The Impact of Recession Infiltration on Runoff Volume Computed by the Kinematic Wave Model

This is the authors' abstract. We don't add key points for this paper.

The effect of recession infiltration on runoff volume is quantified using the kinematic wave model for the case of lateral inflow made up of constant rainfall excess during the period of rainfall and constant infiltration after rainfall ends. A general solution is obtained using the following non-dimensional quantities; Q* = Q/Re (runoff volume divided by rainfall excess volume), t* = te/D (time to kinematic equilibrium divided by the duration of rainfall excess), and f* = f/re (infiltration rate divided by rainfall excess rate). Using these quantities, the relationship for the reduction of runoff volume is Q* = 1 m/(m+1) t* [f*/(f*+1)]1/m when t* < [(f*+1)/f*]1/m and Q* = 1/(m+1) t*m (f*+1)/f* when t* = [(f*+1)/f*]1/m where m is the kinematic wave depth-discharge exponent. The first equation corresponds to the case when flow ceases after the characteristic from distance and time zero, C(0,0), reaches the end of the plane. The second equation corresponds to the case when the flow ceases and C(0,0) does not reach the end of the plane. These equations approximate the reduction of runoff volume for the more general case of time varying rainfall excess under constant and variable rainfall as would be the case when the rainfall excess is generated using the Green-Ampt infiltration equation.