CIV E 638-SEDIMENTATION AND RIVER ENGINEERING
FALL 2012
FINAL EXAM, WEDNESDAY, DECEMBER 12, 2012

Name: ___________________ Red ID: _________________ Grade: _______

Instructions: Closed book, closed notes. Answer only ten (10) questions. Use engineering paper. When you are finished, staple your work in sequence, and return this sheet with your work.

Answer only ten (10) questions.

  1. Of what variable is the Brune [sediment] trap efficiency of a reservoir primarily a function of? All other variables [factors] being equal, which reservoir system will fill up faster: (1) one reservoir having X volume, or (2) two reservoirs having X/2 volume each?

  2. To what process did Einstein attribute the cause of meandering?

  3. What is the difference between the original Lane relation and the modified Lane relation? What is the value of the exponent m that would render the sediment transport relation [unit-width sediment discharge vs mean velocity] dimensionless?

  4. Why is it a fallacy to retain sediment in a planned basin, without protecting the downstream channel against degradation?

  5. A bed perturbation in an alluvial channel will propagate upstream or downstream? Explain.

  6. State the basic elements of Leopold's hydraulic geometry of stream channels.

  7. What is hungry water? How can it be explained on the basis of theory?

  8. According to Lane, the equilibrium shape [aspect ratio To/Yo] of self-formed channel in noncohesive alluvium is a function of two variables. What are these variables?

  9. What is the difference between general and local scour?

  10. What is the difference between contraction scour and local scour?

  11. Why is the celerity of bed perturbations important in numerical modeling of sediment transients?

  12. Which is the only sediment transport method that computes total load, including wash load and unmeasured load?
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