CIV E 445 - APPLIED HYDROLOGY
SPRING 2014
HOMEWORK No. 2

  1. Given the following intensity-duration data, find the constants a and b of Eq. 2-6 of the text.

    Intensity (mm/h) 45 20
    Duration (h) 1 2

  2. Fit a Horton infiltration formula to the following measurements:

    Time (h) f (mm/h)
    1 3.5
    3 1
    ∞ 0.6

  3. The following rainfall distribution was measured during a 12-h storm:

    Time (h) 0-2 2-4 4-6 6-8 8-10 10-12
    Rainfall Intensity (cm/h) 1.0 2.0 3.0 4.0 2.0 1.0

    Runoff depth was 12 cm. Calculate the φ-index for this storm.

  4. Use the Meyer equation (Eq. 2-28a in the text) to calculate monthly evaporation for a large lake, given the following data: Month of July; mean monthly air temperature: 70°F; mean monthly relative humidity: 60%; mean monthly wind speed at 25-ft height: 20 mph.