Experimental Investigation of Unsaturated Silt-Sand Soil Permeability

Table 1

Empirical permeability functions and soil-water characteristic and permeability coefficient curve equations.

Type	Permeability functions
		Gardner [29]
		Campbell [30]
		Ahuja [31, 32]
		Gillham [33]
		Zachmann et al. [34]
		Hillel [35]
		Davidson [36]
		Davidson [36]
		Dane and Klute [37]
		Weeks and Richards [38]
		Wind [39]
		Weeks and Richards [38]
		Gardner [29]
		Brooks and Corey [24]
			Arbhabhirama and Kridakorn [40]
		Christensen [41]
		Rijtema [42]
		Phillip [43]

Note. a and b are constants; k is coefficient of permeability where subscripts w and s denote unsaturated and saturated, respectively; S is the effective degree of saturation; is the matric suction; is the volumetric water content.