Terms of Hydrology (B)

backwashing :

Reversal of the flow of water under pressure, for example in a we ...

backwater curve :

Longitudinal profile of the water surface upstream in a stream wh ...

baffle :

Wall or blocks placed in a stream to dissipate energy or to cause ...

bank (left, right) :

Rising land bordering a river margin of a channel at the left-han ...

bank storage :

Water absorbed and stored in the permeable bed and banks of a str ...

bankfull stage :

Stage at which a stream just overflows its natural banks.

Bar :

Bank of sediment, e.g. sand or gravel, deposited on a stream bed ...

barrage :

Barrier across a stream provided with a series of gates or other ...

Barrier :

Obstruction to the flow of surface water or groundwater.

base flow :

Part of the discharge which enters a stream channel mainly from g ...

base level of erosion :

Level below which a land surface cannot be eroded by running wate ...

base-width (of a flood hydrograph) :

Time interval between the beginning and the end of the direct run ...

basin :

Drainage area of a stream, river or lake.

basin response :

Manner in which a basin reacts to a meteorological event or seque ...

beach :

Belt or zone which extends along the water line, occupied by unco ...

beam width :

Measure of the concentration of power of a directional antenna. ( ...

Beaufort scale :

Wind-force scale, originally based on the state of the sea, expre ...

bed load :

Sand, silt, gravel and rock detritus, mainly not in suspension, c ...

bed material :

Sediment mixture of which the bed is composed. Bed material parti ...

bed profile :

Shape of a stream bed in a vertical plane it may be longitudinal ...

bed-load discharge :

Amount (weight, mass or volume) of bed load transported through a ...

bed-load trap :

Device for catching and/or measuring sediment moving on or along ...

bed-material load :

That part of the total sediment transport which consists of bed m ...

belt of fluctuation :

That part of the lithosphere which, because of the fluctuations o ...

bench-mark :

Permanent mark, natural or artificial, at a known elevation in re ...

bench-mark station :

Hydrological station established in each country or natural regio ...

bend :

Change in the direction of a stream.

benthon :

Organisms dwelling adjacent to the bottom sediment in a water bod ...

bifurcation :

Division of a stream into two branches.

bifurcation ratio :

Ratio of the number of stream segments of a given order in a rive ...

bio-assay :

Method for testing toxic effects of water with the help of living ...

biochemical oxygen demand (BOD) :

Index of water pollution which represents the content of biochemi ...

biomass :

Total mass of living material in a given body of water. (ISO/6107 ...

blind drainage :

Areas in which surface flow collects in sinks or lakes not connec ...

Bog :

Area of wet spongy ground too soft to bear the weight of any heav ...

boil :

Upward flow of water in a sandy formation due to an unbalanced wa ...

border spring :

Spring formed against a barrier boundary such as an upper confini ...

bored well :

Well that is excavated by means of a hand or power auger, the mat ...

bottom current :

Movement of water along the bottom of reservoirs or rivers.

boundary conditions :

Set of conditions to be satisfied by the solution of a differenti ...

boundary of saturation :

Interface between saturated and unsaturated soil.

Boussinesq's approximation :

Extension of Dupuit's approximation for unsteady flow in aquifers ...

Bowen ratio :

At a water surface, the ratio of the energy flux upward as sensib ...

brackish water :

Water containing salts at a concentration significantly less than ...

braided river :

Part of a river system in which the flow passes through a number ...

breakthrough curve :

Curve expressing the time variation of tracer concentration (e.g. ...

brightness :

Attribute of visual perception in accordance with which an area a ...

brine :

Very concentrated salt solution (conventionally above 100 000 mg/ ...

broad-crested weir :

Weir of such crest length in the direction of flow that critical ...

brook :

Small, shallow stream usually in continuous flow in a somewhat tu ...

bubble gauge; bubble gage (A) :

Gauge using a gas-purged system to measure water level.

bulk density of soil :

Mass of an oven-dry soil sample per unit gross volume (including ...

buoyancy :

Resultant force, in an upward direction, exerted by water on a bo ...

buried streambed :

Stream bed which has been buried below volcanic or alluvial depos ...

bypass channel :

Channel built to divert flows from a point upstream of a region t ...