Specific electrical resistivity of soil

Definition according to Cigre TB 531 chap. 4.2.3.3, 'Sequence Impedances of Transmission Lines' R.E. Fehr (2004)

Symbol

$\rho_E$

Unit

$\Omega$.m

Used in

$m_E$

Parameter m earth return

$m_{z,e}$

Parameter m earth

$p_{soil}$

Depth of image source

$\mathscr{z}_g$

Impedance earth return in ground [$\Omega$/m]

$\mathscr{z}_{gm}$

Impedance mutual earth return in ground [$\Omega$/m]

Choices

Soil type	Value	min - max
Sea water	0.1	0.01 - 1.0
Swampy ground	20	10 - 100
Damp earth	100
Dry earth	1000
Pure slate	100000000.0
Sandstone	10000000000.0