CIV E 638-SEDIMENTATION AND RIVER ENGINEERING
SPRING 2015
MIDTERM EXAM, MONDAY, MARCH 12, 2015

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. What does the Shields curve express? What are the parameters (x and y)? What is the accepted threshold value of the Shields parameter for initiation of motion?

  2. What is the value of Froude number that guarantees initiation of motion under most conditions of practical interest?

  3. List the five friction descriptors used in sedimentation and river engineering.

  4. What is Jarrett's contribution to river mechanics?

  5. How is critical shear stress related to critical velocity?

  6. According to Humboldt, how are forests, floods and springs related?

  7. How does Nature minimize the changes in stage with changes in discharge? Explain.

  8. What is the difference between sediment production, sediment yield, sediment transport, and sediment routing?

  9. What are the modes or types of sediment transport in alluvial channels? Describe the various types with the aid of a table.

  10. What is Colby's contribution to sedimentation engineering?

  11. Bonus question (may replace any of the above) What is the range of variation of the exponent of the unit-width solid discharge/mean velocity relation? Explain how this exponent is affected by the bed configuration. What did Einstein say on the subject?