It was a great honor to be the 2021–2022 Henry Darcy Distinguished Lecturer. I am truly grateful to the nominators, the selection committee, the NGWA staff, and Indiana University, who relieved me of my teaching duties for two semesters.
I offered three talks, entitled:
The Groundwater Foundation received over 100 invitations from 20 countries. In total, I gave 60 lectures, 25 of which were in-person. The Darcy lecture series remains to be prestigious, but in 2021–2022, it served a special role in combating the pandemic by encouraging us to keep learning, keep teaching, and keep researching. Many organizations relied upon the Darcy lectures to add some sizzle to the weekly departmental colloquium or the yearly symposium of state-level professional organizations. The in-person lectures were overwhelmingly welcomed by students who have felt isolated during the pandemic and craved in-person interaction.
I made a significant effort to include undergraduate institutions and those with a large percentage of students from historically underrepresented groups. The pandemic has hit students much harder than the faculty. At the Grand Valley State University, Peter Riemersma brought over 100 undergraduates to my lecture and shared some of the students’ two-page reports. It is gratifying that most students say my climate change-water resources talk was inspiring. At the University of Toronto, one undergraduate student wrote to me, “I want to thank you for your advice on my future career over the lunch talk. I feel a lot better after talking with you.”
The organizations that I visited included top-ranked private and public research universities, undergraduate colleges, national laboratories, federal agencies (NSF, EPA, USGS), and industry. I gave virtual talks in the UK, Germany, and Saudi Arabia, and I spoke at the annual meetings of the Geological Society of America, the International Association of Hydrogeologists, The Geological Society (of London), and, of course, the Ground Water Week and Groundwater Summit.
At the University of Toronto, one undergraduate student wrote to me, “I want to thank you for your advice on my future career over the lunch talk. I feel a lot better after talking with you.
Zoom made accounting easier—more than 4,000 attendees, or as one organizer cleverly said, 4,000 devices logged on for the lectures. Some organizations doubled up the Darcy Lectures with their own distinguished lecture series. The most prominent was the National Science Foundation’s Distinguished Lecture series, to which the Geoscience Directorate invited me in October 2021.
I also gave a lecture for Chevron Corporation’s companywide lecture series “Fellows Learning Forum.” Other institutional distinguished lecture series included the Frontiers in Geoscience Colloquium Series at Los Alamos National Laboratory, and the Earth and Environmental Sciences Area’s Distinguished Scientist Seminar Series at Lawrence Berkeley National Lab.
The virtual format made the Darcy lectures reach further than they normally would. In the UK, the Universities of Cambridge, Oxford, and St. Andrews organized a colloquium consortium called Earth to Earth. The USGS offices have nationwide Water Mission Area monthly talks. The EPA’s Office of Research & Development organized a Darcy lecture that was open to all its divisions. The Deutsch IAH and German Federation of Groundwater organized a Germany-wide seminar series. Since the pandemic prevented international travel, we arranged three broadcasts in November 2021 and three more in March 2022 to reach places as diverse as Australia, Chile, Colombia, New Zealand, France, Israel, Estonia, Ethiopia, Indonesia, Turkey, The Philippines, Spain, South Africa, Slovakia, Peru, Nigeria, Mongolia, Mexico, The Netherlands, and Brunei Darussalam.
Further, everyone wanted to ask the Darcy lecturer, “What are the research trends in groundwater sciences learned from these trips and conversations?” I spotted two: climate change mitigation and machine learning.
The lecture tour offered me an opportunity to connect with many colleagues and kept me apprised of activities in our field. It was a humbling experience. The tour not only gave me a chance to talk about my research but also proved inspiring for me. It is clear the hydrological science field is vibrant at all levels, as shown by the enthusiasm for the Darcy lectures at national and international organizations, at the national chapters or regional section levels, and statewide organizations. Further, everyone wanted to ask the Darcy lecturer, “What are the research trends in groundwater sciences learned from these trips and conversations?” I spotted two: climate change mitigation and machine learning.
On climate change, some campuses appear to be transitioning from documenting climate change to “actionable research” by ramping up “problem-focused” research programs. Various climate change abatement strategies are at the water-climate-energy nexus and would profoundly transform the hydrological sciences.
Storing hundreds of billion tons of CO2 in deep saline aquifers, minerals, and soils worldwide requires the characterization of aquifers, modeling multiphase reactive flow and reactive transport, and monitoring potential leakage and impacts on freshwater resources. The energy transition from fossil fuels to renewable and clean energy requires mining critical metals, which could severely impact water quality in regions where water availability and quality are already under stress.
It appears that everyone is applying machine learning to hydrological problems. Some colleagues made me aware of machine-learning tools that are available to us in IT industries. We do not need to do “programming” in the traditional way but to apply toolkits to our problems. This makes applications much easier. However, I hope that our community realizes early the potential pitfall of using machine learning as a black box, like what happens sometimes to geochemical modeling, and develops a curriculum to address it.
Going forward, I think the Darcy lectures series can play an even more prominent role in promoting our profession and attracting students to the hydrological sciences. On one hand, Zoom allows us to reach a wider audience both domestically and abroad, in meaningful ways as demonstrated by engaged audience questions. On the other hand, many departments are struggling with attendance at their weekly colloquium. The Darcy lectures offer topics of significance and relevance (water resources) and the prestige established by distinguished lecturers through the years. There is the potential that the hosts can make the Darcy lecture one of the gathering events of the year and attract a large audience.
I would like to thank all my hosts, who made a tremendous commitment of time and energy. Many hosts are former Darcy lecturers, whose fellowship and camaraderie I really enjoyed. I would also like to thank some of our most respected hydrological scientists for their support. Steve Ingebritsen of the US Geological Survey sent this comment through Zoom: “Brilliant lecture, Chen Zhu! I love the way you built from basic science to global challenges.” In March 2022 when fatigue set in, Bill Alley of NGWA introduced me and attended all my three broadcast talks.
Henry Darcy, who devoted his life and career to providing clean drinking water and sanitation to his fellow citizens, with a humble and diplomatic demeanor, provides a fitting eponym for this lecture series. I want to thank the Groundwater Foundation for running the Henry Darcy Distinguished Lecture series to inspire the next generation of hydrological scientists and engineers, who will not only embody Darcy’s pursuit of knowledge and skills but also his devotion to the public good.
Chen Zhu
Bloomington, Indiana, USA