Diagonally dominant matrices for the finite element method in hydrology

The finite element method provides a powerful new instrument in the solving of problems of flow in the subsoil by means of a numerical processor. This new technique may be reinforced, without complicating its numerical aspect, by an appropriate choice of the sub‐regions into which the original region is divided. In two‐dimensional confined flows particular types of triangular meshes may be adopted which ensure the final matrices to be diagonally dominant both in steady‐state and transient conditions, in heterogeneous and anisotropic fields. This will allow the utilization of rapidly converging iterative processes in the solution of the final linear systems with a notable saving of processing time.