The water table and the piezometric surface are concepts used in hydrogeology to describe groundwater and how it behaves within the Earth's subsurface. Here's a breakdown of each term:

Water Table

1. Definition: The water table is the upper surface of the zone of saturation, where the pores and fractures of the ground are completely filled with water.

2. Characteristics:

   • It separates the unsaturated zone (above) from the saturated zone (below).
   • The level of the water table can vary with seasons, precipitation, and human activities like pumping.
   • In unconfined aquifers, the water table follows the contours of the land surface.

3. Applications:

   • Understanding water availability for wells.
   • Assessing the potential for contamination.

Piezometric Surface

1. Definition: The piezometric surface is an imaginary surface representing the level to which water would rise in tightly cased wells tapping into a confined aquifer.

2. Characteristics:

   • It is specific to confined aquifers, where water is under pressure between impermeable layers.
   • Unlike the water table, the piezometric surface can be above the ground surface (resulting in artesian wells).
   • It reflects the pressure conditions in the aquifer.

3. Applications:

   • Designing and managing artesian wells.
   • Assessing groundwater flow and hydraulic gradients in confined systems.

Key Differences

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