Jeffrey J. McDonnell has been selected as the 2011 Birdsall Dreiss Distinguished Lecturer. The lectureship is made to one person annually by the GSA Hydrogeology Division; McDonnell is the 33rd GSA Birdsall-Dreiss Lecturer and the first from the field of watershed science. Jeff holds the Richardson Chair in Watershed Science at Oregon State University and is OSU Distinguished Professor of Hydrology. He is also 6th Century Chair in Hydrology at University of Aberdeen (UK) and Visiting Professor at the Nanjing Hydraulic Research Institute and Hohai University in China. Jeff is a Fellow of the American Geophysical Union and the International Water Academy. He is recipient of the Dalton Medal from the European Geophysical Union, the Gordon Warwick Award from the British Geomorphological Research Group, the Nystrom Award from the Association of American Geographers and a D.Sc. from the University of Canterbury. Jeff has co-authored ~150 journal articles on watershed hydrology and co-edited the Elsevier textbook “Isotope Tracers in Catchment Hydrology”. He has served as the Senior Advisory Editor of the “Encyclopedia of Hydrological Sciences”, published by John Wiley and Sons and is currently Editor-in-Chief of the IAHS Book Series “Benchmark Papers in Hydrology”. At the request of interested institutions, Jeff will present one of the two lectures summarized below.
A lecture request form is available here.
Where does water go when it rains? Conceptualizing runoff processes in headwater catchments.
Streamflow generation concepts have remained largely unchanged since the First International Hydrological Decade (1965-1974) despite numerous case studies from an ever-widening array of catchments. Two broad classes of streamflow generation behavior have been described and conceptualized into widely used model structures: infiltration excess overland flow and saturation excess overland flow. These concepts rely on the description of spatial patterns of soil surface infiltration rates and “variable source areas” of saturation (from rising near-stream water tables) with known boundary conditions. While subsurface flow during storm events occurs (and in steep wet areas may greatly exceed overland flow contributions), its location and behavior are poorly conceptualized and predicted. The mechanisms of subsurface flow delivery to the stream are seemingly endless and range from lateral preferential flow, to flow along impeding layers, to flow in highly conductive soil and sub-soil layers—all largely unpredictable from conditions at the soil surface. So how can we conceptualize subsurface flow and its many manifestations and such poorly known boundary conditions? Can we simplify the myriad subsurface response mechanisms to be consistent with infiltration excess and saturation excess overland flow concepts? This talk examines the future of runoff conceptualization and advances a simple concept of subsurface “storage excess”. I offer evidence in support of storage excess using field data from catchments distributed across a wide array of climate, geology, vegetation and topographic conditions. These data show subsurface storage filling and then spilling is a simple concept that makes sense across many scales and may help explain runoff amount and timing, geographic and time source components, and residence time. I address how such measures might be used for “gauging” the ungauged catchment as part of the IAHS Decade on Prediction in Ungauged Basins (2003-2012) and informing questions of “what to measure, in what order and why”? This lecture is intended for those interested in water resources, landuse planning, hydrogeology and water quality.
Isotope tracers in catchment hydrology: How far can we go?
The use of stable isotopes as tracers of water has fundamentally changed the way that we view catchment hydrology. Most importantly, isotope tracers have shown that the mean transit time for water through catchments can be orders of magnitude longer than the timescale of hydrologic response. This recognition of prompt delivery of old water to the stream changes the way we consider catchment response to landuse and climate change. Findings from catchment isotope studies have now matured to the point where such information is informing rainfall-runoff model development and testing and new hydrological scaling theory. So how far can we go with isotope tracers in catchment hydrology? This talk explores future avenues of study made possible by the recent development of laser spectrometers—a technology poised to radically alter the field by facilitating increased sample frequencies in time and space and ultimately, routine and widespread field-based deployment. Examples with laser spectrometers are given that show the power of this approach for understanding ecohydrological interactions, rainfall and snowmelt mixing from the plot to hillslope to catchment scale and finally, for addressing transit time distributions and ‘hydrological memory’ of catchments. This lecture is intended for those interested in environmental science, ecohydrology, water resources and water quality.
Background of the Birdsall-Dreiss Lectureship
The Birdsall Lectureship began in 1978, as part of a bequest left to the Geological Society of America – Hydrogeology Division in memory of John Manning Birdsall. Mr. Birdsall was a prominent geologist, retired from the Water Resources Division of the U.S. Geological Survey. He was a scientist, a dedicated public servant and a gentleman. The bequest was used to provide travel funds for outstanding scientists working in the field of hydrogeology to visit other institutions and give talks on their research. The first lecturer, Dr. Jacob Bear from the Israeli Institute of Technology, visited only the University of Wisconsin – Madison, which hosted one of the premier hydrogeology programs of that era. The subsequent list of Birdsall-Dreiss lecturers includes many outstanding scientists from academia and government. The number of institutions visited by each lecturer grew rapidly, with recent lecturers typically giving 40 to 50 talks, mainly in the U.S. and Canada, but also in Europe, Asia and Australia.
One of the most popular Birdsall-Dreiss Lecturers was Dr. Shirley Dreiss from the University of California – Santa Cruz. Shortly after her very successful 1992 lecture tour, Shirley was killed in an auto accident. Her many friends and admirers honored her by contributing to the GSA Birdsall Lectureship, which was renamed the Birdsall-Dreiss Lectureship. The Birdsall-Dreiss Lecturer is chosen each year by a panel of former B-D lecturers. There are no applications for this position and they make their choice solely on the reputation of perspective candidates for their research excellence and ability to communicate.
The Birdsall-Dreiss endowment pays for part of their travel and candidates typically obtain additional travel funds from their home institution. Universities or other institutions wishing to host a Birdsall-Dreiss lecture send in their application in the fall, with the tour officially starting each January and ending at the fall meeting of the Geological Society of America.
Click here to query the Birdsall-Dreiss Lectures Data Base. The data base includes year, lecturer, employer, and abstract title(s).