Effective Discharge in Fluvial Geomorphology

Richard Laurence Orndorff, University of Nevada, Las Vegas, Department of Geoscience

Related Links

Initial Publication Date: September 26, 2007

Summary

Use statistically and empirically based solution techniques to calculate the effective discharge of a stream. Students are given a 10-year record of river data on water and bedload discharge, flow frequency, and maximum daily discharge for each year. They must use the data to construct a rating curve for bedload transport, determine total volume of sediment transported by each flow-magnitude class, and discuss the recurrence interval of the effective discharge. Real and fictional data can be used.

Share your modifications and improvements to this activity through the Community Contribution Tool »

Learning Goals

  • Encourage a realistic view of the importance of various flow regimes in sediment transport.
  • Introduce students to the concept of effective flow.

Context for Use

This activity is appropriate for upper-level undergraduate geoscience students and can be adapted for graduate students.

Teaching Notes and Tips

To adapt this exercise to a graduate level class:

  • Compute a cumulative probability curve for streamflow instead of using flow classes.
  • Generate a theoretical lognormal probability-density function for daily streamflow.
  • Develop and compare separate equations for suspended load and bedload.
  • Develop separate transport equations for the rising versus falling limb on a flood hydrograph.
  • Develop unique sediment transport relationships for different climate scenarios.


References and Resources

Activity from:


Stream data can be obtained from several sources including the following:

  • Publications:
    • Kircher, J.E., 1981, Sediment transport and effective discharge of the North Platte, South Platte, and Platte Rivers in Nebraska: U.S. Geological Survey Open File Report 81-53, 26 p.
    • Meade, R.H., Yuzyk, T.R., and Day, T.J., 1990, Movement and storage of sediment in rivers of the United States and Canada, in Wolman, M.G., and Riggs, H.C., editors, Surface Water Hydrology, v. 0-1, The Geology of North America: Boulder, Colorado, Geological Society of America, p. 255-280.
    • Leopold, L.B., 1994, A view of the river: Cambridge, Massachusetts, Harvard University Press, 298 p.
    • Andrews, E.D., and Nankervis, J.M., 1995, Effective discharge and the design of channel maintenance flows for gravel-bed rivers, in Costa, J.E., Miller, A.J., Potter, K.W., and Wilcock, P.R., editors, Natural and anthropogenic influences in fluvial geomorphology: Washington, DC, American Geophysical Union, p. 45-56
    • Schmidt, J.C., and Rubin, D.M., 1995, Regulated stream-flow, fiine-grained deposits, and effective discharge in canyons with abundant debris fans, in costa, J.E., Miller, A.J., Potter, K.W., and Wilcock, P.R., editors, Natural and anthropogenic influences in fluvial geomorphology: Washington, DC, American Geophysical Union, p. 177-195.
    • Leopold, L.B., Wolman, M.G., and Miller, J.P., 1964, Fluvial processes ingeomorphology: San Francisco, California, W.H. Freeman and Company, 522 p. and others, 1964