CE444-APPLIED HYDRAULICS
SPRING 2016
FIRST MIDTERM
FEBRUARY 26, 2016, 1500-1550

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. (25%) A 100-acre watershed has two distinct subareas: (1) an undeveloped portion, of 35 ac and runoff coefficient C= 0.3, and (2) a developed portion, of 65 ac and C = 0.7. If the 10-yr rainfall intensity is 0.5 in/hr; what is the peak flow by the rational method? Calculate the exact value (in cfs), using the appropriate unit conversions.

  2. (25%) A rectangular channel is to be designed to convey 100 cfs. The bottom width is b = 10 ft, the bottom slope is So = 0.001, and the Manning's n = 0.013. Calculate the design flow depth (3 significant digits) using trial and error.

  3. (25%) A rectangular channel has a discharge q = 2 m3/s/m. What is the critical depth? What is the critical velocity?

  4. (25%) Please answer questions in a brief statement.

    1. What is the time of concentration? In the most general case (Papadakis formula), what four physical variables is it a function of? Which two variables are in the numerator? Which two are in the denominator?
    2. What is the difference between the Manning and Chezy equations? State three differences.
    3. What four forces are normally present in open-channel hydraulics?
    4. What are the maximum and minimum values of Manning's n that can be achieved in practice?
    5. Is it correct to say that the Chezy coefficient varies with the hydraulics radius, and that the Manning coefficient is a constant?