When is the Green-Ampt model a better fit for calculating how water soaks into soil than the Horton model?

The Green-Ampt model is a better fit for calculating how water soaks into soil than the Horton model primarily when a physically-based understanding of the infiltration process, directly related to soil properties, is required. To elaborate, infiltration is the process by which water on the ground surface enters the soil. The Horton model is an empirical model, meaning it is based on observed data and a mathematical curve fit, not on fundamental physical laws. It describes infiltration rate as decaying exponentially from an initial maximum rate to a constant final rate, typically under uniform surface ponding (water standing on the soil surface). Its parameters (initial infiltration rate, final infiltration rate, and a decay constant) are fitted from experimental data and do not directly represent specific soil physical properties. In contrast, the Green-Ampt model is a physically-based model, derived from Darcy's Law and the principle of mass conservation. It idealizes the infiltration process by assuming a sharp wetting front, which is the distinct boundary between the wetted, saturated soil zone and the d....