The 2012 John Dalton Medal is awarded to Kurt Roth for his extraordinary creativity and pioneering contributions to flow and transport processes in the vadose zone, and its interactions with the saturated zone and with the atmosphere.
Kurt Roth is an eminent soil hydrologist of extraordinary creativity. He has been brilliant in his theoretical and experimental work dealing with flow and transport processes in the vadose zone, and its interactions with the saturated zone and the atmosphere. His studies have covered such diverse topics as contaminant transport in the vadose zone, deterministic and probabilistic modeling of field-scale transport, invasive and non-invasive geophysical instrumentation, scale issues in soil hydrology, and the hydrology of permafrost. Roth’s key contributions to vadose zone hydrology include trailblazing theoretical and experimental work on stochastic solute transport models. Especially noteworthy is the concept of transfer function modeling developed jointly with Bill Jury (and presented in their highly cited book), which is rated as amongst the most useful tools emerging from contemporary stochastic hydrology. Roth has introduced novel ways to parameterize soil structure, in the form of the unique “scaleway” approach that combines both averaging and explicit representation of structure. This, for the first time in soil physics, allowed the effects of small-scale structures to be parameterized at a given scale while larger ones are explicitly resolved. This well‐reasoned and engaging treatment of scaling of porous media properties and flow regimes has already become a classic. Roth has also provided both experimental and theoretical tools needed to cope with the real nature of soils. His thorough understanding of physics and mathematics, and background in electronics, has made it possible for him to model electromagnetic wave propagation through heterogeneous soils. This knowledge was crucial for using ground-penetrating radar (GPR) and for interpreting the time domain reflectometry (TDR) signal to measure water contents in the field, and has opened the door for both small- and large-scale investigations of soil water content. Roth’s recent activities in permafrost studies in China, including the GPR characterization of permafrost dynamics, are a clear example of his mode of (co)-operation. Being an imaginative and well trained experimentalist, he actively participates in field campaigns and knows what data mean to a modeller. His ability to collaborate with hydrologists, soil scientists, biologists, and physicists, has opened new perspectives and research avenues and led to better linkages between these research fields. Indeed, he is one of the few soil hydrologists embedded in a leading physics department, and in this way he has helped bridge the separation between “basic” and “applied” sciences. Besides his outstanding research contributions, Roth has placed emphasis on high-quality teaching and student education. Many of his students have moved on to successful faculty and research careers at prestigious institutions. Through his lectures and university mentoring, Roth has shared and propagated his exemplary understanding of the physics of hydrological systems with many generations of young scientists. Professor Roth’s scientifically rigorous and efficient style of working and his critical but constructive support has made him a well-respected associate editor of Water Resources Research (American Geophysical Union) and PEDOSPHERE (Chinese Academy Sciences) journals. Most notably, he has served as an executive editor of the HESS journal (European Geosciences Union) in the pioneering phase of open access publishing, helping to put HESS on a firm footing. Roth will continue to make a significant contribution to soil hydrology research through his creativity, insights and experience, and through his attitude to service to both science and the community he will continue to provide a guiding hand to a yet new generation of soil hydrologists in the future. It is for these reasons that Roth is awarded the John Dalton Medal of the European Geosciences Union. He is an inspiration to us all.