CIV E 445-APPLIED HYDROLOGY
SPRING 2014
SECOND MIDTERM
APRIL 8, 2014, 1400-1450

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. (50%) A certain basin has the following 2-hr unit hydrograph (1 cm of rainfall), defined at hourly ordinates:

    Cumulative time (hr)0 1 2 3 4 5 6 7 8 9 10 11 12 0
    Flow (m3/s)0 5 15 30 60 70 60 55 45 35 25 15 5 0

    Calculate the composite flood hydrograph for the following effective storm pattern:

    Time (hr) 0-33-6
    Effective rainfall (cm/hr)24
    Effective rainfall (cm)612

  2. (50%) Please answer in a brief statement:

    1. What is the upper size limit (in square miles) for a small catchment?
    2. Who is credited with developing the 100-yr flood as the applicable design flood for the U.S.?
    3. What is the exponent of the rating (β) under turbulent Manning flow in overland flow?
    4. What bottom slope assures that the wave is kinematic in overland flow?
    5. What are the four explicit variables (or parameters) in the runoff curve number methodology?
    6. What is the standard peak rate factor (PRF) in the NRCS synthetic unit hydrograph methodology?
    7. Who is credited with developing the unit hydrograph? What scale of basin was he using?
    8. Which NRCS type storm (I, IA, II, or III) is the most intense? Where is it applicable?
    9. According to Gumbel, what is the return period of the mean annual flood?
    10. If an x-y paired data set describes a perfect circle when plotted, what is the correlation coefficient?