Question

The runoff  in cumec by the Rational method is defined by ______________

(a) Q = K*A*I*R

(b) Q = (K+A+I) *R

(c) Q = (K+A) *R

(d) Q = A*I*R

The question was posed to me in a job interview.

My question is based upon Rational Method in portion Water Supply for Building, Collection and Conveyance of Sewage, Waste Water Flow Rate of Environmental Engineering

Answer 1

The correct choice is (a) Q = K*A*I*R

The best explanation: According to the Rational method, the storm water or runoff is defined by Q = K*A*I*R where, ‘K’ is a constant, ‘A’ is the catchment area in hectares,’I’ is the impermeability factor and ‘R’ is the intensity of rainfall in mm per hour.