Geography Rivers

Front 1

Braiding

Back 1

Sub-dividing of a river channel - a characteristic of a river

Front 2

Corrosion

Back 2

River erosion where transported particles grind away at the river banks

Front 3

Delta

Back 3

An area of deposition found at the mouth of the river (e.g. arcuate, Nile or birds foot, Mississippi)

Front 4

Discharge

Back 4

volume of water passing a given point and time period (in cumecs or cubic metres per second)

calculation = xsa x velocity

Front 5

Drainage Basin

Back 5

Area of land, bordered by a watershed and drained by a river and its tributaries

Front 6

Flooding

Back 6

Land not normally underwater (e.g. floodplain)

Front 7

Floodplain

Back 7

Flat land immediately adjacent to the river prone to periodic flooding

Front 8

Gorge

Back 8

Steep-sided narrow valley found downstream from a waterfall

Front 9

Graded Profile

Back 9

Smooth long profile of a river that has achieved a state of equilibrium with its environment

Front 10

Hard Engineering

Back 10

Man-made structures acting as defences

Front 11

Hjulstrom Curve

Back 11

Graph showing the relationship between velocity of a river and the critical velocity needed erode or deposit a particle

Front 12

Hydraulic Action

Back 12

River erosion involving water to force air into river bank. The air compresses and weakens the bank

Front 13

Hydraulic Radius

Back 13

Measurement of channel efficiency

Calculation = xsa/wetted perimeter

Front 14

Incised Meander

Back 14

Steep-sided meander formed during a period of significant down-cutting following rejuvenation

Front 15

Kinetic Energy

Back 15

Water moves downhill, potential energy is converted to kinetic energy and used to do work

Front 16

Knick Point

Back 16

point in the river's long profile, often marked by a waterfall, that represents the extent to which a river has re-graded its profile due to rejuvenation.

Front 17

Levee

Back 17

Raised river banks formed by deposition or man-made. In a flood the water will spill over the sides

Front 18

Magnitude-Frequency analysis

Back 18

Analysis of the size (magnitude) and occurrence (frequency) of floods.

Front 19

Meander

Back 19

Sweeping bend or curve in river, characterised by having a depositional slip-off slope on the inside bend and erosional cliff on the outside

Front 20

Potential Energy

Back 20

stored energy in a still body of water that has potential to do work

Front 21

Pothole

Back 21

circular hollow or depression formed by erosion in bedrock or a river bed

Front 22

Rapids

Back 22

Series of relatively small steps in the long profile forming turbulent white waters

Front 23

Rejuvenation

Back 23

Renewed period of river erosion resulting from a fall in base level.As the river cuts down into its channel characteristic features form including incised meanders and knick points

Front 24

River terrace

Back 24

Abandoned floodplain left perched above the current floodplain following a renewed period of erosion.