DERIVING VERTICAL SATURATED HYDRAULIC CONDUCTIVITY OF SOIL USING DOUBLE RING INFILTROMETER INFILTRATION INFORMATIOM

摘要

Making accurate estimations of saturated hydraulic conductivity (K_S) in Double Ring Infiltrometer (DRI) test requires considering the effects of soil type, initial water content of the soil, ring depth, and head of ponding on measured infiltration rate. Besides, measuring the effect of rings diameters on calculated infiltration rate enables us to use different sizes of the ring. Smaller rings are preferred due to their lighter weight and fewer water requirements. In this study, by conducting 30 DRI lab experiment, 10 DRI field tests, and 864 simulated DRI tests using finite element program HYDRUS-2D, the effects of these parameters on measured infiltration rates were observed and, based on M5 trees model, a formula was generated to predict the K_S of the soil. The accuracy of the equation was later estimated by applying the equation on real DRI test parameters and comparing the predicted K_S values with the real values measured by Guelph permeameter in the field.