Ponding Analysis with Green-and-Ampt Infiltration

The ponding of water over level terrain caused by storms of arbitrary temporal intensity is quantified by solving water-balance differential equations involving cumulative rainfall, infiltration, the depth of ponded water, and evaporation of ponded water. Infiltration is quantified using an extended Green-and-Ampt formulation in which the depth of ponded water influences the infiltration rate. A numerical algorithm for calculating the infiltration and ponding hydrographs is developed and applied in this work. The maximum depth of ponded water and the duration of ponding are among the variables that can be calculated with the method presented in this paper. These variables are useful in basin irrigation and in wetland wetting and restoration.