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  2. Drawdown (hydrology) - Wikipedia

    en.wikipedia.org/wiki/Drawdown_(hydrology)

    In subsurface hydrogeology, drawdown is the reduction in hydraulic head observed at a well in an aquifer, typically due to pumping a well as part of an aquifer test or well test. In surface water hydrology and civil engineering, drawdown refers to the lowering of the surface elevation of a body of water, the water table, the piezometric surface ...

  3. Well test - Wikipedia

    en.wikipedia.org/wiki/Well_test

    Often the well efficiency is determined from this sort of test, this is a percentage indicating the fraction of total observed drawdown in a pumping well which is due to aquifer losses (as opposed to being due to flow through the well screen and inside the borehole). A perfectly efficient well, with perfect well screen and where the water flows ...

  4. Aquifer test - Wikipedia

    en.wikipedia.org/wiki/Aquifer_test

    When water is pumped from the pumping well the pressure in the aquifer that feeds that well declines. This decline in pressure will show up as drawdown (change in hydraulic head) in an observation well. Drawdown decreases with radial distance from the pumping well and drawdown increases with the length of time that the pumping continues.

  5. Cone of depression - Wikipedia

    en.wikipedia.org/wiki/Cone_of_depression

    In confined aquifers , the cone of depression is a reduction in the pressure head surrounding the pumped well. When a well is pumped, the water level in the well is lowered. By lowering this water level, a gradient occurs between the water in the surrounding aquifer and the water in the well. Because water flows from high to low water levels or ...

  6. Well drainage - Wikipedia

    en.wikipedia.org/wiki/Well_drainage

    The well filter must be placed in a permeable soil layer. The spacing can be calculated with a well spacing equation using discharge, aquifer properties, well depth and optimal depth of the water table. The determination of the optimum depth of the water table is the realm of drainage research.

  7. Groundwater flow equation - Wikipedia

    en.wikipedia.org/wiki/Groundwater_flow_equation

    the water is of constant density (incompressible), any external loads on the aquifer (e.g., overburden, atmospheric pressure) are constant, for the 1D radial problem the pumping well is fully penetrating a non-leaky aquifer, the groundwater is flowing slowly (Reynolds number less than unity), and; the hydraulic conductivity (K) is an isotropic ...

  8. Moral Injury: The Grunts - The Huffington Post

    projects.huffingtonpost.com/moral-injury/the...

    Some troops leave the battlefield injured. Others return from war with mental wounds. Yet many of the 2 million Iraq and Afghanistan veterans suffer from a condition the Defense Department refuses to acknowledge: Moral injury.

  9. Water table - Wikipedia

    en.wikipedia.org/wiki/Water_table

    The slope of the water table is known as the “hydraulic gradient”, which depends on the rate at which water is added to and removed from the aquifer and the permeability of the material. The water table does not always mimic the topography due to variations in the underlying geological structure (e.g., folded, faulted, fractured bedrock).