Numerical Model to Simulate Soil Wetting Pattern under Drip Irrigation System

Abstract

Background: A properly designed drip irrigation system increases the efficiency of irrigation water and its design is based on the soil wetting pattern. Methods: In this study, a numerical model has been developed using one-dimensional Richard’s Equation to simulate soil wetting pattern under drip irrigation. A fully implicit finite-difference scheme has been used to solve the governing equations with suitable initial and boundary conditions. An experiment was also conducted to analyse the wetting pattern in sandy loam soil. Wetting front computed by numerical model has been compared with the experimental wetting front at different time interval of drip irrigation system. The present model is also validated with the results available in the literature. Result: Statistical indices - root mean square error, percentage bias and coefficient of determination have been used to evaluate the model’s performance. The computed results are closely matched with the and experimental results with RMSE is less than 3, PBIAS less than 6% and R2 greater than 0.96 and also with the earlier models with RMSE is less than 0.01, PBIAS less than 4% and R2 greater than 0.98, It shows that the present model can simulate soil wetting pattern in the drip irrigation system.