CIV E 638-SEDIMENTATION AND RIVER ENGINEERING
SPRING 2015
FINAL EXAM, THURSDAY, MAY 14, 2015

Name: ______________ Red ID: _____________ Grade: _______

Instructions: Closed book, turn off cellphone. 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 drop in sediment transport rate at low discharges (lower regime)?

  3. Should the Salton Basin have been developed? Or not?

  4. How does time engineering differ from frequency-based hydraulic design?

  5. 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?

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

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

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

  9. 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?

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

  11. Why is a grab sediment sample not representative of the average sediment concentration?