Short Course on River Dynamics and Vegetation in the Arid West
The topic of this short course is River Dynamics and Vegetation in the Arid West.
The course includes lectures on a case-study of the Rio Puerco, New Mexico, on the theory of river water and sediment transport. Two hands-on components include sandbox experiments and spreadsheets and numerical modeling experiments.
This material was developed by CU researchers, Greg Tucker, Irina Overeem and Mariela Perignon and is geared toward secondary science teachers, with application to curriculum in earth science, physics and biology.
Material can be used with grades 6-8, as well as more in in-depth with grades 9-12.
Material can be applicable to topics in general science courses at undergraduate level.
We share insights on river processes in the Western US. Lectures highlight the basic terminology and physics of water flow and sedimentation processes. The short course uses the Rio Puerco, New Mexico, to illustrate how river morphology can rapidly change, and looks at impacts of the introduction of the invasive tree species Tamarisk in the 1920s. At the turn of the 20th century the relatively small Rio Puerco delivered large amounts of sediment to the Rio Grande in New Mexico and threatened to rapidly decrease the lifetime of Elephant Butte Reservoir. Elephant Butte Reservoir provides New Mexico and Texas with critical storage of Rio Grande water for agricultural use. Scientist and engineers at the time proposed vegetation measures to manage the rapid erosion in the Rio Puerco channel and thus reduce the sediment load being drained into the Rio Grande. More recently, invasive species have been recognized as a threat to the natural floodplain ecosystem in the West. Large floods occurred in 2006 and again in 2013 (coincident with the floods in the Front Range of Colorado). Efforts to destroy Tamarisk have led again to dramatic changes in channel geometry and sedimentation during these floods. Thus, the Rio Puerco represents a unique natural experiment in the effects of long-term vegetation change on a dryland river system.
The material has notes on sandbox experiments and computer modeling that can be easily used in your own classrooms to learn about river dynamics and vegetation.
A course description is posted here: Syllabus for River Dynamics and Vegetation
- Lecture 1 The Rio Puerco, New Mexico; a story of changing river morphology and invasive species by Mariela Perignon [download (50MB) | download (15MB)]
- Lecture 2 Theory of River Flow and Sedimentation Processes by Greg Tucker [download]
- Discussion Notes on Invasive Species by Irina Overeem [download]
- Lecture 3 Rivers and Vegetation in the Arid US West by Irina Overeem [download]
Sandbox flumes can be easily built from repurposed and inexpensive materials to simulate the behavior of rivers like the Rio Puerco and explore the role of floods and vegetation on the shape of the channel.
Download instructions and worksheets for setting up sandbox experiments for your own class
Explore conceptual hydrographs for overland flow using the Manning's equation overland flow calculations with Vlab
More theory is explained in the aassociated textbook chapter: http://onlinecalc.sdsu.edu/enghydro/engineering_hydrology_04.php#overland Realistic values for Manning coefficients
Scientific papers on the Rio Puerco and vegetation
- Perignon, M. C., G. E. Tucker, E. R. Griffin, and J. M. Friedman (2013), Effects of riparian vegetation on topographic change during a large flood event, Rio Puerco, New Mexico, USA, J. Geophys. Res. Earth Surf., 118, 1193–1209, doi:10.1002/jgrf.20073.
- Griffin, E.R., Kean, J.,W., Vincent, K.R., Smith, J.D., Friedman, J.M., 2005. Modeling effects of bank friction and woddy bank vegetation on channel flow and boundary shear stress in teh Rio Puerco, New Mexico. Journal of Geophysical Research, 110, F4,, doi:10.1029/2005JF000322.
Popular science and great additional information:
- A New York Times article on drought in the Rio Grande River Basin
- Reisner, M., 1993. Cadillac Desert: The American West and Its Disappearing Water. Penguin, ISBN 0140178244, 9780140178241, 582p.
Movies and Model Simulations
More general movies relevant to the river processes discussed:
- Look at sediment transport with a flashflood
- Elephant Butte Dam was just one of 100's of dams and reservoirs built over the last 200 years in the US
- the expansion of dams and reservoirs worldwide
Movies and model simulations specific for the recent floods in the Rio Puerco:
- See how high the Rio Puerco flooded in 2013
- Community downstream experienced damage due to flooding of the Rio Puerco 2013
- The floodwater spilled over from the Rio Puerco arroyo