1Professor of Soil Physics, Cornell Univ., Ithaca, N.Y.
2Soil Physicist and Graduate Research Assistant, Div. of Soil Physics, ARO, The Volcani Center
Tóm tắt
AbstractFrom results of Reichardt, Nielsen, and Biggar and of Russo and Bresler, it is inferred that a laboratory horizontal infiltration experiment with air‐dry soil yields an estimate of the saturated‐unsaturated hydraulic conductivity function given by K(h) = 0.27 m4(he/h)2.6 or K(θ) = 0.27 m4 [(θ − θd)/(θw − θd)]7.2. Here m = dx/d (t1/2); x is distance to the wetting front and t is infiltration time; θd and θw are water contents of air‐dry and “saturated” soil; h is pore water pressure head, and he is the air entry value of h. These relationships can serve as a general approximation of K(θ) and K(h) in nonsodic stable soils. Field measurements of he and saturated K can also be used to derive K(θ) and K(h).
