CIV E 445-APPLIED HYDROLOGY
SPRING 2009
FIRST MIDTERM
MONDAY, MARCH 2, 2009, 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 195-km2 basin has 700 mm of mean annual precipitation, and the mean annual outflow is 2.5 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
    2 1
    infinity0.5

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

    1. What four types of mathematical models are used in hydrology?
    2. What four processes are responsible for the cooling of air masses which leads to precipitation?
    3. What is the return period used for regional flood protection works?
    4. What is the Bowen ratio?
    5. What is albedo? What is the albedo of the Amazon rainforest? What is the albedo of the Sahara desert?
    6. What is the difference between potential and actual evapotranspiration?
    7. What four factors is the time of concentration a function of?
    8. How does time of concentration vary with flood stage? Draw a sketch for a wide range of flood stages.
    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? List them in order of occurrence.