2023-2024: Earth and Planetary Surface Processes: Jim Best

Jim Best
University of Illinois at Urbana-Champaign

Biography

Jim Best holds the Jack and Richard Threet Chair in Sedimentary Geology in the Department of Earth Science and Environmental Change at the University of Illinois at Urbana-Champaign, where he is also Professor of Physical Geography and holds affiliate positions in Mechanical Science and Engineering, Civil and Environmental Engineering and the Center for Latin American and Caribbean Studies. He gained his BSc Combined Honors degree in Geology and Geography from the University of Leeds, UK, and his PhD from Birkbeck College, University of London. He was then appointed as a Lecturer in Geology, University of Hull, before moving to the University of Leeds, where he held positions as Lecturer in Earth Sciences, Reader in Experimental Sedimentology, and Chair in Process Sedimentology. He moved to the University of Illinois at Urbana-Champaign in 2006.

Jim’s research interests center around understanding the physical processes of sedimentation and their products in both contemporary and ancient sedimentary environments. His research has included investigating the interactions between fluid mechanics, sediment transport and bedform development; turbulence modulation in sedimentological flows; the fluid dynamics of porous sediment surfaces; bedform dynamics; alluvial channel dynamics and deposits; the morphodynamics of river channel confluences; the sedimentology and geomorphology of large rivers; the physical scale modelling of braided rivers; development of fluid dynamic techniques for experimental sedimentology;  turbidity current dynamics and deposits in modern and ancient lacustrine and deep-sea basins; the sedimentology of deltas; and the application of multibeam imaging within sedimentary environments.

He was elected a fellow of the AGU in 2015, and in 2018 was awarded the Jean Baptiste Lamarck Medal by the European Geosciences Union for his ‘major contributions to our understanding of physical sedimentary processes and their products in the geological record’. He has held research fellowships from the Royal Society of London and Leverhulme Trust, and has conducted field work in many countries, including Argentina, Bangladesh, Brazil, Cambodia, Canada, Chile, China, Eire, England, New Zealand and the USA. Relevant to this Distinguished Lecture Series, he has conducted field research on the Jamuna, Meghna, Amazon, Mekong, Huang He and Mississippi rivers. A focus of his research over the past twenty years has been the geomorphology and sedimentology of large rivers and the influence of anthropogenic stresses, including the impacts of damming, sediment mining and sedimentation.

Abstract: The Future of the World’s Great Rivers: Anthropogenic Stresses, Impacts and Possible Solutions

The world’s rivers have been, and remain, integral to the evolution and functioning of human societies, and host a magnificent ecodiversity that provides huge natural capital. When you stand near the mouth of a great river and gaze upon its channel, the flow of water and sediment that passes by you tells not only of the processes and evolution of the upstream landscape, but also of the history of its flora, fauna and human occupants. These rivers give us an insight into past landscapes, ecosystems and human history. As such, rivers are rooted in the human soul.

But with increasing populations and economic development, come increasing stresses on these vital waterways. In some cases, these stresses have been operative for hundreds, if not thousands, of years – for example, land-use change. In other rivers, these stresses are relatively recent but may impart virtually instantaneous impacts, such as dam construction. The world’s large rivers are now under pressure from a wide range of anthropogenic stressors, including water regulation, pollution, sediment mining, climate change, non-native species, pollution, and land-use change. Such changes may affect both the flow of water and sediment, and thus the geomorphology of the rivers: in some cases, humans are essentially redrawing the geography of river catchments.

This talk will review the wide range of anthropogenic stresses that are affecting the world’s large rivers and discuss their impact upon the physical and human landscapes on which they are situated. Using examples from several large rivers, the talk will examine some of the principal stressors, and both the spatial and temporal scales of their effects. These considerations suggest the necessity for ‘environmental triage’ to identify which stressors are most important to combat and over which timescales, and if multiple stressors must be tackled due to their interactions. Solutions that can be considered to help mitigate or ameliorate some of these stressors will be discussed, including the central need to place these in the context of those who rely on rivers for their livelihoods and helping improve their quality of life. A deeper trans-disciplinary appreciation of riverine landscapes and their human occupants, and the need to better monitor and assess their socio-ecogeomorphology, lie at the heart of their sustainable management. The talk will highlight the many roles and responsibilities that Earth scientists are spearheading in this grand challenge, and the revolutionary new ways by which we are able to measure and monitor the dynamics of large rivers.