Royal Netherlands Institute for Sea Research
Phone number
+31 (0)113 57 7452
Research Leader
  • Remote sensing, Earth Observation and Geo-Information Science; Big Data
  • Coastal, estuarine & delta systems
  • Geomorphology, biogeomorphology, biophysical interactions & benthic ecology
  • Nature based flood defence & ecosystem based solutions
  • Aquatic systems and water quality

Prof. Dr. Daphne van der Wal

Research Leader

View on the coast

Daphne van der Wal – physical geographer at NIOZ and professor at the University of Twente – observes deltas, coasts and estuaries from space and from the air. ‘That can be done via satellites but also with the help of drones. The use of these remote sensing techniques can teach us a lot about coastal defence, water quality and nature conservation.’


Protection against storms

‘Satellites have the advantage that, in many cases, they allow us to look back over several decades. This is because we have a long history of satellite images which have continually observed a piece of the Earth’s surface in the same way. For example, from satellite images, we can see where coastal vegetation, such as saltmarshes and mangroves, has expanded and where plants have disappeared or where their growth was hampered. We analyse satellite images in relation to coastal protection for the Dutch coast, but also for the coast of Louisiana, for example. Together with modellers, we are examining how vegetation attenuate the waves and trap sediments and can reduce the chance of the land becoming flooded during heavy storms. That allows us to learn what the ingredients are for sufficiently strong coastal defences. Such information is becoming increasingly relevant in light of the changing climate and expected increase in extreme weather.

Looking at muddy waters

‘Satellite images are also well suited for studying the quality of the water and the seabed. For example, we examine the interaction between sediment and the algae and animals that live in the water and seabed. This knowledge is important with respect to, for example, the dredging of estuaries for shipping.’

Radar seeks mussel reef

‘We also use radar images; these can observe, for example, the roughness of tidal mudflats. This way, radar can even be used to map mussel and oyster reefs on tidal mudflats. Now we can also make use of techniques like drones. These provide very detailed spatial information.

With all these forms of remote sensing, we are finding out how our coastal systems work and how they adapt to changing conditions and interventions. We are also learning how coastal processes help us, and how we can protect our coasts.’

Read more +


Specialisation & Current positions

I am a physical geographer, specialized in coastal processes (PhD 1999, University of Amsterdam; postdoctoral research fellow from 1 Oct 1999 up to 1 Jan 2002 at Royal Holloway, University of London). In Mar 2002, I joined NIOO/NIOZ in Yerseke, focusing on remote sensing of tidal (eco)systems. Since Oct 2017, I am also part-time full professor at University of Twente, Faculty of Geo-Information Science and Earth Observation (ITC). 

Publications can be found at my ORCID


Remote sensing of tidal (eco)systems

The central theme of my work is to assess interactions between organisms (such as saltmarshes, algae, shellfish) and their environment, shaping the estuarine, delta and coastal landscape, including both the bottom sediment and the water column. Topics also include the response of estuarine and delta systems to (climate) change and human impact, as well as risks (e.g., flooding) and services (e.g., nature-based flood risk reduction) of the coastal zone.

Current research topics

  • Saltmarsh and mangrove development
  • Solutions for nature-based flood risk reduction
  • Dynamics and management of (intertidal) sediments
  • Structuring and functioning of benthic fauna communities
  • Benthic-pelagic interactions in tidal systems
  • Primary production of tidal flats and waters
  • Suspended sediments and sediment transport in coastal and estuarine waters

Methods & techniques

I use remote sensing techniques and geo-informatics and data science to investigate coastal and estuarine systems and processes:

  • statistical modelling, use of radiative transfer models, and big data analysis with remote sensing data (radar/SAR, optical and TIR satellite data, hyperspectral airborne/drone data and LIDAR airborne data, near-surface and field spectroscopy/measurements) for retrieval and forecasting
  • spatial analyses in Geographical Information Systems (GIS)
  • (time-series) analyses of remote sensing data using cloud platforms
  • combination of earth observation with field surveys and experiments, and (hydrodynamic) models


Selected projects (at NIOZ)

- NWO SALTGARDEN. See news on this trilateral Wadden Sea project. My role: co-applicant.

