Vol. 12, Special Issue 11 (2023)

Author(s):
Devappa, Ravikumar V, Akshaya KA and Kathirvel L

Abstract:
Movement of water in soil is the important processes that influence the quality of soil and water in the environment. Soil water movement occurs under saturated as well as unsaturated conditions. At the start of the experiment, infiltration rate was higher as the free-soil pores allows more water into it. As time passes, the infiltration rate decreased as the soil pores get partially filled with water. 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. After 37 min. of the experiment, the observed cumulative infiltration was 7.4 cm and data simulated by Hydrus-1D at 37 min was 7.53 cm which was almost similar to the observed data. Similarly, at 372 min, the observed and fitted data were 57.5 and 58.33 cm respectively and with this, optimized parameter values were confirmed. Hydrus-1D allows the optimization of parameters using Marquardt Levenberg optimization algorithm. The optimised parameter values were fitted in the van Genuchten model for obtaining the unsaturated hydraulic conductivity of the proposed soil.