Estimation of hydraulic conductivity function in unsaturated pyroclastic soils

A full understanding of slope failure conditions in unsaturated pyroclastic slope needs a fair analysis of groundwater flow and, therefore, a proper hydraulic soil characterization in terms of either soil water retention curves (SWRC) and hydraulic conductivity function (HCF). A practical method to detect the HCF by processing in situ data is provided, thus, the identification of the HCFs operating on site by applying the Soil Water Balance (SWB) to the pyroclastic soil cover is carried out. In this regard data monitoring (matrix suction and volumetric water content) collected at experimental field of Monteforte Irpino in Southern Italy over four years have been used. Moreover a comparison between the saturated hydraulic conductivity from lab test and from in situ measurements is carried out and the results confirm that the effective hydraulic conductivity operating at the site scale is higher than the hydraulic conductivity obtained in the laboratory for the whole range of suction measured at site.