Estimating of in-situ hydraulic conductivity related with evaluating of rainfall infiltration behavior in shallow ground

Komatsu, Mitsuru*; Nishigaki, Makoto*; Seno, Shoji*; Tagishi, Hirotaka*; Takenobu, Kazuyoshi*; Kishi, Atsuyasu

Infiltration rate at the ground surface is one of the essential boundary conditions for a quantitative evaluation of groundwater flow. Conventional method for quantifying infiltration rate based on the water budget, however, includes significant uncertainties resulting from different types of quantities to be measured. In this study, focusing on a method where the infiltration rate is estimated directly from temporal changes in soil water contents in the region of interest, the measurement data was confirmed based on the unsaturated hydraulic tests. Then, the reliability of the measurement was verified by comparing the data to the laboratory test results and uncertainties associated with the measurements were quantified.