GREEN AND AMPT INFILTRATION WITH REDISTRIBUTION

Distributed, physically based watershed and irrigation advance models require robust infiltration estimation capabilities. The empirical Gre en and Ampt (GA) equation of infiltration is a popular method for esti mating infiltration, The OA. parameters have physical basis and consid erable prior research has focused on relating these parameters to soil textural classification. However, the original GB method is limited i n that it is applicable only for a single pending period. An explicit Green and Ampt redistribution (GAR) technique is developed herein to e stimate interstorm redistribution of soil water and allow multiple pen ding simulations using the GPI. methodology Soil water redistribution during interponding periods is estimated using the physical constructs of water retention curves without hysteresis. A GA wetting-front suct ion parameter scaling function is derived for use between arbitrary so il water contents. Simulations on 11 soil textural classifications com paring the GAR method with the numerical solution of Richards equation reveal that the GAR method is a viable technique for estimating infil tration for multiple pondings with acceptable error.