Artesian aquifer
An artesian well is a well in a valley below the water table, is in the water under pressure. This hydraulic potential is so high that the water by itself, ie without pump, rising to the earth's surface or higher. An artesian well is always artificially unlike an artesian source because it was created by a bore or a shaft.
Basics
Named after the well is the landscape Artois (French: Artois ) for the first time such a system has been created in northern France, in 1126. Scientifically, the French physicist François Arago continued deliberation on the subject.
Prerequisite for an artesian well is confined groundwater. Such is present when an aquifer ( an aquifer ) is sealed by an impermeable layer of rock upwards and at the same time the development of hydrostatic pressure, the large-scale geological structure of the aquifer allows (for example, in a bowl-shaped valley or between sloping rock layers ). Drilling or digging to an aquifer with confined groundwater in the groundwater rises to the principle of communicating vessels in the well or in the shaft up to the amount of free ( unconfined ) groundwater surface in the aquifer. If this level is higher than the ground surface at the well, ground water injected under pressure from the ground up. Artesian wells are possible only in landscape sinks.
Decreases the free groundwater surface in the aquifer due to pumping water from (ie is the water intake higher than the groundwater recharge ), diminishes the pressure of artesian well.
In Germany there are, among others, in Dresden an artesian well. Also in the Messel Pit (near Darmstadt) is one which is, however, only be seen on a guided tour. Its water is iron and sulphide, drinking water quality ( therefore jokingly "Bad Messeler healing water "). In Heilbronn, the local paper mills made the artesian wells in the early industrial period for commercial purposes advantage. The gained geological and technical experience found in appropriate professional scientific publications input and aimed to spread the presented in words and pictures Brunnenbohreinrichtungen.