Water Resources Research · 1996 · 734 citations · 22 references
Geotechnical EngineeringHydrogeologyLognormal Distribution ModelLognormal Distribution LawFluid PropertiesEngineeringSoil PropertySoil ModelingCivil EngineeringRetention ModelPore Radius DistributionSoil PhysicEarth ScienceUnsaturated Soil MechanicsHydraulic PropertySoil Mechanic
The soil water retention model of Kosugi was adapted to fit Mualem's framework, linking its parameters to the pore‑radius distribution and the water‑content–capillary‑pressure curve. The study derives a modified water‑retention model by applying a lognormal distribution to the soil pore‑radius distribution. The authors derive the model using a lognormal pore‑radius distribution and validate its accuracy with observed data from six soils. The model yields acceptable matches to observed water‑retention curves and hydraulic conductivities in five of six soils, and its θ–ψ and K r–ψ (or K r–θ) curves are generally similar to van Genuchten's model.
The soil water retention model developed by Kosugi was modified to be compatible with Mualem's model in order to derive an analytical expression for the relative hydraulic conductivity K r . The modified water retention model is to be derived by applying a lognormal distribution law to the soil pore radius distribution function. Parameters of this retention model have physical significance on the water content (θ)– capillary pressure (ψ) curve and are related directly to the statistics of the pore radius distribution. The accuracy of the resulting combined water‐retention‐hydraulic‐conductivity model is verified for observed data sets for six soils. Results showed that the proposed model produces acceptable matches with observed water retention curves and adequate predictions of hydraulic conductivities in five out of six cases. The θ − ψ and K r − ψ (or K r − θ) curves generated by this model are generally similar to those generated by van Genuchten's model.
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