Geography Key Defintions - RIVERS Flashcards
Erosion
The wearing away & removal of material
Hydraulic Action
The sheer force of the water hitting the river bed & banks
Abrasion
When the load carried by the river repeatedly hits the bed, dislodging particles into the flow of the river
Attrition
When stones in the river knock against each other, becoming smaller and more rounded
Solution (Erosion)
When the river flows over chalk or limestone, slowly eroding it
Vertical Erosion
When the river erodes downwards
Lateral Erosion
When the river erodes sideways
Traction
Large particles rolled on the river bed
Saltation
Bouncing of particle too heavy to be suspended
Suspension
Small sediment held in the river
Solution (Transportation)
Dissolved load
Long profile
The gradient of a river from its source to the mouth
Cross profile
The side cross section of a river or valley
Transportation
Movement of eroded material
Deposition
Material carried is dropped due to loss in energy
Interlocking Spurs
Where mountain streams weave their way through the v shaped valley
Waterfall
A step in the long profile, causes when the river flows over resistant rock
Gorge
A narrow steep sided valley formed when a river retreats upstream
Meander
A wide bend in a river
Ox-bow lake
An arc shaped lake on a floodplain caused by a cut off meander
Levee
Raised bank on either bank of a river, caused by regular flooding or man made
Floodplain
Relatively flat area formed around a river channel that sometimes floods
Estuary
Tidal mouth of where the river meets the sea—wide banks of deposited mud are exposed at low tide
Hydrograph
Graph which shows the discharge of a river, relative to rainfall over a period of time
Hard engineering
Using concrete or artificial structures to defend against natural processes
Discharge
Quantity of water that passes a given point in a period of time
Soft engineering
Managing erosion by working with natural processes to reduce flooding
Drainage basin
An area of land drained by a river & and it’s tributaries
V shaped valley
At its source a river forms a v shaped valley as it erodes downward
Flood
When river discharge exceeds river capacity and spills onto the flood plain
