Terms of Hydrology (B)

backwashing :

Reversal of the flow of water under pressure, for example in a well to free ...

backwater curve :

Longitudinal profile of the water surface upstream in a stream where the wa ...

baffle :

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

bank (left, right) :

Rising land bordering a river margin of a channel at the left-hand (right-h ...

bank storage :

Water absorbed and stored in the permeable bed and banks of a stream, lake ...

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 or at its ...

barrage :

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

Barrier :

Obstruction to the flow of surface water or groundwater.

base flow :

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

base level of erosion :

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

base-width (of a flood hydrograph) :

Time interval between the beginning and the end of the direct runoff produc ...

basin :

Drainage area of a stream, river or lake.

basin response :

Manner in which a basin reacts to a meteorological event or sequence of eve ...

beach :

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

beam width :

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

Beaufort scale :

Wind-force scale, originally based on the state of the sea, expressed in nu ...

bed load :

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

bed material :

Sediment mixture of which the bed is composed. Bed material particles may b ...

bed profile :

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

bed-load discharge :

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

bed-load trap :

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

bed-material load :

That part of the total sediment transport which consists of bed material an ...

belt of fluctuation :

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

bench-mark :

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

bench-mark station :

Hydrological station established in each country or natural region to provi ...

bend :

Change in the direction of a stream.

benthon :

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

bifurcation :

Division of a stream into two branches.

bifurcation ratio :

Ratio of the number of stream segments of a given order in a river basin to ...

bio-assay :

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

biochemical oxygen demand (BOD) :

Index of water pollution which represents the content of biochemically degr ...

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 connected by sur ...

Bog :

Area of wet spongy ground too soft to bear the weight of any heavy body upo ...

boil :

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

border spring :

Spring formed against a barrier boundary such as an upper confining bed, or ...

bored well :

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

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 differential equatio ...

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 sensible heat to ...

brackish water :

Water containing salts at a concentration significantly less than that of s ...

braided river :

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

breakthrough curve :

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

brightness :

Attribute of visual perception in accordance with which an area appears to ...

brine :

Very concentrated salt solution (conventionally above 100 000 mg/l) often p ...

broad-crested weir :

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

brook :

Small, shallow stream usually in continuous flow in a somewhat turbulent ma ...

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 pore space ...

buoyancy :

Resultant force, in an upward direction, exerted by water on a body which i ...

buried streambed :

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

bypass channel :

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