Applications of the Numerical Method of Lines (NMOL) in Soil Hydrology

ABSTRACT Anew technique, called the numerical method of lines (NMOL), is described. It can be used to obtain numerical solutions of initial-boundary value problems in soil hydrology in a very short time. The method is very simple and does not require a strong background in advanced mathematics or computer programming. The implementation of the method does not change from problem to problem and the method is also applicable to multi-dimensional problems. A software package that implements this technique has been developed for the IBM PC or compatible computers. The technique is illustrated by solving the initial-boundary value problems in the design of drainage and sub-irrigation systems. The nonlinear Boussinesq equation is solved numerically, subject to appropriate initial and boundary conditions. Results are compared with those of Skaggs (1975, 1979). The advantages of NMOL over other conventional numerical methods are discussed.