Terms of Hydrology (İ)

ice :

Solid form of water.

ice age :

Particular period of a geological era during which extensive ice sheets (co ...

ice break-up :

Disintegration of an ice cover.

ice cap :

Dome-shaped glacier usually covering a highland area.

ice cover :

Ice on the surface of an open body of water, e.g. a lake or river.

ice drift :

Movement of ice fields or floes in lakes and reservoirs, caused by wind or ...

ice forecast :

Statement of expected ice phenomena for a specified period and for a specif ...

ice jam :

Accumulation of ice at a given location which, in a river, restricts the fl ...

ice laying :

Duration of ice cover.

ice pellets :

Precipitation of transparent or translucent pellets of ice, which are spher ...

ice reef :

Pressure ridge formed in an ice sheet.

ice regime phase :

A specified state of the ice regime of rivers, lakes and reservoirs, which ...

ice run :

Movement of ice or slush ice with the current of a stream.

iceberg :

Large mass of floating or stranded ice, more than 5 m above sea-level, whic ...

image :

Recorded representation of an object produced by optical, electro-optical, ...

image enhancement :

Manipulation of image density to see more easily certain features of the im ...

imbibition :

Process by which a non-wetting fluid in a porous medium is displaced by a w ...

impervious :

Having a texture that does not permit water to move through it perceptibly ...

impervious boundary :

Boundary of a flow domain through which no flow can take place because of g ...

impoundment :

Body of water formed by collecting water, as by a dam.

inbank capacity :

Discharge conveyed in a water course without overtopping the banks.

incised river :

River which has cut its channel through the bed of the valley floor.

inclined gauge; inclined gage (A) :

Sloping water level gauge graduated to indicate vertical heights.

index of determination :

Index equal to one minus the coefficient of determination.

induced recharge :

Withdrawal of groundwater at a location adjacent to a stream or body of sur ...

infiltration :

Flow of water through the soil surface into a porous medium.

infiltration capacity :

Maximum rate at which water can be absorbed by a given soil per unit area u ...

infiltration coefficient :

Ratio of infiltration to rainfall.

infiltration gallery :

Low gradient closed conduit (drain or tunnel) dug into an aquifer and colle ...

infiltration index :

Average rate of infiltration derived from a time intensity graph of rainfal ...

infiltration routing :

Procedure of computing the downward movement of water through an unsaturate ...

infiltration well :

Recharge well that is sunk only into the unsaturated zone distinguished fro ...

infiltrometer :

Device for measuring the rate of infiltration.

inflow :

Flow of water into a stream, lake, reservoir, container, basin, aquifer sys ...

influent seepage :

Movement of gravity water in the zone of aeration from the ground surface t ...

initial gradient :

Minimum value of the hydraulic gradient in a soil below which there is no f ...

initial rainfall :

Rainfall at the beginning of a storm before the depression storage is compl ...

injection tank :

Device allowing the injection at a constant rate of the parent concentrated ...

injection well :

Recharge well that is sunk into an aquifer and used for direct injection of ...

inland ice sheet :

Mass of ice and snow of considerable thickness and large area.

inlet :

(1) Upstream end of any structure through which water may flow. (2) Structu ...

insolation :

Amount of direct solar radiation incident per unit horizontal area.

instantaneous unit hydrograph :

Unit hydrograph resulting from unit amount of effective precipitation appli ...

instream use :

Water use taking place within the stream channel. Examples are run-of-the r ...

insulated stream :

Stream or stretch of stream, perched or not, which with respect to groundwa ...

intake :

Structure or site, the purpose of which is to control, regulate, divert, an ...

intake area :

Area which contributes water to an aquifer, either by direct infiltration o ...

integration method :

Method of estimating quantities such as the mean velocity or mean sediment ...

intensity-duration-frequency curve :

Curve showing the probability of various short-period rainfall rates for va ...

interception :

(1) Process by which precipitation is caught and held by vegetation (canopy ...

interflow :

(1) That portion of the precipitation which has not passed down to the wate ...

intermediate belt of soil moisture :

That part of the unsaturated zone which extends from the lower edge of the ...

intermittent spring :

Spring, the discharge of which occurs only during certain periods and cease ...

intermittent stream :

Stream which flows only in direct response to precipitation or to the flow ...

interrupted stream :

Stream which contains alternating stretches of perennial and intermittent f ...

interstitial velocity :

Rate of movement of water within the pores as well as from one pore to anot ...

intertropical convergence zone (ITCZ) :

Narrow zone where the trade winds of the northern and southern hemispheres ...

intrinsic permeability :

Property of a porous medium which allows for the movement of liquids and ga ...

intumescence :

Temporary and mobile swelling of the water surface in a stream or a lake.

invert :

Lowest part of the cross section of a channel or a hydraulic structure. (TR ...

inverted capacity :

Maximum rate at which a recharge well can dispose of water admitted to it.

irrigation :

Artificial application of water to lands for agricultural purposes.

irrigation requirement :

Quantity of water, exclusive of precipitation, that is required for optimal ...

isobath :

Contour line (or surface) of equal depth of the water table below the groun ...

isochrone map :

Map or chart of a drainage basin in which a series of lines (isochrones) gi ...

isogram :

On a diagram or chart, the line of equal value of a hydrological or meteoro ...

isohaline :

Line (or surface) connecting points of equal saline content in groundwater ...

isohyet :

Line joining the points where the amount of precipitation, in a given perio ...

isolated porosity :

numerically equal to the difference between porosity and effective porosity ...

isonival :

Line of equal snow depth.

isopach :

(1) Line on a map drawn through points of equal thickness of a designated g ...

isopiestic line (or surface) :

Line (or surface) joining points of equal piezometric head.

isopleth :

Line of equal value of a function of two variables, e.g. line of equal valu ...

isopluvial :

Isopleths pertaining to rainfall for a given duration and for a given retur ...

isotherm :

Line or surface passing through points of equal temperature.

isotopic tracer :

Artificial (added to water) or natural (present in water) tracer which is a ...

isotropy :

Condition of a medium having the same properties in all directions.

isovel :

Line of equal velocity in a cross section of a watercourse.