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 started a weekly River Glossary series in which we bring river-related words and explore their meanings. Keep an eye on our socials every Friday for new words, or come back here to see the full list.
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.