Author : M. R. Namitha 1
Date of Publication :23rd November 2017
Abstract: In this study, the unsaturated hydraulic conductivity (K) of sandy loam soil was determined through inverse modelling. The transient unsaturated water flow was simulated by numerically solving the Richards equation with the finite element code of Hydrus-1D. The cumulative infiltration flux across a boundary at different time was used as the input variable to optimise the soil hydraulic parameters. The inverse method generally uses a weighted least-squares approach in which numerically simulated data are fitted to the measured data. van Genuchten hydraulic model was chosen for the determination of unsaturated hydraulic conductivity. The soil hydraulic parameters viz. residual water content (θr), saturated water content (θs), inverse of air entry value (α), water retention parameter (n), and saturated hydraulic conductivity (Ks) were optimised in successive iterations. The optimised parameter values were fitted in the van Genuchten model for obtaining the unsaturated hydraulic conductivity of the proposed soil
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