Retention curves of soil from the Liz experimental catchment obtained by three methods

Abstract

The retention curves were measured in the soil from the Liz experimental catchment (Šumava). The sand table and pressure extractor methods were used to obtain a 13-point retention curve for undisturbed soil samples taken from 6 depths. The data points of the individual retention curves were fitted in with the analytical expression of and the reference retention curves were calculated for each depth by scaling. For the same soil, the retention curves were estimated by the artificial neural network method by and the use of the empirical Pedotransfer function. The numerical experiment, which represented the infiltration and redistribution processes, was conducted using of all three sets of retention curves. Simulated water storages and pressure fields obtained using two sets of estimated parameters produced similar results, however they did not approximate well the modelling results obtained with the use of the measured reference parameter set. Of the two sets of pedotransfer functions (PTFs), which have been tested in this study, the empirical PTF of showed a slightly better agreement with the measured retention curves. The results give a guideline for the application of the retention curves estimation by the pedotransfer function for the soil from the Liz catchment.