs such as Sediment Rijnmond. Through monitoring, research in our facilities and modelling, as in the PRISMA study, dredging in ports is becoming more efficient and sustainable. 

The stability of dikes is important in a densely populated country like the Netherlands. This factor is studied in facilities and in full-scale trials in the field. During dike upgrade operations, successful innovations can be implemented immediately and regulations can be modified. We look at how piping and heaving can cause dike failures, as in the Hedwige polder and near Kampen. In this work, we use equipment such as pore pressure gauges, inclinometers and extensometers, and geophysical techniques such as ERT (Electrical Resistivity Tomography). But stability is also investigated on a large scale. We are currently mapping the subsurface of the entire dike system between Amsterdam and Enkhuizen.

Infrastructure is needed for life and work in the delta. With our knowledge partners, we research and advise on the construction, maintenance and resilience of infrastructure networks. We determine the influence of the subsurface and groundwater on the stability of infrastructure with a range of research and measurement techniques. For the purposes of safety and liveability, we measure and model vibrations caused by traffic and determine how fast trains can travel without causing problems. We use existing fibre-optic cables along the track as measuring instruments for this work. 

Connecting systems with each other will make it possible in the future to convert data into decision information remotely and at any time. We then check those decisions in the field.

We keep data available and usable, drawing on artificial intelligence and the latest computing methods. We invest in Deltares experts and in our measurement and monitoring facilities to meet the challenges.

To preserve biodiversity and our health, it is important to integrate things like Nature-based Solutions. With measurement and monitoring, we can see how the applied solutions work and to what extent this makes the infrastructure in place more sustainable.

Communications are becoming ever more important. Science has to earn people’s trust these days. With measurement and monitoring, we can not only share knowledge and show the effects. Stakeholders themselves can also visualise their actions and efforts. That makes the result more inclusive.