-Output Remote Sensing work package of a NWO NWA North Sea project on offshore wind parks. See article: Brandao et al (2023)

- Contribution to NWO NWA Blue Route small project on extreme drought, 2023, see here

- STW Perspective AllRisk – Implementing new flood safety norms. Project Foreshore Ecosystems Management. My role: co-applicant of project B (Dynamics in hydraulic loads). PhD candidate at NIOZ/RUG: Beatriz Marin Diaz (joint supervision NIOZ/RUG: Tjeerd Bouma, Han Olff, Laura Govers, Daphne van der Wal).  See Beatriz' PhD thesis, and movie. See also the programme overview and programme outcome.

- NWO/NSO Ruimteonderzoek, “Saltmarshes under stress: thresholds for saltmarsh dynamics from global satellite data” (MARSH). See NWO project output.

- Satellite remote sensing of microphytobenthos in the Wadden Sea: analysis of 18 years of MODIS data , for Deltares, 2021.

- EU FP7 SPACE - FAST "Foreshore Assessment using Space Technology". Consortium Deltares, University of Cambridge, NIOZ Royal Netherlands Institute for Sea Research, University of Cadiz, GeoEcoMar.  My role: work package leader WP3: Remote sensing. PhD candidate at NIOZ on this project: Bas Oteman,  started 2014 . See Bas' PhD thesis.  See also the overall project outcome.

- NWO/NSO Ruimteonderzoek: “Benthic diatoms as indicator for ecosystem structuring in shallow tidal waters.  PhD candidate at NIOZ on this project Tisja Daggers, started 2013.  See Tisja's PhD thesis

- NWO/NSO Ruimteonderzoek: "Consequences of global change for ecosystem engineering of shellfish". PhD-candidate at NIOZ on this project Sil Nieuwhof, started 2012. See Sil's PhD thesis

- Benthic invertebrates (macrofauna) of the shallow subtidal areas (van der Wal et al., 2017) and intertidal areas (van der Wal et al., 2017) of the Westerschelde estuary, for Rijkswaterstaat.




Results from the NWO project Saltmarshes under stress

Laengner, M.L.; van der Wal, D. (2022). Satellite-derived trends in inundation frequency reveal the fate of saltmarshes. Frontiers in Marine Science 9, 942719.

Laengner, M.L.; Siteur, K.; van der Wal, D. (2019). Trends in the seaward extent of saltmarshes across Europe from long-term satellite data. Remote Sensing 11(14), 1653.


Results from the EU FAST project

The EU FP7 project FAST (Foreshore Assessment using Space Technology), 2014-2018, has developed services to help design nature-based flood risk strategies in foreshores, based on earth observation data and big data analysis capabilities.  The MI SAFE downstream service is currently not online anymore, but the data can be found here and the metadata can be found here

Read more on EU FAST in the associated article on this Copernicus downstream service for coastal needs.

See  the results of the EU FAST project in the project synthesis report "Earth Observation and the Coastal Zone, from global images to local information".

Take a tour around the Danube Delta in Romania, one of the field sites in the EU FAST project!

See our instructional videos on field techniques, for example on the use of sedimentation sensors, as used to assess lateral saltmarsh cliff erosion in Van der Wal et al. (2023), and vertical sedimentation/ erosion in Willemsen et al. (2018), Hu et al. (2018), Hu et al. (2017) and Hu et al. (2015).

