Terms of Hydrology (G)

gaining stream :

Stream or stretch of stream which receives water from the saturated zone, a ...

gauge datum; gage datum (A) :

Vertical distance of the zero of a gauge referred to a certain datum level. ...

gauge height; gage height (A) :

Height of a water surface above a gauge datum. It is used interchangeably w ...

gauge zero; gage zero (A) :

Elevation at which a water level gauge zero is set.

gauging section; gaging section (A) :

Cross-section of an open channel in which measurements of depth and velocit ...

gauging site; gaging site (A) :

Location on a stream where measurements of water level and discharge are re ...

geothermal gradient :

Increase in temperature of the Earth per unit of depth (approximately 3.3°C ...

geyser :

Intermittent thermal spring throwing up a column of hot water.

glacier :

Accumulation of ice of atmospheric origin generally moving slowly on land o ...

glacier flood :

Sudden outburst of water released by a glacier.

glacier ice :

Any ice in, or originating from, a glacier, whether on land or floating in ...

glaciology :

Science dealing with the properties and occurrence of ice, ice accumulation ...

global circulation :

General term for the motion system of the Earth's atmosphere embracing the ...

graded stream :

Stream that apparently has achieved an approximate state of equilibrium bet ...

gradex method :

Method which allows the substitution of a frequency distribution for floods ...

grading :

Degree of mixing of size classes in sedimentary material. Well graded impli ...

grains of ice :

Frozen raindrops or largely melted and refrozen snowflakes. Former name for ...

gravel pack :

Graded, porous material introduced into the annular space between the casin ...

gravitational water :

Water in the unsaturated zone which moves under the influence of gravity.

Gravity flow :

Flow of water in which the effect of gravity is predominant.

grease ice :

Thin film of ice, floating on the surface at the start of ice formation and ...

gross interception loss :

Rainfall evaporated from canopy and litter.

ground data :

Information obtained on surface/subsurface features to aid in interpretatio ...

ground track :

Vertical projection of the actual flight path of an aerial or space vehicle ...

groundwater :

Subsurface water occupying the saturated zone.

groundwater basin :

Physiographic unit containing one large or several connected or interrelate ...

groundwater dam :

Body of material which is impermeable or has only low permeability and whic ...

groundwater dating :

Determination of the time between the recharge of groundwater and its sampl ...

groundwater depletion curve :

Curve showing the rate of release of water from storage in an aquifer.

groundwater divide :

Line on a water table or piezometric surface on either side of which the gr ...

groundwater flow :

Movement of water in an aquifer.

groundwater hydrology :

That branch of hydrology which deals with groundwater, taking into account ...

groundwater level :

Elevation, at a certain location and time, of the water table or piezometri ...

groundwater mining :

Withdrawal from an aquifer containing fossil water.

groundwater mound :

Mound-shaped or ridge-shaped feature in a groundwater table, built up by in ...

groundwater overexploitation :

Withdrawal from a groundwater reservoir in excess of the average rate of re ...

groundwater recession :

Decreasing rate of groundwater discharge to surface water bodies during per ...

groundwater runoff :

That part of the runoff which has passed into the ground, becomes groundwat ...

groundwater station :

Station at which data on groundwater are obtained on one or more of the fol ...

groundwater storage :

Quantity of water in the saturated zone of an aquifer. (IGH)

gully :

Channel deeply eroded by water which flows only due to storm-water runoff a ...

guttation :

Process by which plants expel liquid water from leaves in excess of transpi ...

gutter :

Shallow waterway provided at the margin of a highway for surface drainage.