The analysis of infiltration, especially when infiltration experiments are used to estimate soil hydraulic properties, is becoming increasingly important for the geosciences community. Indeed, infiltration process is an important component of the hydrological cycle; it refers to the entry into the soil of water and all substances transported by it. Thus, estimates of soil infiltrability are mandatory key tasks to be performed on a number of hydrologic, agronomic, ecological or environmental studies. Under natural conditions, infiltration is characterized by high spatial variability resulting from a high degree heterogeneity of both soil texture and structure. On the other hand, local infiltration experiments are sensitive to space-time variability of the unsaturated soil properties. High-resolution infiltration measurement is crucial to properly describe and analyze soil water properties needed to model soil water flow. The aim of the session focus is on the principles, capabilities, and applications of both infiltration techniques and models at different scales, including, but not limited to: - field infiltration measurements for a wide variety of infiltration devices, from the most simple to the most sophisticated and complete, combined to complementary information provided by other methods (i.e., TDR probes, GPR, ERT, etc.), - new or revisited numerical and analytical models to account for multiple-porosity, hydrophobicity, organic matter, or swelling on infiltration, clogging, biofilm development; and many other factors that are not taken into account in classic infiltration models, - estimation of soil hydraulic parameters, among which the saturated-unsaturated hydraulic conductivity and sorptivity which are fundamental in soil science. We will explore diverse topics of infiltration and interactions encompassing soil processes. The session is not limited by methodology or approach and we welcome studies including laboratory or numerical simulation of infiltration, in-situ studies of water and solutes infiltration. We welcome contributions from simulated and real data investigations in the laboratory or field, successful and failed case studies as well as the presentation of new and promising infiltration approaches.