Why do I get different pathlines when at different zoom levels?
WhAEM uses a numerical integration process, which is part of the GFLOW1 Solver, for tracing pathlines. The step size is fixed and defined as a percentage (2%) of the horizontal size of the window setting in WhAEM. Consequently, for a large window (zoomed out) the step size is large and the pathline trace may be inaccurate. This is often evident from the hooky nature of the trace near the well. There are two remedies: (a) zoom in to the area where you expect the capture zone to occur or (b) select a smaller step size on the Model>Settings>Tracing tab. The small window option is the most reliable. If you need to have a larger window, you may first trace in a zoomed in window and after the capture zone is complete zoom out to the desired window. This will maintain tracing accuracy (unless you do a new trace, of course).
