Geosciences and Environmental Science Colloquium Series

The Kimbell School of Geosciences hosts an exciting series of presentations open to the entire campus community.  The geosciences and environmental science colloquium series brings experts to our campus to present their research to our students and members of a broad audience. In addition to Thursday afternoon presentations, roughly one per month, the speakers interact with students and faculty.

5:15 PM          Tuesday, May 1, 2018           Bolin Science Hall 127

Dr. Peyton E. Lisenby, Research Associate, Macquarie University                                                                                                     
Big Ideas in Fluvial Geomorphology: Using Big Concepts to Guide our Understanding of River Environments


The aims of geomorphic research have historically tended to focus on characterizing progressively smaller-scaled mechanisms to explain the inner workings of the natural processes that shape landforms. These ‘reductionist’ approaches have significantly improved our understanding of geomorphic processes in a variety of environments. However, they sometimes fail to account for the influences of larger-scaled factors that can control small-scaled mechanisms. The development of the concept of geomorphic effectiveness provides an excellent example of how ‘big-picture’ approaches are necessary to capture the complexity of geomorphic systems. Herein, I present an analysis of river behavior where I use the development of the ‘geomorphic effectiveness’ concept to identify and characterize controls on the ability of rivers to respond to flood events through the adjustment of fluvial landforms. These controls are embodied by the concepts of river sensitivity and sediment connectivity. The sensitivity of river channels to geomorphic adjustment and the dynamics of sediment connectivity along channel networks are key controls on geomorphic response. In turn, the cumulative impact of geomorphic responses to successive floods determines the geomorphic effectiveness of any flood event. For managers, analyses of river sensitivity and sediment connectivity can be incorporated into the decision-making process regarding where to prioritize management actions as part of catchment action planning that works with, not against, the natural behavior of riverine environments. Moreover, the science of geomorphology is well placed to fill the gaps in our understanding of the linkages between physical landform structure and biological function, providing an essential role in environmental science research and education.


Past Semesters (pdf)