A rainfall intensity formula for 100-year return period at Columbus, OH (33-1788) should be developed a by a city water resources engineer. The form of formula was determined as i

= a/(td+12)b where td is a rainfall duration in minutes and i is the rainfall intensity in inches per hour. Obtain the precipitation depth data from NOAA (http://hdsc.nws.noaa.gov/hdsc/pfds/) and use the time range from 5 minutes to 12hours as follows. (2) Based on the data in Column 4 and Column 5, compute the coefficients a and busing a linear regression method. You can plot data manually in the given graph for linear regression or use a software (Excel)as you practiced in lecture. Present your data points and regression line in the graph,and write your linear regression equation clearly. (3) Using the computed a and b, fill out Column 6 (maintain at least two decimal places). [5]