"Without data, we remain blind to one of the world’s greatest health risks"
Hydrologist and VUB professor Ann van Griensven has spent years working on one of the most urgent yet often invisible challenges of our time: water quality. Drawing on her expertise in hydrology and water modelling, she studies how natural processes and human activity together affect the quality of rivers, lakes and reservoirs. Climate change, urbanisation and more intensive land use are placing water systems under pressure worldwide, with far-reaching consequences for ecosystems, the economy and public health. Yet reliable data to fully grasp this is often lacking.
Van Griensven’s research begins with that fundamental gap. She develops models and monitoring strategies that provide a clearer picture of water quality and support policymakers in making informed decisions. “Water quality often flies under the radar precisely because data is scarce and unevenly distributed,” she explains. “Yet the consequences are vast: globally, poor water quality is estimated to be linked to half of all child deaths.”
Her current research focuses on untangling the complex interplay between climate, land use and human activity. Van Griensven examines how extreme weather affects rivers and lakes, and how agriculture, industry and urbanisation contribute to pollution. “A major breakthrough has been the recent publication of a global high-resolution water quality and quantity model, capable of simulating both current and future scenarios,” she says. “This model makes it possible to identify sources of pollution, assess risks, and intervene more effectively to protect ecosystems and water services.”
A second key pillar of her work is the way data is collected. Van Griensven combines traditional monitoring with satellite imagery, innovative sensor networks and artificial intelligence. Internet-of-Things sensors, developed at VUB, measure variables such as temperature, turbidity, electrical conductivity, pH and oxygen levels. By deploying these globally and linking them intelligently, a far more complete picture of water systems emerges—one that serves both science and policy.
Citizen science from Dilbeek to Bolivia
Van Griensven is also internationally recognised for her pioneering use of citizen science. By working with local schools and communities, she actively involves citizens in data collection and knowledge-building. Her collaborations span indigenous communities in Chojasivi, Bolivia, local stakeholders around Lake Titicaca, and the Yala wetlands by Lake Victoria—yet just as much with 140 pupils aged 14 to 16 in Dilbeek, who use citizen science techniques to measure water quality in their own surroundings. This approach not only strengthens the datasets but also raises awareness and understanding of water quality—something Van Griensven sees as essential for lasting change and for promoting “environmental justice”.
The societal impact of Van Griensven’s work is evident in concrete initiatives such as UNESCO’s CRIDA approach (Climate Risk Informed Decision Analysis). In collaboration with governments, NGOs and local universities, her team maps out vulnerabilities, risks and possible solutions. In Africa and Latin America, the focus is on regions facing structural challenges—such as informal settlements without proper (waste)water treatment, lack of water rights, weak environmental regulation and the need to strengthen local communities in dialogues with authorities. This joint analysis then forms the basis for identifying feasible interventions, including nature-based solutions. Examples include controlled floodplains along the Scheldt estuary in Kruibeke, or further upstream at Zennegat near Mechelen.
“In Flanders, we’re looking at how nature-based solutions can help improve water quality and biodiversity,” says Van Griensven. “This is done in partnership with the Institute for Nature and Forest Research, the Flemish Environment Agency, and NGOs such as Waterland, GoodPlanet and Natuurpunt.”
“Child deaths from polluted water must become a thing of the past. I hope we’ll see a clear difference within ten years"
A powerful example of combining global thinking with local grounding is the in-depth case study of the Scheldt river basin. This catchment is economically and ecologically vital, yet faces pollution from agriculture and industry, heightened flood risks, habitat loss and invasive species. “The Scheldt encapsulates many of the challenges European regions are currently facing,” says Van Griensven. “That makes it a particularly instructive case.”
Van Griensven’s ambitions for the next 5 to 10 years are clear. First and foremost, she aims to shed light on the enormous global data gap surrounding water quality—with particular focus on Africa, where measurements are still largely absent. Alongside this, she seeks to drive concrete action and solutions through citizen science and collaboration, while further strengthening the link between water quality and health, especially for women and children. “Child deaths from polluted water must become a thing of the past,” she says. “I hope we’ll see a clear difference within ten years.”
The international recognition her work is receiving is opening doors to new opportunities and collaborations. Support from the AXA Research Fund allows her and her team to pursue highly ambitious science, including the development of a global model and engagement with international frameworks such as UNESCO-IHP (Intergovernmental Hydrological Programme), UNESCO Biosphere Reserves and the UNEP World Water Quality Alliance.
Ann van Griensven is Professor of Hydrology and Water Quality at the Vrije Universiteit Brussel, where she is Head of the Department of Water & Climate. She holds the AXA Chair on Water Quality and Global Change and is UNESCO Chair on Open Water Science and Education. Her research combines data-driven models, measurements, and citizen science to better understand water quality and translate this into policy and societal impact.
What’s in a name: The AXA Chair
Ann van Griensven’s research programme is supported by the AXA Research Chair on Water Quality and Global Change. The chair, worth €1 million and funded by the AXA Research Fund, runs over a 5 year period and is hosted at the Vrije Universiteit Brussel. The funding supports both fundamental and applied research, the development and deployment of monitoring tools, citizen science, international data collection, advanced model development, and the training of young researchers, including PhD candidates and postdoctoral fellows.
The chair explicitly promotes collaboration between universities, governments, NGOs, industry and citizens, with the aim of translating scientific knowledge more swiftly into policy and practice. Through this chair, AXA builds on its longstanding commitment to academic research in Belgium. Over the past 15 years, the AXA Research Fund has allocated nearly €9 million to Belgian research projects, including several focused on environment and climate—though only one AXA Chair had previously been awarded in Flanders.
For Ann van Griensven, the chair represents not just recognition, but also the freedom and trust to further pursue her ambitious vision on water quality and global change. “The AXA Research Fund gives me complete freedom,” says Van Griensven. “They seem genuinely impressed by our transdisciplinary approach, working with local communities, citizens, NGOs and governments. Our work even inspired AXA to launch its new ‘Human Progress’ call. They’re not interested in funding science that stays locked inside the lab—they see the science-policy interface as absolutely crucial.”
