Determining soil hydraulic properties by parameter estimation: On the selection of a model for the hydraulic properties

摘要: Parameter estimation procedures involving solution of the inverse flow problem pertinent to a transient experiment constitute powerful method determining soil hydraulic properties. One problems associated with these is selection an appropriate model describe Three different models were considered: those van Genuchten (VG) and Brooks Corey (BC) model, exponential Gardner for hydraulic-conductivity-soil-water-pressure relationships, coupled new expression soil-water-content-soil-water-pressure relationship (GR model). For given properties determined from simulated measured outflow experiments supplemented water content at pressure head −15,000 cm H2O, using parameter procedure Kool et al. (1985a) data two soils: hypothetical sandy loam (assumed be described by VG model) silt soil. Model validation tests performed, most was selected candidate discrimination Akaike Information Criterion (AIC). In case loam, found accurate consistent data. The performance both BC GR (in terms AIC) less good but very similar each other. soil, additional m, which accounts correlation between pores path tortuosity (m=2.02) rather than constant m=0.5, when m considered as unknown instead constant.