River Severn | River Thames

River Keywords and definitions. For photos with definition please visit our river keyword search.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Rounded pebbles and rocks

Abrasion

Abrasion is a form of erosion caused by rubbing of fine particles against an object. The effect is much the same as using sandpaper. Rivers carry sediment (fine rock particles) that abrade the banks and bed of the river channel.

Attrition

The wearing away of particles of rock as they bounce along the riverbed or knock against each other and wear away becoming more rounded.

Alluvium

The name for any material deposited by a river. (Silt is tiny material carried by running water)

B

River bank

Bank

The ground at the side of a river

Basin (Drainage basin)

The area of land that is drained by a river and its tributaries.

Bed (riverbed)

The riverbed is the ground at the bottom of the river - often made up of sand and stones.

C

River Cliff

Canal

An artificial or man-made river channel.

Channel

A groove in the land that a river flows along.

Cliff (river cliff)

A cliff is any steep slope that has been formed by natural processes. Cliffs reated by rivers are called river cliffs. They are on the outside of the curving section (meander) or a river and may be from a few metres to hundreds of metres high. Cliffs are formed when rivers cut swiftly into the land.

Current

The flow of the river.

Confluence

Where two rivers or streams meet.

D

Dam

Dam

A barrier built, usually across a watercourse, for holding back water or diverting the flow of water.

Delta

A fan-shaped area of sediment built up at the mouth of a river.

Deposition

A river lays down or drops the sediment or material that it is carrying such as sand, mud, and small stones or sticks. This often happens on the inside of meanders, because the water is flowing slowly.

Depth

How deep the water is.

Discharge

The amount of water flowing in a river per second.

Dock

A place for vessels to load and unload cargo or to be repaired.

Downstream

The direction that the river flows, towards the mouth of the river.

Drainage Basin

The area of land that is drained by a river and its tributaries. The boundary of a river basin is called the watershed.

E

Erosion

Erosion

The wearing away, in this case by water and rocks constantly rubbing

Estuary

A drowned river valley in a coastal lowland area. Occurs near or at the mouth of a river, where the tide meets the current and the fresh and salt waters mix.

F

Thames flood barrier

Fjord

A fjord is a deep, narrow flooded inlet of the sea that was formed during the last Ice Age.

Flood

Flooding happens when a river has too much water in its channel. The water breaks through the river banks and spreads over the surrounding land.

Flood barrier

A barrier forming a temporary dam that may be erected quickly or permanently alongside a river to protect a flood-prone area.

Floodplain

The flood plain is the flat land of the river valley close to the river banks. The floodplain is usually found in the lower course of a river. It is a fertile area of land, used for agriculture and growing crops.

Ford

A point where a road goes through a river.

Freshwater

Water that has no salt in it

G

Gorge

A gorge is a steep-sided river valley which is very narrow and deep. Most gorges have rocky sides. The river cuts this deep valley by erosion. Gorges are created over thousands of years.

H

Hydraulic Action

The force of the water wears away the river bank from underneath

I

Irrigation

The supply of water to farmland so that crops can grow in areas wherewater supplies are scarce or unreliable. In areas where there is not much rainfall, farmers irrigate the land, by diverting water from rivers to their fields, in channels, ditches or pipes.

L

Load

What the river carries along with it - mud, sand, rocks, wood

M

Meander

Meander

A bend in a river - usually in the middle or lower course. The meander continually changes shape as the fast flowing current of water erodes the outside bank of the meander bend and deposition occurs in the slack water of the inside of the bend.

Mouth

The end of the river. The mouth may be where the river meets the sea, a lake or a larger waterway. Most rivers flow out into the sea, and this is where they end their journey.

Moorings

The place where a ship or boat is docked (or tied up)

Mudflats

Mudflats are large area of mud that the tide washes over twice each day. They are rich in plant and animal life.

O

Oxbow lake

A small arc-shaped lake formed when a meander is sealed off by deposition. Oxbows are only found on river floodplains.

P

Pollution

Plain

A large area of nearly flat land which does not have any significant hills.

Plunge pool

A pool at the foot of a small water-fall in a river. The pool is deep because the water plunging into it has eroded the river bed.

Pollution

Materials that are not supposed to be in the river make it dirty.

Precipitation

A general term for all forms of water particles ­ rain, snow, sleet, dew, hail etc.

R

Rapids

Rapids are fast-flowing stretches of water formed where the river surface breaks up into waves because rocks are near to the surface.

Ravine

Another name for a narrow gorge.

Reservoir

A reservoir is an artificial lake created by building a dam across a river.

River

A river is a naturally winding watercourse that drains surplus water from a drainage basin.

River channels

The trenches in which rivers flow for most of the year.

Runoff

Water that has from something. Usually rain water that has a roof into a gutter, or run - off sloping ground into a channel or pond.

S

Saline

Salty water - water from the sea is known as saltwater, or saline

Saltation

Particles bouncing down a river bed. This process causes attrition, and adds to the silt and sediment in the river

Sediment

The name given to material that has been carried by rivers or the sea and then deposited. Sediment may be called alluvium if it deposited on the bed or a river, it may be called a beach when deposited by waves.

Silt

Tiny pieces of sand or rocks. These are dropped by the water on the inside of a meander where the current is slow

Source

where the stream begins: usually where there is a spring, and quite high up

Spring

A place where water naturally seeps or gushes from the ground - often in marsh or bog areas

Spur

A ridge of land that extends partly across a valley.

T

Transportation

Transportation

A process where the river moves, or transports materials (it's load) from one place to another.

Tributary

A stream or river that feeds into a larger watercourse.

U

Upstream

Opposite to the currents flow - towards the source of the river

V

Valley

A valley is a long trough in the landscape that has been eroded by a river or a combination of river and glacier action.

V-shaped valleys are usually found in the mountains and hills. They are so called because they often have very steep sides.

W

Waterfall

Watershed

High ground that surrounds a drainage basin. The boundary of a river basin.

Waterfall

A place where the river course is interrupted by a tall step.

Water table

The water table is the natural level of water in a soil or rock. Below the water table the soil or rock is saturated.