Implementation - Rainfall Intensity

Rainfall intensity can be specified explicitly or Intensity-Duration-Frequency (I-D-F) curve information and time of concentration Tc can be used.

The relation between the Tc and rainfall intensity is:

   i = K1/(K2+Tc)K3
where:
  i = rainfall intensity in in/hr (mm/hr)
  Tc = Time of concentration in minute.
  K1, K2, K3 = I-D-F curve fitting parameters