River Glossary
Rivers are complex ecosystems. Their complexity is reflected in a rich and technical vocabulary, which can be daunting and confusing for anyone – those who aren’t fully immersed in a riverine way of life and also experienced river enthusiasts.
Thinking of it, we created a weekly River Glossary social media series, which started in January and finished in July, where we brought river-related words and explored their meanings. You can read the full list below.
A
Abrasion: process in which rocks and sediments wear down the riverbed and riverbanks, contributing to erosion.
Abstraction: the process of extracting water from a natural source (rivers, lakes, groundwater, etc.) for use in agriculture, industry or drinking water supply.
Affluent: a body of water which flows into the largest stream or river, also known as a tributary.
Aggradation: accumulation of sediment in the riverbed and riverbanks resulting in land elevation.
Alluvium: sediment – clay, gravel, silt and sand – deposited by flowing water in the riverbed, floodplain, delta, or at the base of a mountain slope.
Aquifer: underground layer or layers of porous rock, sediment, or soil that hold water and allow it to flow.
B
Backwater: a part of a river with little or no current.
Basin: an area of land drained by a river and its tributaries.
Bed: bottom of a channel.
Bog: freshwater wetlands with wet, spongy ground where peat accumulates.
Brackish water: water that’s more saline than freshwater, but not as salty as saltwater. It may result from the mixing of fresh and saltwater as in estuaries or man-made projects such as dikes.
Buffer strip: vegetation barrier between aquatic and terrestrial zones designed to filter out pollution before it reaches the water.
C
Canal: man-made waterways built for irrigation, shipping, travelling and other purposes.
Catchment: an area of land where water collects from the higher areas above it, usually surrounded by hills or mountains.
Channel: the deepest part of a waterway; or a narrow body of water that connects two larger bodies of water.
Channelisation: the artificial process of widening and deepening river channels to improve capacity and/or navigability.
Confluence: the meeting or junction of two or more streams; also the place where these meet.
Culvert: a buried water pipe or sewer that crosses under a road or railway.
D
Dam: a barrier or structure across a waterway built to control the flow of water.
Degradation: progressive lowering of the riverbed due to sediment removal.
Delta: an area of low, flat land, where a river splits and spreads out into several smaller streams before entering a larger body of water.
Deposition: the process through which the river deposits sediment in the river channel or in its floodplain.
Diversion: re-routing water from a watercourse, permanently or temporarily, for construction or irrigation purposes.
Drainage basin: an area of land drained by a river and its tributaries.
E
Effluent: stream fed directly by groundwater.
Embankment: artificial deposit of material used to contain, divert, or store water, support roads and railways, or for other similar purposes.
Erosion: wearing away of rock and soil in the riverbed and banks by biological, chemical, or mechanical forces.
Estuary: an area where a river meets the sea.
Eutrophication: overabundance of nutrients in a body of water leading to the excessive growth of algae and other aquatic plants. When these plants die and decompose, they deplete the water of oxygen.
F
Floodplain: an area of flat land near a river or stream naturally subject to flooding.
Flow: the volume of water moving past a particular point during a given time period.
Fluvial: a term used to describe anything related to rivers or streams.
G
Gravel: natural accumulation of rock fragments, mostly of particles larger than sand (over 2 mm).
Groundwater: water found underground in the cracks and spaces in soil, sand and rock.
H
Habitat: local environment where organisms live and grow.
Headwater: the source of a stream or river. These are located at the furthest point from where the water body empties or merges with another.
Hydrological cycle: the continuous circulation of water in the Earth-Atmosphere system – from the ground to the atmosphere and back again.
I
Inlet: a narrow body of water extending into the land from a larger water body such as a sea, lake, or river.
Infiltration: the process by which water enters the ground by seeping through pores in soil or any other surface.
L
Lake: an inland body of slowly moving or standing water, usually larger and/or deeper than a pond.
Levee: an embankment constructed to prevent a river from overflowing.
M
Meander: a sinuous curve or bend in the channel of a river or another watercourse.
Morphology: the form, shape, or structure of a stream or organism.
Mouth: where a river enters another river, lake, sea, or the ocean.
O
Outfall: the mouth or outlet of a river, stream, lake, drain or sewer.
Oxbow lake: a curved lake that was originally a bend in a river but became separated when the river took a new, straighter course.
P
Peat: spongy material formed by the partial decomposition of organic matter, primarily plants, found in wetlands.
Point source pollution: any single identifiable source of pollution, such as an outfall pipe, ditch, ship, or smokestack.
Pond: a small body of (usually fresh) water smaller than a lake.
R
Reservoir: an artificial or natural storage place for water, such as a lake, from which the water may be withdrawn for irrigation or water supply.
Riverbank: the land at either side of a river.
Riparian zone: an area of land and vegetation adjacent to a body of water and that has a direct effect on it.
Run-off: excess water that flows over the ground and reaches a waterway as a result of rainfall or snowmelt.
S
Sediment: solid material transported by water or wind and deposited in bodies of water.
Silt: a solid, dust-like sediment that’s smaller than clay that can be transported and deposited by water, ice, and wind.
Siltation: increased concentration and/or deposition of water-borne silt in a body of water.
T
Tidal: related to the regular rise and fall of the sea level due to gravitational forces.
Tributary: a freshwater stream that feeds into a larger stream or other body of water.
Trunk: the main course of a river, the primary pathway for water flow within a river system.
V
Velocity: the speed of water flowing in a watercourse.
V-shaped valley: formed by erosion from a river or stream over time, it’s characterised by steep and often rugged sides.
W
Wastewater: used water that has been affected by domestic, industrial or commercial use.
Waterfall: a flow of water that cascades over the edge of a cliff and falls into a pool below.
Watershed: a land area that channels rainfall and snowmelt to creeks, streams, and rivers, and eventually to outflow points such as reservoirs, bays, and the ocean.
Weir: a low barrier which is built across a river in order to control or direct the flow of water.