Landforms in lower course Flashcards
What characterizes the lower course of a river?
High volume and large discharge
The river channel is deep and wide, and the surrounding landscape is flat.
What happens to a river as it reaches the end of its journey?
Energy levels are low and deposition takes place.
Where are deltas typically found?
At the mouth of large rivers.
What is a delta?
A landform created when a river deposits its material faster than the sea can remove it.
What are the three main types of delta?
- Arcuate or fan-shaped
- Cuspate
- Bird’s foot
Describe an arcuate delta.
Land around the river mouth arches out into the sea, creating a fan effect.
Describe a cuspate delta.
Land around the mouth of the river juts out arrow-like into the sea.
Describe a bird’s foot delta.
The river splits and each part juts out into the sea, resembling a bird’s foot.
What is the role of waves in the formation of a cuspate delta?
Waves carry sediments away from the coast.
What should a labeled diagram of a delta include?
- Distributaries
- Shape of delta
- Flatland
- Sea
- Fertile soil
What type of load does the lower course of a slow-moving river carry?
Fine silt as suspension load.
What happens to the river’s speed as it enters the sea?
The speed reduces and deposition takes place.
What creates the bottom-set beds and top-set beds during deposition?
The heaviest sediment is dropped first, and the lightest last.
What process helps the deposition of fine sediment in a delta?
Flocculation.
What happens to fine clay particles during flocculation?
They stick together and become heavier, dropping to the sea bed.
