The module TRACE calculates the path a particle takes in a steady-state or transient flow field over a given period of time based upon the groundwater flow calculated with TRIWACO-FLAIRS or MODFLOW. The calculation length of the pathlines (in days) can be defined by the user. For a transient groundwater model a velocity field is calculated for every timestep. The end time of the pathline calculation in this case is equal to the end time of the transient groundwater flow calculation. Calculated pathlines and velocity fields can subsequently be used as input for water quality and solute transport calculations.

Interactive pathline calculations can be carried through the using the visual presentation module TRIPLOT. The user can choose between starting pathlines from a plan- or cross sectional view. To help clarify the pattern of flow within the groundwater system vector fields can be calculated.

Pathline calculations can be done for both groundwater abstraction and injection, any user defined starting point and even for every node/cell of the grid.

Pathlines from/to wells or line-element (river)

Pathline calculations from/to well or line-elements are allowed to begin in the proximity of a groundwater abstraction- or injection well, a draining- or infiltrating river/tube. The user defines the amount of starting points from which the pathlines have to start and the calculation is stopped when the end time has been reached. The direction of the pathline (up- or downstream or both ways) can also be defined by the user.

Pathlines from a user defined point, line and area

This type of tracing is when the user defines the place (point, line or area) and depth of the starting point of pathline. The direction of the pathline (up- or downstream or both ways) can also be defined by the user.

Influence area (capture zone)