rivers

Created by

Mya

Cards (27)

What is a drainage basin?
An area of land drained by its river and tributaries
What is a watershed?
The boundary of two river basins
Usually on a ridge of high ground
What is the source of a river?
The point at which a river begins
What is a tributary? 
A small stream or river flowing into a main river
What is a confluence?
The point where a tributary joins a main river
What is the mouth of a river? 
The end of a river where it meets the sea
What is evaporation? 
The transfer and change of water from the ground into water vapour in the air
(The process of a liquid turning into a gas)
What is transpiration?
The transfer and change of water from plants into water vapour in the air
What is condensation? 
When water vapour is cooled down and it turns into water droplets to form clouds
What is percipitation? 
The transfer of water from the air to land.
Water can fall to earth as rain, hail, sleet or snow
What is surface runoff?
The transfer of water to the sea over the grounds surface
What is groundwater? 
The transfer of water through the ground back to the sea
What is infiltration? 
When water soaks into the soil
What is throughflow? 
When water soaks into the soil and seeps through it towards a river or the sea
What is percolation? 
The downward movement of water through the soil into a rock
What is interception? 
The process whereby precipitation is prevented from falling onto the ground by plants.
It slows run-off and reduces the risks of flash flooding
What is traction? 
Large rocks and boulders rolled along the bed of a river
What is saltation? 
when smaller stones are bounced along the bed of a river in a leapfrogging motion
What is suspension? 
Fine material light enough in weight to be carried by the river.
This material discolours the water.
What is solution? 
Dissolved material transported by the river
What is attrition? 
Material is moved along the bed of a river, collides with other material and breaks up into smaller pieces
What is corrasion/abrasion? 
Fine material rubs against the river back (sandpapering motion)
What is corrosion/solution? 
Rocks forming the banks and bed of a river are dissolved by acids in the water
What is hydraulic action?
The sheer force of water hitting the banks of the river
How is a waterfall formed? 
A waterfall is formed when a layer of hard rock lies on top of a layer of soft rock.
As the river passes over the hard rock, the soft rock below is eroded more quickly than the hard rock so the is a steep
Eventually this becomes deeper causing a waterfall
How is a waterfall formed? (Step 2)
The drop gets steeper and the river erodes the soft rock by abrasion and hydraulic action. This causes a plunge pool at the base of a waterfall.
How is a waterfall formed? (step 3)
The erosion gradually undercuts the hard rock and eventually, the unsupported overhanging rock collapses in the plunge pool. A steep-sided, groge is formed as the waterfall gradually retreats upstream.