Science – Society – Technology

# Table 11 Detailed nomenclature for geothermal and soil-related variables

SymbolUnitDescription
$$\alpha$$($$\text {m}^{2}\,\text {s}^{-1}$$)Thermal diffusivity
$$\gamma _{d}$$(g/$$\text {cm}^{3}$$)Dry (bulk) density
$$\gamma _{s}$$(g/$$\text {cm}^{3}$$)Particle density
$$\gamma _{w}$$(g/$$\text {cm}^{3}$$)Water density
$$\lambda$$($$\text {W K}^{-1}\,\text {m}^{-1}$$)Thermal conductivity
$$\rho$$($$\Omega$$ m)Electrical resistivity
$$\omega$$($$\text {s}^{-1}$$)Angular frequency of one period in Fourier series
$$a_{n}$$(–)First Fourier coefficient for the nth harmonics
$$b_{n}$$(–)Second Fourier coefficient for the nth harmonics
$$c_{v}$$($$\text {J m}^{-3}\,\text {K}^{-1}$$)Volumetric heat capacity
D(m)Damping depth
e(–)Void ratio
F(%)Percentage sum of sand and gravel fractions in the soil
$$h_{i}$$(m)Width of soil strata i
$$I_{1},...,I_{10}$$(–)Possible fraction intervals for soil texture variables
$$M_{s}$$(g)Mass of solid soil in ground
$$M_{w}$$(g)Mass of water in ground
n(–)Harmonics index in Fourier series
$$n_{p}$$(–)Porosity
$$R_{n}$$(–)Amplitude of nth harmonic of Fourier series solution for T
Sd, St, Cl(%)Sand, silt, and clay fraction percentage in soil
$$S_{r}$$(%)Saturation degree
t(s)Time
T($$^{\circ }$$C)Shallow ground temperature
$$T_{0}$$($$^{\circ }$$C)Average ground surface temperature over a year
$$V_{a}$$($$\text {m}^{3}$$)Volume of air in ground
$$V_{s}$$($$\text {m}^{3}$$)Volume of solid soil in ground
$$V_{T}$$($$\text {m}^{3}$$)Total volume of ground
$$V_{v}$$($$\text {m}^{3}$$)Volume of void in ground
$$V_{w}$$($$\text {m}^{3}$$)Volume of water in ground
w(%)Gravimetric water content
z(m)Ground depth
1. (−) signifies no unit