Sea level rise: research into the consequences

Consequences of sea level rise

More flooding, salt intrusion, less fresh water, the slow but sure erosion of the coast: the troubling numbers reflect stories about the disruption of safe and sustainable living in increasingly densely populated cities and deltas.

We work as a knowledge partner for the national government, provinces, municipalities, water authorities, Rijkswaterstaat, other knowledge institutes, engineering firms and a range of NGOs in the Dutch Delta Programme. In that programme, the Netherlands is preparing for the impact of climate change on flood risk management, freshwater supplies, problems with excess water, drought and heat stress. We conduct research on behalf of the Delta Commissioner to see how the Netherlands can best respond to changing conditions with robust climate-adaptation strategies.

For the Netherlands to continue to adapt in the future, strategic choices in the management and use of space in the Dutch delta are required. We also need to keep innovating and experimenting. Staying alert and monitoring developments in Antarctica are crucial for timely large-scale adaptations.

Marjolijn Haasnoot, Deltares expert

Sea Level Rise Knowledge Programme

We are conducting the research on the consequences of sea level rise for, among others, the Delta Programme and the Sea Level Rise Knowledge Programme, which was launched in 2019, in part in response to the findings of the first Deltares report (‘Possible consequences of accelerated sea level rise for the Delta Programme’) .

The primary focus of Deltares here is on the impact of sea level rise on flood risk management (coastal foundation, flood defences), and on freshwater supplies (salinisation issues).

The impact on our economy (particularly ports and shipping), land use (including housing and leisure facilities), agriculture, and nature/ecology are also covered by the research. This provides important decision information for the six-yearly review of the Delta Programme, which will be included in the 2027 Delta Programme.

Programme on the basis of 5 tracks

This programme structures the main knowledge questions on the basis of five tracks:

1. Sea level rise research and knowledge: what can we expect?
2. System reconnaissance studies: how sustainable are the preferred strategies?
3. Monitoring approach: how do we know when to act?
4. Alternatives and adaptation pathways: what is the action perspective for the distant future?
5. Implementation strategy; which communications, changes in behaviour and transitions are needed, and possible, to prepare for this in good time?

Innovation of knowledge about sea level rise

Deltares is globally active in climate adaptation projects and research into the consequences of high and accelerated sea level rise. That puts us in a position to study and monitor the implementation of adaptation pathways and develop that knowledge for the Netherlands. We deploy our in-depth knowledge of the system of water and the subsurface for this purpose. We draw on all the disciplines at Deltares in order to make integrated impact analyses.

Our 3 reports since 2019

All of the reports are available in Dutch. Use the language switch on this page to go to the Dutch article.

1. Report on the ‘Possible consequences of accelerated sea level rise for the Delta Programme’. In late September 2019, as part of the Sea Level Rise Knowledge Programme, Deltares published an initial exploratory study of the potential impacts of accelerated sea level rise on flood risk management, freshwater availability and the coastal foundation of the Netherlands.
2. Report on ‘Strategies for adaptation to high and accelerated sea level rise’ (2020). This report emphasises that the uncertainties at this point in time are too large to either commit to or reject measures. It provides an overview and categorisation of the plans in place to respond to sea level rise in the future. The report introduces four possible solution strategies for the long term:
   1. Protection-closed: protecting the coast from floods and erosion with hard or soft measures such as water defences, sand nourishment or wetlands. River arms will be closed off (with dams);
   2. Protection-open: the same as Protection-closed, but rivers will continue to have open connections to the sea;
   3. Seaward: the creation of new, higher and seaward land to protect the delta from the consequences of flooding;
   4. Flexibility: the reduction of vulnerability to the effects of higher sea level rise by means of water- or salt-tolerant land use (such as floating buildings and infrastructure on piles), raising, spatial planning and/or relocation.
3. Report ‘Analysis of building blocks and adaptation pathways for adapting to sea level rise in the Netherlands (2022)’. On behalf of the Sea Level Rise Knowledge Programme, Deltares studied the measures the Netherlands can take now to cope with sea level rise in the future. In this study, Deltares described 22 possible measures that can be seen as building blocks for future solutions and adaptation pathways. Those measures include hard and soft flood defences, river measures, changes to land use and avoiding the creation of high-risk areas. The building blocks focus primarily on flood protection and they will be extended at a later stage to include building blocks for freshwater supplies. Deltares has explored where these building blocks can be applied, in which combinations, and whether it is wise to start doing so now (in a ‘low-regret approach’). For example, creating space for water storage and the discharge capacity of rivers, raising water levels in peatland areas to prevent land subsidence, and earmarking space for dike upgrades.