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Reviewing classical studies in soil physics“A new model for predicting the hydraulic conductivityof unsaturated porous media”
By Y. Mualem
Water Resources Research, Vol. +,, No. -, /+-ῌ/,, (+310)

and“A closed-form equation for predicting the hydraulic conductivityof unsaturated soils”
By M. Th. van Genuchten
Soil Science Society of America Journal, Vol. .., No. /, 23,ῌ232 (+32*)
Ken’ichirou KOSUGI** Graduate School of Agriculture, Kyoto Univ., Kyoto, 0*0ῌ2/*,, Japan
Key words : Water retention curve, unsaturated hydraulic conductivity, pore size distribution,
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Fig. -

Observed (open circles) and calculated(solid lines) curves for soil water retention and relative hydraulic conductivity, for Hygiene Sandstone (upper
panels) and Silt Loam G.E. - (lower
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55

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Fig. /(a) Water retention functions based on
Eq. (-0) and (b) their derivatives, whena was ﬁxed at *.*+ cm + and m waschanged. Solid circle on each dSe/dY
Y curve represents maximal dSe/dY
value.

Fig. 0(a) Water retention functions based on
Eq. (-2) and (b) their derivatives, when
Y* was ﬁxed at+** cm and m waschanged. Solid circle on each dSe/dY
Y curve represents maximal dSe/dY
value.

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56



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57

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