Rock or sediment in a formation, group of formations, or part of a formation that is saturated and sufficiently permeable to transmit economic quantities of water to wells and springs.
Applied Hydrogeology. Third edition. C.W.Fetter


Cylinder of rock, with a diameter of several centimeters. Every independent part must be identified. One core sample can contain several cuttings that can be put in different boxes. (For an example, see for the Poitiers site)


(Unit = µS/cm)

The electrical conductivity of a water is the conductance of a water column between two metallic electrodes of 1 cm² surface and separated of 1cm. The conductivity unit is micro-siemens per centimeter (µS/cm). The conductivity is an expression of the total mineralization of the water. The conductivity value depends of the temperature and is generally given for a temperature of 25°C. For a water of a conductivity Ct at a temperature t in Celsius degrees, the conductivity C25°C at the temperature 25°C is:

C25°C =Ct/1+0, 02(t-25)

Well Screen

A tubular device with either slots, holes, gauze or continuous-wire wrap; used at the end of a well casing to complete a well. The water enters the well through the well screen.

Piezometric level

(Unit: meter)

Water level measured in a piezometer.


The ability or measurement of a rock's ability, to transmit fluids. The symbol most commonly used for permeability is k, which is measured in units of darcies or millidarcies. (

When a construction will be characterized, the permeability indicated will described the horizontal flow in the porous media.


(Unit: meter)

A lowering of the water table of an unconfined aquifer or the potentiometric surface of a confined aquifer caused by pumping of ground water from wells.
Applied Hydrogeology. Third edition. C.W.Fetter



The resistivity is inverse of the conductivity; the unit is (