Welcome to Inge de Graaf's research group on Groundwater sustainability and crop production at Wageningen University
contact: inge.degraaf@wur.nl. (x) @Inge_deGraaf
Earth Systems and Global Change group, Wageningen University and Research, Netherlands.
Hello! I am Inge de Graaf. I am a hydrologist and associate professor at Wageningen University in the Earth Systems and Global Change group. I use numerical modelling to better understand large-scale groundwater systems and study how much groundwater is available worldwide for people and nature, now and in the future.
Welcome to my website. Here you will find the latest news and background on the work done in my research group on groundwater modeling, groundwater use, and sustainability.
Research Group
Groundwater Sustainability and Crop Production
Inge de Graaf (group leader)
Bryan Marinelli (PhD)
Floris Teuling (PhD)
Sida Liu (postdoc)
Fatemeh Karandish (postdoc)
Lisanne Nauta (technical staff)
Karun Datadien (technical staff)
bowling event (2024)
Former:
Tijmen Willard (PhD)
Wahdan Syaehuddin (MSc student)
Haochen Yuan (MSc student)
Miranda Xiao (MSc student)
This group is co-funded by the European Research Commission Starting Grant
MISSION
Why: A better understanding of large-scale groundwater dynamics and its interactions with other parts of System Earth is the keystone to better quantification of groundwater availability and the impacts of water use now and in the future.
How: We strive to improve our understanding of the groundwater system, through integrated hydrological modelling (coupling groundwater, surface water, and atmospheric processes) at the global-to-continental scale.
What: A specific focus of our group lies on quantifying how much groundwater is sustainably available for crop production and to what extent this will support sufficient crop production, needed to maintain global food security, now and in the future. We develop and use a novel modelling framework that combines groundwater, surface water, and crop growth modelling globally solving the water and energy balance at the global-to-continental scale and estimating crop growth and production using different climate and water use scenarios. We focus on the development of adaptation scenarios that aim on reducing and preventing the negative impacts of water use and increase the availability of (ground)water that can be used in a sustainable way.
In particular, our research is directed to contribute to:
(1) A better quantification of how much groundwater is sustainably available.
(2) An improved understanding of the current and future impacts of groundwater use.
(3) An understanding to what extent crop production can be supported by sustainable use of groundwater.
(4) The development of an advanced integrated groundwater-surface water-energy model.
(5) The development of new and advanced model evaluation strategies.
Team News & Insights
Groundwater: A Vital Lifeline for Healthy Ecosystems
Read the paper here: https://doi.org/10.1029/2024WR037519
This is the first paper if Bryan's PhD project
Groundwater plays a key role in sustaining surface water bodies, especially during low-flow periods. A global study (1960–2010) compared two methods to estimate environmentally critical groundwater discharge, the flow needed to maintain ecosystem health:
Presumptive Standard: Maintains a fixed proportion of groundwater discharge at all times.
Q*: Focuses on low-flow periods with a critical flow threshold.
Key findings:
The Presumptive Standard detected more frequent and severe violations, but both methods showed similar spatial hotspots.
During low-flow periods, both methods estimated comparable violations, highlighting the critical role of groundwater.
Including groundwater in environmental flow assessments is especially crucial for regions with high groundwater demands and drier climates.
Protecting groundwater discharge is essential for resilient ecosystems, particularly in water-scarce regions.
Can Saving Water Make Droughts Worse? The Irrigation Efficiency Paradox
Boosting irrigation efficiency (IE) to save water may seem like a no-brainer, but it can sometimes backfire. This study found that in China’s Huaihe River Basin, increasing IE sometimes actually worsens drought by encouraging more water use, especially when water is already scarce. When water is plentiful, better IE helps reduce drought, but when it’s limited, higher IE can make it worse. Key takeaway? Water-saving policies should be tailored to local conditions and consider the bigger picture to avoid unintended consequences!
Read the paper here: https://www.sciencedirect.com/science/article/pii/S0022169424016573?via%3Dihub
How deep is the world's groundwater?
Turns out, we don’t know exactly! A new study we contributed to uncovers big uncertainties in global groundwater depth models, which could impact everything from ecosystems to drinking water supplies. We urge better data and models to ensure sustainable water use and fight future shortages. The takeaway? We need clearer insights to protect this hidden, vital resource beneath our feet.
Read the paper here: Uncertainty in model estimates of global groundwater depth - IOPscience
Mountains don’t just store snow—they hide a crucial link between the cryosphere (frozen water) and groundwater!
A new study reveals how melting glaciers and snowpack feed underground water systems, impacting rivers and ecosystems far beyond mountain ranges. This hidden connection is essential to the global water cycle, yet often overlooked. Understanding this link is key to managing water resources in a warming world.
Read the paper here: Cryosphere–groundwater connectivity is a missing link in the mountain water cycle | Nature Water
Inge received the EARLY CAREER AWARD 2023 of KNAW
De Graaf is interested in the future availability of freshwater, a challenge exacerbated by the growing world population and climate change. Using an innovative model linking groundwater-surface water interactions, she has shown that groundwater abstraction has a major impact on nature and that it is particularly important to better understand the interaction between groundwater levels, agricultural irrigation and rivers. De Graaf’s research highlights the challenge involved in using sustainable methods to ensure food security on a global scale.
Twelve young researchers from various scientific domains are presented with the Royal Dutch Academy of Arts and Sciences (KNAW) Early Career Award every year. The award acknowledges their exceptional achievements with a unique work of art and a sum of 15,000 euros. This is the fifth time KNAW Early Career Award has been presented.
Inge about the KNAW Award:
‘The prize comes with a sizeable sum of money. Still, the acknowledgement of my research matters most. It motivates me to continue.'
Is groundwater pumping draining our rivers?
Groundwater pumping is causing rivers to lose water—a process called "river capture." A new global study coming from our team highlights how over-extraction of groundwater intensifies this phenomenon, impacting freshwater ecosystems and reducing river flow. As more water is drawn from underground, rivers can shrink or even dry up, threatening water supplies and habitats. This research underscores the urgent need to rethink water management and protect both surface and groundwater resources in a changing climate.
Read the paper here: https://iopscience.iop.org/article/10.1088/1748-9326/ad383d
Can we predict drought with just rainfall data?
A new study shows that forecasting hydrological droughts isn't just about precipitation—catchment characteristics and human activities play a major role. The research reveals that factors like land use, water management, and soil properties significantly influence drought outcomes, making simple rainfall data alone unreliable for accurate predictions. Understanding these local variables is key to improving drought forecasts and preparing for future water shortages
Read our latest paper based on the excellent MSc thesis of Wahdan
Bryan Marinelli receives the EGU Outstanding Poster Award
Bryan received this award for his poster presented at EGU2023 in Vienna. Congratulations! He presented the first results of his PhD reseach on rivers crossing environmentally critical discharges due to groundwater pumping.
Inge was awarded the Outstanding Early Carreer Scientist Award of the European Geosciences Union
Inge was awarded the Outstanding ECS award of the Hydrological division during EGU2023. She was recognized for her fundamental contribution to the field of large-scale hydrology and groundwater modeling. Have a look at her Award Lecture under 'presentations'.
Read our latest paper on 'Quantifying Groundwater's Contribution to Regional Environmental-Flows in Diverse Hydrological Landscapes'
