It moves against gravity to rise above its initial level in artesian set-ups.
An idealized distribution of this substance is modeled using a potentiometric surface. The DupuitÂ–Forchheimer approximation accurately models its movement in two dimensions. A solid form of this material is converted into its liquid form below the so-called "active layer." It is responsible for the creation of travertine structures and produces structures called speleothems. This material's fluctuations in shape leads to a characteristic cone of depression. This substance feeds into gaining streams, and it percolates from the zone of saturation. It moves against gravity to rise above its initial level in artesian set-ups. The amount of movement of this material is typically expressed by the hydraulic head and formally described by Darcy's law. For 10 points, identify this substance that can be found in aquifers.
An idealized distribution of this substance is modeled using a potentiometric surface.
groundwater [prompt on "water"]