Groundwater flow problems solved by finite elements

Abstract

Abstract described in section 1.7. Appendix 1 shows how the three-dimensional equation can be vertically integrated to give a two-dimensions-in-plan equation suitable for aquifer modelling. This equation is non-linear but further simplifications can be made to make it linear. This chapter gives examples of the solution of groundwater flow problems by finite element methods. There is a general discussion of the solution of the non-linear aquifer equation (Al.18). The linear form using estimated transmissivities can be regarded as a particular case of this. For the three-dimensional case it is possible to solve for the groundwater flow up to the phreatic surface but this is difficult because the position of this surface is initially unknown. This problem with some simplifying assumptions is discussed in section 7.6. Section 7.7 deals with the solution of the three-dimensional non-linear Richards’ equation representing groundwater flow in the saturated and unsaturated regions up to the surface of the ground.