Marc Bierkens has made truly seminal contributions to the field of global hydrology and groundwater sustainability. With this recognition, he joins a group of renowned hydrologists whose work has had lasting scientific and broad societal impacts.

Marc is probably best known for his work on global hydrological modeling and studying the effects of global change on groundwater resources. However, Marc’s research covers all spatial scales, from the local to the global, and he has made seminal contributions at each of these scales.

His early work was at the interface of soil physics and groundwater, but over the years he branched out to tackle problems that are characterized by regional to global scales. With his leadership and vision, he now leads one of the leading research groups in the field of large-scale hydrology. A major achievement of Marc has been the development of PCR-GLOBWB, which is one of the first global hydrology and water resources models that fully integrate human water use. This model is now used to study global water availability and water demand. The scientific and societal relevance of this modeling tool is probably most evident from the fact that it has been used in over 400 publications and supports several web services that open up water resources analysis to the larger public. Most notable are the Global Water Risk Atlas from the World Resources Institute and the World Water Map from the National Geographic Society.

Marc has unselfishly served the community as editor of scientific journals, organizing international meetings, and contributing to scientific sessions. He has been an editor of Water Resources Research since 2017 and served as the associate editor from 2009 to 2016. He has invested tremendous energy into mentoring and educating young hydrologists. Many of Marc’s students and postdocs have received major international recognition. Marc’s dedication and motivation are perhaps best described by his letter writers, who call him energetic, exciting, dynamic, gracious, generous, very productive, full of encouragement, and good humored. This clearly illustrates Marc’s love for science and the enthusiasm with which he does research with his team.

—S. Majid Hassanizadeh, Stuttgart University, Stuttgart, Germany; and Niko Wanders, Utrecht University, Utrecht, Netherlands

I am grateful and excited to be this year’s recipient of the AGU Hydrologic Sciences Award and humbled when I see the winners who preceded me. For me, 2023 has been a true annus mirabilis, with three recognitions in a row. I want to thank Majid and Niko for their kind words and for nominating me. I also want to thank those who supported me in this nomination. For me it is a special honor to be recognized by the hydrologists of AGU. During my hydrology studies at Wageningen University, I literally spelled the Water Resources Research “Trends and Directions in Hydrology” issue, 22(9S), and remember being in awe about the great research and deep insights on display. Since then, I have traversed quite a range of different fields, some of which are part of that issue: point-process modeling, time series analysis, geostatistics, sampling and monitoring design, stochastic subsurface hydrology, upscaling, soil hydrology, ecohydrology, and water quality. I finally came home to large-scale hydrology when landing as chair in hydrology at Utrecht University. During that journey I enjoyed the help of great mentors. I would like to mention Paul Torfs, Carlos Puente, Frans van Geer, Peter Burrough, Jaime Gómez-Hernández, and Eric Wood. When I set my self up in Utrecht, I made the decision to pursue the building of a global hydrological model including human water use, even though several other models were already around. It turned out to be the right thing to do. It allowed us to study the hydrological cycle as part of the Earth system and look at a myriad of global change issues related to water, notably the depletion of global groundwater resources. I am grateful to the many Ph.D. students and postdocs, as they are the ones who did the actual work. I specifically must thank the people who helped me build the large-scale hydrology group over the past 15 years: Rens van Beek (the godfather of PCR-GLOBWB), Derek Karssenberg, Edwin Sutandudjaja, Yoshihide Wada, Walter Immerzeel, Niko Wanders, Inge de Graaf, Michelle van Vliet, and Gu Oude Essink. Most of you have gone on to build reputed research groups of your own. I could not wish for anything more. —Marc F. P. Bierkens, Department of Physical Geography, Utrecht University, Utrecht, Netherlands

For contributions in understanding hydrological processes across scales and the modeling and analysis of climate change and human water use on global groundwater stocks.