hydraulic head

views updated May 08 2018

hydraulic head In general, the elevation of a water body above a particular datum level. Specifically, the energy possessed by a unit weight of water at any particular point, and measured by the level of water in a manometer at the laboratory scale, or by water level in a well, borehole, or piezometer in the field. The hydraulic head consists of three parts: the elevation head (see ELEVATION POTENTIAL ENERGY), defined with reference to a standard level or datum; the pressure head, defined with reference to atmospheric pressure; and the velocity head. Water invariably flows from points of larger hydraulic head to points of lower head, down the hydraulic gradient.

hydraulic head

views updated May 21 2018

hydraulic head In general, the elevation of a water body above a particular datum level. Specifically, the energy possessed by a unit weight of water at any particular point, and measured by the level of water in a manometer at the laboratory scale, or by water level in a well, borehole, or piezometer in the field. The hydraulic head consists of three parts: the elevation head (see elevation potential energy), defined with reference to a standard level or datum; the pressure head, defined with reference to atmospheric pressure; and the velocity head. Water invariably flows from points of larger hydraulic head to points of lower head down the hydraulic gradient.