Modeling groundwater flow fields containing point singularities: Streamlines, travel times, and breakthrough curves

In the work of Charbeneau and Street (1979) a method was presented for modeling steady state groundwater flow fields containing injection and extraction wells. The Galerkin finite element method was used with greatly improved accuracy of the simulation near wells achieved by removing the singular behavior of the flow with an analytic solution for the near‐well zone, solving the nonsingular problem, and combining the results. In the present paper, methods for exploiting the improved hydraulic head solution are presented. Velocity fields are derived through differentiation of the head solution combined with smoothing and averaging. The velocity fields are used for generating systems of streamlines and determining times of travel to points of interest (including breakthrough curves for a nondispersive contaminant). The method is compared with analytical results for a single injection‐extraction well pair.