Watch the instructional video on using the sedimentation sensors:


Linked news

Wednesday 08 May 2024
Joint grant from the Netherlands and Germany for 3 NIOZ studies on Wadden Sea
The Netherlands and Germany are jointly investing €15 million in research projects aimed at effective protection and management of the Wadden Sea. NIOZ researchers are involved in 3 of the 5 awarded projects, in which they will work, among other…
Thursday 18 April 2024
Turbid waters keep the coast healthy
To preserve the important intertidal areas and salt marshes off our coasts for the future, we need more turbid water. That is one of the striking conclusions from a new study conducted by a Dutch-Chinese team of researchers and published today in…
Wednesday 08 November 2023
How do plants outside the dikes keep up with sea level rise? They build a growing creek landscape
Salt marshes are hugely important natural areas on the seaward side of our dikes. They are home to plants and animals, they store a lot of CO2 and they protect the coast against the force of the waves. However, these salt marshes face threats from…
Wednesday 10 May 2023
Salt marshes protect the coast – but not where it is needed most
Salt marshes provide multiple ecosystem services, one of those is protection of the coast against flooding. This is especially important in low-lying countries like the Netherlands. Scientists from the University of Groningen and the Royal…
Tuesday 18 May 2021
Grazing by herbivores contributes to coastal protection
Grazing by cows and small herbivores like hare and geese can help reduce the erosion of vulnerable coastal salt marshes and therefore contribute to nature-based coastal defense. This conclusion was published in a peer-reviewed paper by ecological…
Wednesday 17 March 2021
Blueprints for future coastal protection shaped in geological past
The colonization of mudflats and marshes along the Dutch coast by algae and plants, reveals how developing lifeforms changed landscapes on Earth 500 million years ago. Research on these changing landscapes by scientist Roeland van de Vijsel (NIOZ and…
Tuesday 16 March 2021
Up-close and from space: monitoring stress in salt marshes
Salt marshes are not only important habitats for plants and animals, they also offer protection against flooding by damping the waves. Safeguarding these services provided by the marshes starts with monitoring. Possible shifts in this diverse…
Tuesday 23 February 2021
Understanding microscopic life in the sediment in estuaries with satellite images
Intertidal flats in estuaries, like the Oosterschelde and Westerschelde, contain an enormous diversity of microalgae and cyanobacteria. This small life is also called microphytobenthos and is an important food source for shellfish, worms and…
Monday 19 February 2018
Zelforganisatie onderwaterplanten houdt rivieren gezond
Onderwaterplanten spelen een essentiële rol om rivieren en waterlopen gezond te houden. Biologe Loreta Cornacchia van het Koninklijk Instituut voor Onderzoek der Zee (NIOZ) ondervond dat de waterplant sterrenkroos een regelmatig verspreid 'klonterig'…
Friday 09 June 2017
Langzamer herstel kondigt kantelpunten aan in kustecosystemen
~ ENGLISH version below Dutch version ~ Ecosystemen kunnen plotseling verloren gaan wanneer de druk te groot wordt. Het voorspellen van het kantelpunt is dan ook van groot belang. Wiskundige modellen lieten al mogelijke waarschuwingssignalen zien.…

NIOZ publications

Linked projects

UUNIOZ_Defending our coast: Facilitating coastal ecosystems to respond to sea level rise
Johan van de Koppel
Utrecht University
Project duration
1 Jan 2021 - 31 Dec 2025
FAST_Foreshore assessment using space technology
Daphne van der Wal
European Community
Project duration
1 Jan 2014 - 31 Dec 2017
NWO_BenthicDiatoms as indicators for ecosystem structuring in tidal shallow waters
Daphne van der Wal
Netherlands Organization for Scientific Research
Project duration
1 Jul 2013 - 1 Feb 2018
NWO_Ruimteonderzoek_Consequences of global change for ecosystem engineering of shellfish
Daphne van der Wal
Netherlands Organization for Scientific Research
Project duration
1 Jan 2012 - 30 Aug 2016
MARSH_Saltmarshes under stress
Daphne van der Wal
Netherlands Organization for Scientific Research
Project duration
1 Jul 2016 - 30 Jun 2020