Roman Letters

A = specific surface area of the medium, L-1

C = capillary hydraulic storage function, L-1

D = soil water diffusivity, L2/ T

h = soil-water pressure head, L

hE = air-entry potential head, L

H = total soil-water potential head, L

K = soil hydraulic conductivity, L/ T

Ks = saturated soil hydraulic conductivity, L/ T

m = parameter in the VG retention curve, dimensionless

n = parameter in the VG retention curve, dimensionless n, = parameters in Eq. (5.98), dimensionless

N = thermalized neutron count rate, dimensionless

Nr = "reference" count rate, dimensionless p = soil porosity, dimensionless

Pc = capillary pressure, F/L2

Pnm = pressure of nonwetting fluid phase, F/L2

Pw = pressure of wetting fluid phase, F/L2

q = volumetric water flux density, L/ T

Reff = effective radius of the meniscus in a capillary tube, L

s = degree of saturation, dimensionless

S = sources or sinks of water in the system, T-1

Se = effective saturation, dimensionless t = time, T

T = temperature, K

Vs = volume of solids, L3

Vt = total volume of the soil body, L3

Vw = volume of water, L3

w = gravimetric soil water content, dimensionless wd = mass of the dry soil sample, M

ww = mass of the wet soil sample, M

z = elevation, gravitational head, L

V = gradient operator, L-1

V2 = Laplace operator, L-2

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