Paper 1 - River Landscapes and Processes Flashcards
What is the Watershed?
The outline of the Drainage Basin
What is the Drainage Basin?
The area over which a river covers
What is the River Source?
Where the river begins, or comes from
What is a Confluence?
Where two rivers are stream join to create a wider channel
What is a Tributary?
Where a smaller river or stream joins the bigger, man channel
What is the River Mouth?
Where the river meets the sea
Why does a river’s velocity increase as it travels dowstream?
- There is change in gradient
- More water from confluences/tributaries
- Less friction of the river bed due to erosion
Why does gradient decrease as the river travels downstream?
- Not enough water at the source to have the power to erode the river bed
- As confluences/tributaries join, discharge increases
- River gains power and can now erose the river bed to a flatter gradient
What happens to load quantity and why?
- More load in the river
- More water due the confluences/tributaries
- Brings more sediment
- Has more velocity so has enough energy to pick up more load
What happens to load size? And why?
- Load gets smaller
- River has more power from more water
- Attrition can occur
What is Weathering?
The breakdown and decay of rock by natural processes
What is Erosion?
When water wears away rock and soil
What is Transportation?
When a river picks up and carries material
What is Deposition?
When the water doesn’t have enough energy to carry it’s load, so ‘drops’ it
What is Mass movement? Why does it happen? What can speed it up?
- The movement of rocks and soil downslope
- Due to gravity
- Sped up by weaker rocks and steep slopes
What are the three types of mass movement?
- Soil Creep
- Sliding
- Flows
What is Soil Creep?
Individual particles of soil move slowly down the slope due to gravity
What is Sliding?
The material moves rapidly down the slope in one go
What is Flow?
When the soil and rock is mixed with water and flows like a liquid downhill
Name three types of weathering
- Biological
- Chemical
- Mechanical
Name 4 types of erosion
- Hydraulic action
- Abrasion
- Attrition
- Solution
What is mechanical weathering also known as?
Freeze-thaw weathering
What is chemical weathering also known as?
Acid rain
Describe mechanical weathering
- Cracks in rock get filled with water
- Temperature falls below 0°C and water freezes and expands forcing the crack open
- Ice melts when temperature returns to above 0°C and runs away
- Process repeats over time and cracks became wider until the rock breaks up completely