CIV E 530- OPEN CHANNEL HYDRAULICS
SPRING 2005
FINAL EXAM
MAY 18, 2005, 1530-1730

Name: ____________________ Red ID _____________________ Grade: ____________

Instructions: Closed book, closed notes. Use engineering paper. When you are finished, staple your work in sequence (1 to 5), and return this sheet with your work.

  1. (20%) A steep rectangular channel with So = 0.015 changes abruptly to another rectangular channel of slope So = 0.004 and of the same width. The friction factor (1/8 of Darcy-Weisbach) in both channels is f= 0.004. The discharge is q = 20 cfs ft-1. What is the length of the resulting C3 profile on the downstream channel?

  2. (20%) A hydraulically wide channel is operating at Froude number F = 0.25. The unit-width discharge is q = 3 m2s-1. What is Lagrange's relative celerity? What are two Langrange absolute celerities (usptream and downstream)?

  3. (20%) You are observing the rising flood stage of a major river. At your observation point, at a certain time the discharge is 300 m3 s-1, and the stage is rising at the rate of 8 mm hr-1. The surface width of the river at this point, and for several kilometers upstream, is 105 m. What is your quick estimate of the present discharge at a point located 10 km upstream of your observation point?

  4. (20%) Please answer each question in one clear and concise paragraph:

    • What is the rationale for the labyrinth spillway? When does it cease to work as intended?

    • Compare kinematic, diffusion, and dynamic waves in terms of their celerities and diffusivities.

    • At what Froude and Vedernikov numbers do kinematic, diffusion and dynamic wave coalesce?

    • What is the difference between the Schaake and Li methods to solve the kinematic wave equation? Which method is more stable? Which method is more accurate?

  5. (20%) Write a 300-word essay either (a) defending or (b) attacking the Muskingum-Cunge method. Please consider content, grammar, and spelling.