The following questions refer to Fig. the IDF curve for Houston, Texas.
(a) What is the return period of a storm that recorded 3.1 in./hr for 2 hr in Houston?
(b) What amount of rain (in.) would have to fall in a 6-hr period to be considered a 100-yr storm in Houston?
(c) What is the return period of a storm that lasts 1 hr and records 3.5 in. of rainfall?
(d) Develop and plot a 6-hr, 100-yr storm design rainfall using 1-hr time steps (see Fig.1¬8). Assume the maximum hourly value occurs between hours 3 and 4.
(i) Find the rainfall intensity for a 1-hr duration and plot the rainfall intensity in in./hr between the hours of 3 and 4 on a bar graph.
(ii) Then, find the rainfall intensity for a 2-hr duration; multiply the intensity by the duration of rain to get the volume. Plot the difference between the 2-hr duration volume and the 1-hr duration volume for hours 2 to 3 on a bar graph.
(iii) Continue in the same way for the 3-hr duration, plotting the new intensity to the right of the maximum (hour between 4-5). (Find the 3-hr volume and subtract the 2-hr volume.)
(iv) Then, find the rainfall intensity for a 6-hr duration and the respective volume. Plot the remaining volume (6-hr minus 3-hr) over the 3 hours, assuming equal distribution between them, with two bars to the left and one to the right of the maximum (time intervals 0-1, 1-2, and 5-6).