CIV E 638-SEDIMENTATION AND RIVER ENGINEERING
FALL 2016
FINAL EXAM
WEDNESDAY, DECEMBER 21, 2015, 19:00-21:00

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. 70% questions; 30% essay. Submit your essay in a separate sheet.

  1. To what process did Einstein attribute the drop in sediment transport rate at low discharges (lower regime)?

  2. What are the strength and weaknesses of the Colby 1964 method to calculate discharge of sands?

  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 retention or storage basin, without protecting the downstream channel against degradation?

  5. 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:

    • One (1) reservoir having X volume, or

    • Three (3) reservoirs having X/3 volume each?

  6. In what direction will a bed perturbation in an alluvial channel propagate? Upstream or downstream? Explain.

  7. What is the difference between general scour and local scour? What is the difference between clear-water scour and live-bed scour?