CIV E 445-APPLIED HYDROLOGY
SPRING 2010
FIRST MIDTERM
WEDNESDAY, MARCH 3, 2010, 0730-0845

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. (25%) A 185-km2 basin has 625 mm of mean annual precipitation, and the mean annual outflow is 1.2 m3 s-1. What percentage of precipitation is abstracted by the catchment on a mean annual basis?

  2. (25%) Fit a Horton infiltration formula to the following measurements:

    f = fc + ( fo - fc ) e -kt

    Time
    (hr)     		f
    (mm/hr)
    1 2.5
    2 1.5
    infinity0.7

  3. (30%) Please answer questions in a brief statement.

    • What is the Bowen ratio?
    • What is albedo? What is the albedo of the Amazon rainforest? What is the albedo of the Sahara desert?
    • What is the difference between potential and actual evapotranspiration?
    • How does time of concentration vary with flood stage? Draw a sketch for a wide range of flood stages.
    • What do the Creager curves depict?
    • To what five factors is to be attributed the recurrence of debris flows in the San Gabriel Mountains of Northeast Los Angeles? List them in order of occurrence.

  4. (20%) Write a 200-word essay on why the rational method should not be applied to midsize and large basins. Pay specific attention to technical accuracy, grammar, and style. Be as complete and thorough as possible.