A comparative assessment of the estimates of the saturated hydraulic conductivity of two anthropogenic soils and their impact on hydrological model simulations

Abstract

In this study, different methods were compared in order to determine the soil hydraulic conductivity at the saturation (K_s) of two heavily anthropized soils in northern Italy: an irrigated field and a landfill cover. In situ, laboratory measurements (falling head and evaporation method) and pedotransfer functions (ROSETTA and HYPRES) were used for the K_s estimation. In accordance with scientific literature, the results have shown that K_s is largely dependent on the type of technique used in taking the measurements. The ROSETTA and HYPRES pedotransfer functions show quite similar performances, while their easiness and convenient use make them potential alternative techniques for the K_s estimation in comparison with the in situ and laboratory measurements. The K_s estimate is sensitive to the selected method and this sensitivity affects the hydrological model simulations. Therefore, none of the tested methods can be considered as a benchmark, but the results found in this study confirm that the applied method for the determination of K_s, may provide a first estimate of K_s to be subsequently optimised after the simulations.