Luna B. Leopold Early Career Award
Citation
It is a pleasure to write this citation for Dr. Hongbo
Ma, recipient of the 2023 Luna P. Leopold Award.
In the 9 years since Hongbo completed his Ph.D., he has
accomplished more to advance the field of sediment transport theory
than was achieved in perhaps the previous 35 years. In a series
of three papers published between 2017 and 2022,
Hongbo provided novel theoretical insight into nonlinear transport phenomena by
combining detailed field measurements with laboratory flume data, so advancing
our physical understanding of the linkages between grain size, shear stress,
and sediment flux.
Moreover, Hongbo has demonstrated an extraordinary application of his work to society, including the novel finding that channel bed degradation downstream of dams can lead to enhanced flooding risk. This is one of the more startling and
counterintuitive ideas presented to date in the discipline of fluvial
morphodynamic research.
Hongbo enthusiastically led extensive field studies of the
Yellow River (in China), with one of his first findings showing, through direct
measurements, that the bed features dunes that possessed abnormally large
length-to-height ratios. With this
observation, Hongbo demonstrated that the exceptionally high sediment flux of
the very fine grained Yellow River is in part a consequence of enhanced
efficiency of boundary shear stress; specifically, that low-relief dunes
significantly reduce form drag and render nearly
all boundary shear
stress available for sediment transport. Hongbo then retooled
a timeless sediment transport
equation (Engelund-Hansen) to account for low-relief dunes and produced a new
physically based sediment transport relation, validated with field data. The breakthrough from this research is a
formula grounded in physics that is transferable to other fine- grained
systems.
The Leopold Award
is named in honor of a scientist “who engaged with and nurtured early-career
scientist throughout his distinguished career in hydrology and fluvial
geomorphology.” Hongbo reflects these
virtues, as he excels in mentoring and drives civic engagement. He is a natural and gifted educator, and an effective communicator who actively
seeks student involvement. His patience is
bottomless, and he deeply cares about helping students acquire an intuitive
understanding of natural systems.
Hongbo completed his Ph.D. in 2014 at Tsinghua University in China. He then went on to several
postdoctoral research positions in the United States before returning to
take the position of assistant professor at Tsinghua
University in 2022. His enthusiastic cooperation with researchers both in China and around the world has helped our
field grow in a substantial way.
—Gary Parker, University of Illinois
Urbana-Champaign
Response
I am truly humbled to receive the Luna B. Leopold Early
Career Award. Leopold’s legacy
in quantitative research
resonates with the values instilled in me by my mentors, who were crucial in my
scientific
development. I thank the letter writers
and the award committee for this honor.
My
journey in science, beginning with a love for physics and mathematics, was
catalyzed by the tragic Wenchuan earthquake of 2008. Right after the disaster,
Guangqian Wang introduced me to work on flood
hazard prediction in the affected
regions, and this experience sparked
my enduring passion
for river dynamics. Xudong
Fu’s mentorship ingrained in me the importance of patience and precision,
qualities that have guided my approach to research. His dedication
to research continues to inspire me to pursue a better version of myself.
At EPFL Swiss Federal
Institute of Technology Lausanne, Christophe Ancey opened my eyes to
the elegance of applying pure mathematics to sediment transport problems. Gary
Parker’s exemplary work in morphodynamics has been a cornerstone of my own research trajectory, showing me how to integrate
fundamental and applied
science.
After
my Ph.D., joining
Jeff Nittrouer’s group
marked a pivotal
phase where I cultivated my fieldwork
abilities and appreciated the indispensable value
of field data.
The challenges of field research
were
mitigated by the inspiration drawn from his stories about
field researchers. This period was also enriched by interactions with
knowledgeable scientists like Gail Kineke, Mike Lamb, David Mohrig, Jim Best, Chris Paola, Marcelo
Garcia, Brandon McElroy, Dan Parsons, Chunhong Hu, and many others. Their
expansive knowledge and sharp insights have greatly broadened my perspective.
I owe a great deal to my close
colleagues, including the late Baosheng Wu, Yuanjian Wang, Yuanfeng Zhang,
Joris Heyman, Marwan Hassan, Tian Dong, Brandee Carlson, Andrew Moodie, Eric
Barefoot, Travis Swanson, Lauren
Simkins, Chenliang Wu, Kyle Strom, Jeffrey Kwang, Gen Li, Matt Czapiga,
Toshiki Iwasaki, Enrica Viparelli, Kieran Dunne, Ajay Limaye, John Shaw, Efi Foufoula-Georgiou, Lawrence
Vulis,
Alex
Tejedor, Ming Tang, and so many others.
Their continuous support,
camaraderie, and countless insightful discussions have been
invaluable.
Reflecting on my first AGU Fall Meeting, in 2012, I recall the engaging and supportive scientific community that continues to motivate my dedication to our
field. Their enthusiasm for discovery bolsters my commitment to the community’s inclusive ethos.
Last,
I wish to express my profound gratitude
to my family. Their unwavering support has been my
constant source of strength and inspiration.
—Hongbo Ma, Department of Hydraulic Engineering, Tsinghua University, Beijing,
China
