Bidimensional Model for the Numerical Solution of Richards Equation

摘要

Richards equation was subject to an integral interpolation and a discrete nonlinear finite difference scheme was obtained. When this scheme was applied to the solution domain, a nonlinear equation system resulted that could be solved using a Picard-type iterative procedure. A linearized version of the Richards equation was obtained through the use of fixed coefficient criteria and the adoption of an exponential relationship between hydraulic conductivity and the matric potential. The corresponding scheme of finite differences was generated and used to analyze the consistency, truncated error, stability and precision of the nonlinear system. Finally, using numerical evidence from the simulation of several problems, it was shown that the precision conditions of the linear scheme are applicable to the nonlinear model.