Figure A1. Expected patterns of hydraulic head as a function of stratigraphic position. (A) Two distinct aquifers with a significant downward hydraulic gradient; (B) two distinct aquifers with a significant upward gradient; (C) two distinct aquifers with no significant vertical gradient (D) a single thick aquifer or multiple thin aquifers with no significant vertical gradient; (E) a single aquifer with (apparently) two distinctly different hydraulic heads; and (F) a single aquifer with an apparent continuum of heads.

First posted February 5, 2013