Abstract
The objective of this study was to solve the Richards equation by constrained interpolation profile (CIP) method for unsaturated homogenous soil. The Richards equation was divided into advection and non-advection phases. Advection phase was approximated by CIP method while, the non-advection phase was approximated by explicit method. For the computational purpose, MATLAB platform (version 7.12.0) was used. The CIP method was applied for 12 soil types. However, this paper analyzed the results of four major soil types; sand, loam, silt and clay. The CIP outputs for all soil types displayed common pattern and agreement with the available literatures. The simulated results were compared with those of well-known Hydrus-1D model. The CIP outputs showed well agreement with Hydrus-1D. The proposed method could be a useful tool for predicting the infiltration as well as water movement in the vadoze zone.
