A scaling procedure for straightforward computation of sorptivity

Abstract. Sorptivity is a parameter of primary importance in the study unsaturated flow soils. This hydraulic required to model water infiltration into vertical soil profiles. can be directly estimated from functions (water retention and conductivity curves), using integral formulation Parlange (1975). However, calculating sorptivity this manner requires prior determination diffusivity its numerical integration between initial final saturation degrees, which may difficult some situations (e.g., coarse with that are quasi-infinite close saturation). In paper, we present procedure compute scaling parameter, cp, corresponds unit (i.e., values for all parameters zero residual content) utterly dry at state saturated state. The cp was computed numerically analytically five models: delta Green Ampt), Brooks Corey, van Genuchten–Mualem, Genuchten–Burdine, Kosugi. Based on results, proposed brand new analytical expressions models validated previous formulations other models. We also tabulated output so they easily used determine actual value any case. At same time, our results showed relation shape strongly depends chosen model. These highlight need careful selection proper description when estimating sorptivity.