In the mass continuity equation ";the partial time derivative of theta equals the negative of the partial derivative of z times q,"; this equation is plugged into q to derive the Richards equation.
In the mass continuity equation ";the partial time derivative of theta equals the negative of the partial derivative of z times q,"; this equation is plugged into q to derive the Richards equation. The Green-Ampt integral formula is often used instead of this one to predict values since it takes into account cumulative depth. This semi-empirical formula was found to overestimate its value when the substance in question is a gas, which can be rectified using the Klinkenberg correction. Often used to quantify infiltration, this equation can be simplified into a 2D form using the Dupuit assumption so that the vertical pressure gradient is only a function of the specific weight. In this equation, the viscosity, pressure head, and porosity all affects the discharge rate of the substance in question. For 10 points, name this formula, which is often used to model the flow of groundwater through a porous medium.
In the mass continuity equation ";the partial time derivative of theta equals the negative of the partial derivative of z times q,"; this equation is plugged into q to derive the Richards equation.
Darcy's Law [or anything mentioning Darcy, such as Darcy's formula,  Darcy's equation]