Comparison of flux-based and head-based methods for determination of near-surface saturated hydraulic conductivity

The saturated hydraulic conductivity (Ks) plays a crucial role in understanding water entry, redistribution, and hydrological processes at the soil–atmosphere interface. This study compared head-based [mini disk infiltrometer (MDI), automated SATURO, and laboratory permeameter (PM)] and flux-based [rainfall simulator (RS)] methods for determining near-surface Ks through controlled laboratory measurements. Results showed that Ks from RS aligned well with SATURO and PM estimates. The empirical MDI method (MDI-emp) provided Ks estimates one order of magnitude higher than other methods, while an inverse estimation procedure using MDI measurements (MDI-inv) yielded results consistent with other methods. Statistical tests endorsed these findings. Three key conclusions were derived: (i) SATURO, RS, and MDI-inv were consistent in determining near-surface Ks, (ii) RS was sensitive to the mathematical formulation adopted for Ks determination, and (iii) MDI-emp method was unreliable for Ks estimation. These findings underscore the potential of SATURO and MDI-inv as handy methods for Ks evaluation.