The infiltration capacity of a soil follows the Horton’s exponential model,
f = 13 + 29 e-(3/2)t
where f is in mm/hr and t is the time in hour. The total depth of infiltration and average infiltration rate during the first 40 min of a storm respectively is
1
1.55 mm and 2.33 mm/hr
2
23.66 mm and 35.5 mm/hr
3
13 mm and 19.5 mm/hr
4
20.89 mm and 31.33 mm/hr