Sand model of groundwater flow against pressure gradients and ‘up the hill’

Groundwater flow between recharge areas and discharge areas penetrates first downwards under the recharge area and later upwards under the discharge area. Dissolved contaminants follow the same flow path. Groundwater does not flow parallel to the ground water table.

Previously we showed drawings of a simple groundwater flow system and of the forces acting upon groundwater. Here we show photographs of the sand model and an animations of groundwater flow against pressure gradients and ‘up the hill’. In the animation, groundwater flow is highlighted by injecting slugs of food colour. The density of the water - both with and without food colour - is 1 g/cm³. The results agree well with the mathematical simulation of this system.