ABSTRACT
These models use a simplified approach to describe the flow of water in the soil, especially for the water front and as a function of certain physical parameters. Among the models presented in Table 6.1, the following two models are the most commonly applied:
• Philip’s Model: Philip proposed a method to solve the equation for vertical infiltration for certain initial and boundary conditions (Table 6.1). This model introduces the concept of sorptivity, defined as the capacity of the soil to absorb water when the flow occurs only as the result of a pressure gradient. The sorptivity of the soil is represented by the infiltrated depth I in horizontal flow. It depends on the initial conditions and the boundary conditions of the system. It is a function of the initial water content of the soil Ti and the content imposed on the surface T0.
