WDA Consultants Inc. - Hydrodynamic Migration of Contaminants


why

... does Groundwater flow against pressure gradients and 'up the hill'?

The driving force for groundwater flow is the gravitational force field.

In recharge areas gravitational forces cause flows against pressure forces. In discharge areas pressure potential forces cause flow against gravitational forces.

The diagram below shows the vector forces involved.

Weyer, 1977
K.U.Weyer, 1978. Mémoire du B.R.G.M., vol. 91, pp.285-297, Fig. 5
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Schematic parallelograms of forces along a groundwater flowline
under recharge and discharge areas.