Keith Beven

2012 Robert E. Horton Medal Winner


Keith Beven was awarded the 2012 Robert E. Horton Medal at the AGU Fall Meeting Honors Ceremony, held on 5 December 2012 in San Francisco, Calif. The medal is for “outstanding contributions to hydrology.”



It is a pleasure to introduce Keith Beven, currently Distinguished Professor at Lancaster University UK and visiting Professor at Uppsala University, Sweden and EPFL, Lausanne, Switzerland, as the recipient of the 2012 Robert Horton Medal. Keith’s contributions to the geophysical aspects of hydrology are unusually rich. Keith is the world’s most cited hydrologist and continues to be the thought leader in the area of rainfall-runoff processes, hydrological modeling, and uncertain estimation techniques. As an experimentalist, Keith has made substantial contributions to soil physics and our understanding of preferential flow. His early work linking preferential flow and kinematic wave approaches forms the foundations of the field. As a modeler, Keith’s TOPMODEL concept (developed with Mike Kirkby) ushered in a new approach to catchment modeling, one driven by terrain information and process-based assumptions of how water is routed to the stream. TOPMODEL components, like the topographic index and the concept of hydrological similarity have influenced many fields outside of hydrology, including geomorphology, ecology, geotechnical engineering, and atmospheric science. Keith has done more than any other hydrologist to show that estimation of uncertainty is an integral part of environmental modeling. The concepts that he has introduced, such as equifinality and uniqueness of place, have helped define current practice. The tools that he has developed, like the Generalized Likelihood Estimation Technique (GLUE), have helped operationalize the regular use of uncertainty techniques. For these contributions, Keith has been an AGU Fellow since 1995 and has been awarded the Dalton Medal from the European Geophysical Union, the Hydrology Section Award, and the IAHS/WMO/UNESCO International Hydrology Award.


Keith has been a keen student of hydrological history, compiling the first IAHS Benchmark Papers in Hydrology volume on Streamflow Generation Processes. In that work, he showed remarkable sense of the evolution of the discipline, reverence for the main contributors to the science, and guidance for the would-be student to find her or his path through the literature. Keith has also been a student of Horton. Keith’s AGU Langbein Lecture in 2004 was titled “Robert Horton and the application of distributed hydrological models.” He, more than any other hydrologist since the late Walter Langbein, has honored the Horton legacy. His hydrological sleuthing revealed many hitherto unpublished contributions to the field by Horton; including new insights into how Horton viewed the infiltration process and groundwater dynamics.


Despite all his accolades and honors he has received, he is a most humble and unselfish giver of time. He collaborates extensively with junior and senior colleagues across the world, and has provided a large and distinguished set of students and coworkers with inspiration and insight. He has twice been awarded the AGU Commendation for Excellence in Refereeing. This speaks volumes for the character of the man and the way he impacts the field unselfishly through his actions.


In short, Keith Beven is an outstanding scientist and person, and a truly worthy and highly appropriate recipient of this year’s medal.


Jeff McDonnell, University of Saskatchewan, Saskatoon, Saskatchewan, Canada



I am extremely grateful to Jeff McDonnell for having led this nomination and for his very generous citation.   I am also, of course, deeply honored by this award, particularly since I have the greatest respect for Robert Horton as perhaps the most important hydrologist of the 20th century.  Certainly as far as I know, he is the only hydrologist to have a waterfall named after him, near his home in Voorheesville, New York.   That respect was deepened when a few years ago I had the opportunity to look over just a small selection of the 94 boxes of his papers in the National Archives.  That showed that he had a much greater appreciation of the complexity of hydrological systems than he is given credit for in current text books.   It is that complexity that I have struggled with throughout my career, complexity that is so poorly represented by the available measurement techniques and which makes hydrological prediction so difficult and shot through with epistemic uncertainties, i.e., uncertainties that arise from lack of knowledge rather than random natural variability. The GLUE methodology was mentioned in the citation. It is an on-going research program that tries to deal with uncertainty in nonideal real-world applications when simple statistical assumptions may not be enough. 


By definition, of course, epistemic uncertainties pose impossible problems to the modeler.   If we had adequate knowledge to represent them, they would not be epistemic.   But research still thrives on the challenge of impossible problems and I still feel very much like a student trying to understand the problems before I will be satisfied.


No one ever receives an honor like this without being in debt to many people, both teachers and students.  In maintaining a student-like approach to research I have been fortunate to have had some rather good mentors, particularly Mike Kirkby, George Hornberger, and Peter Young, all still remarkably active in their own research.   I have also worked with people such as Andy Binley, Sarka Blazkova, Jim Freer, Peter Germann, Rob Lamb, Eric Wood, Jeff himself and many others who have contributed hugely to my own development as a student of hydrology and hydrological modeling.


During a lot of my career I have often been somewhat at odds with mainstream hydrological research.   Many of my citations have therefore come from papers trying to explain why I have been wrong, or overly subjective, or undermining the science.   I will happily admit to often playing the devil’s advocate in trying to persuade others to be more circumspect in modeling these difficult systems.  But there is a serious issue at the heart of these debates. As Jay Famiglietti put it so nicely recently, how can we manage water for the benefit of mankind in nonstationary times when we know so little about its various stores, flow pathways, and residence times even in a developed country like the United States?   Should these epistemic uncertainties and their effects on model predictions have an effect on our management strategies and decision making?  It is all too easy to provide predictions to decision makers these days that are not underpinned by rigorous or adequate science.   For example, how should we address the hydrological impacts of climate change on water when predictions of precipitation under current climate are so poor in many parts of the world?  How can we be confident about the impact of fracking on water quality in the long term when so much knowledge is lacking?   We do know that contamination is one of the greatest factors affecting the available water resource and that once water sources are contaminated they can be hugely difficult and enormously expensive to clean up.  In many places it is already too late.   How then can we reflect and react to such epistemic uncertainties?  The question is urgent in both hydrology and other environmental sciences.   It is a question that Robert Horton would be contributing to if he were alive today.  I still hope to throw more light on this before I am done.


Keith Beven,Lancaster University, Uppsala University and EPFL, Lausanne