Numerical Modeling of Soil Evaporation Process and Its Stages Dividing during a Drying Cycle

Table 1

Hydraulic conductivities for liquid-water and water vapor flux and related parameters.

Hydraulic conductivity	Parameter	Expression/constant
	Pore connectivity coefficient
	Gain factor
	Surface tension of soil water, g s^−2
	Surface tension at 25°C, g s^−2
	Vapor diffusivity in soil, m^2 s^−1
	Tortuosity factor in gaseous phase
	Vapor diffusivity in air, m^2 s^−1
	Density of liquid water, kg m^−3
	Saturation vapor density, kg m^−3
	Relative humidity of soil surface
	Molecular weight of water, kg mol^−1
	Gravitation acceleration, m s^−2
	Universal gas constant, J mol^−1 K^−1
	Enhancement factor
	Mass fraction of clay	0.02