Question

Water from a 100 ft x 200 ft lawn converges into a gully. During a 1-hour storm, discharge into the gully is 0.37 cfs (ft3/s). The interception by grass is 0.02 acre-ft. Overall, 70% of the rain is infiltrated. What is the amount of rainfall?

Answer 1

7344 ft^3

Step-by-step explanation:

rain flown = 0.37 ft^3/s * 3600 s/hr = 1332 ft^3

rain intercepted by grass = 0.02 acre-ft = 0.02 * 43559.9 = 871.2 ft^3

AS 1 acre-ft = 43559.9 ft^3

LET THE TOTAL RAINFALL BE 'X'

Thus the equations become

x = 0.7x + 871.2 +1332 (as 70 % of rain in infiltrated)

x = 7344 ft^3