Scaling hydraulic properties of a macroporous soil

Macroporous soils exhibit significant differences in their hydraulic properties for different pore domains. Multimodal hydraulic functions may be used to describe the characteristics of multiporosity media. I investigated the usefulness of scaling to describe the spatial variability of hydraulic conductivity (K(h)) functions of a macroporous soil in Las Nutrias, New Mexico. Piecewisecontinuous hydraulic conductivity functions suitable for macroporous soils in conjunction with a hybrid similar mediafunctional normalization scaling approach were used. Results showed that gravitydominated flow and the related hydraulic conductivity (K(minus;h) functions of the macropore region are more readily scalable than capillarydominated flow properties of the mesopore and micropore regions. A possible reason for this behavior is that gravitydominated flow in the larger pores is mostly influenced by the pore diameter which remains more uniform as compared to tortuous mesopores and micropores with variable neck and body sizes along the pore length.

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