Instructions: Closed book, closed notes. Use engineering paper. When you are finished, staple your work in sequence (1 to 3), and return this sheet with your work.

1. (25%) What is the discharge in a rectangular channel of bottom width b = 5 m, bed slope S_o = 0.003, Manning's n= 0.015, and flow depth y = 1.5 m?

2. (25%) A weir is located at the downstream end of a wide rectangular channel of bottom slope S_o = 0.004 and (dimensionless Chezy) friction factor f = 0.004. The unit-width discharge in the wide rectangular channel is 2 m³/s/m. Immediately upstream of the weir, the flow is subcritical, with depth 3 m.
   1. Calculate the upstream Froude number.
      

   2. Calculate the upstream flow depth.
      

   3. Calculate the usptream flow velocity.
      

   4. What is the type of water-surface profile?
      

   5. Calculate the length of the water-surface profile.
      

3. (25%) Please answer the following questions in a brief statement.

   1. Who was Manning?

   2. What is "hungry water"?

   3. How many types of water surface profiles (WSP) are there in gradually varied flow (GVF)? Which water surface profiles are completely horizontal?

   4. In gradually varied flow in a hydraulically wide channel, the flow depth gradient S_y is a function of three (geometric and physical) parameters. What are these?

   5. What are the five characteristic values to which the flow depth gradient S_y tends in WSP computations?
      

4. (25%) Do a tabular comparison between the direct-step and standard-step methods of steady gradually varied flow computation. State at least eight differences.