CIV E 530- OPEN CHANNEL HYDRAULICS
SPRING 2008
FINAL EXAM
MONDAY, DECEMBER 15, 2008, 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 4), and return this sheet with your work.

  1. (20%) A hydraulically wide channel is operating at Froude number F = 0.3. The unit-width discharge is q = 2.0 m2s-1. What is Lagrange's relative celerity? What are two Langrange absolute celerities (upstream and downstream)?

  2. (20%) You are observing the rising flood stage of a major river. At your observation point, at a certain time the discharge is 495 m3 s-1, and the stage is rising at the rate of 5 mm hr-1. At a point located 18 km upstream of your observation point, the stage is rising at the rate of 7 mm hr-1. The surface width of the river in the study reach is 125 m. What is your estimate of the present discharge at the upstream end of the reach?

  3. (40%) Please answer each question in one clear and concise paragraph:

    • What is the rationale for the use of a labyrinth spillway?

    • Compare in tabular form the kinematic, diffusion, dynamic, and inertia-pressure waves in terms of their celerity and attenuation properties.

    • What are three ways in which the Seddon formula can be expressed?

    • Under what conditions is a wave likely to be dynamic? Give an example in practice.

    • What is the difference between sediment production and sediment yield?

    • What is the difference between sediment transport and sediment routing?

    • Why is sediment production not relevant to the calculation of sediment transport?

    • What is the only sediment transport method that considers all modes of transport, by size fractions, measured and unmeasured?

  4. (20%) Write a 200-word essay on HEC-RAS. Separate into four paragraphs (5 points each): (1) history, (2) objectives, (3) equation and solution, and (4) data requirements.