CIV E 445-APPLIED HYDROLOGY
SPRING 2008
FIRST MIDTERM
MONDAY, FEBRUARY 25, 2008, 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 3), and return this sheet with your work.

  1. (25%) A 250-km2 basin has 800 mm of mean annual precipitation, and the mean annual outflow is 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:

    Time (hr) f (mm/hr)
    1 2.75
    2 1.85
    infinity 1.40

  3. (50%) Please answer questions in a brief statement.

    1. What is the difference between hydraulics and hydrology? Be specific.
    2. What types of mathematical models are used in hydrology?
    3. What is the difference between potential and actual evapotranspiration? Which one can be calculated with existing formulas?
    4. What four factors affect time of concentration?
    5. What is baseflow? Where does it come from? How can baseflow be lost?
    6. What is the range of bottom (river, creek) slopes likely to be encountered in practical hydrologic applications?
    7. Under what circumstances can recorded hydrologic data (precipitation, discharge) become obsolete?
    8. What is a rating curve? When is a rating unique? When is a rating nonunique or looped?
    9. What do the Creager curves depict?
    10. To what five factors is to be attributed the recurrence of debris flows in the San Gabriel Mountains of Northeast Los Angeles? State them in causal order.