Rivers Flashcards
Types of weathering
- chemical
- biological
- mechanical
Types of mass movement
- slumping
- sliding
Where does erosion take place in a river?
Types of erosion?
Upper and middle course
- attrition
- abrasion
- hydraulic action
- solution
Types of transportation
- solution
- suspension
- saltation
- traction
Reasons why rivers lose velocity and drop material
- increased amount of sediment in channel
- rivers mouth reached
- reduced volume of water in channel
- water becomes shallower
River landforms caused by erosion
-Waterfalls and gorges
- waterfalls and gorges
1. the softer rock starts to erode, forming a step or notch, creating a river rapid
2. the softer rock continues to erode whereas the harder rock is left sticking out. the height of the drop increases forming a waterfall
3. the softer rock starts to be eroded underneath the hard rock, the overhang of harder rock collapses and the waterfall now has a plunge pool
4. over time a gorge may form
Upper course of the river
Valleys are steep and V-shaped due to erosion
Here you also find interlocking spurs
River landforms caused by erosion
- waterfalls and gorges
- interlocking spurs
River landforms caused by deposition
- floodplains
- leeves
- meanders
- ox bow lakes
River landforms caused by deposition
-Floodplains
Are wide valley floors that surround river in the lower course.
Long profile of a river
Gradient of river from source to mouth increases
Volume and velocity of water increases as you go down stream
Cross profile of a river
Narrow—–wider
Due to erosion and river management
River landforms caused by erosion
-Meanders
erosion at the outside of a bend
deposition at the inside of the bend
River landforms caused by erosion
-Ox bow lakes
As meanders move the necks may end up close to each other and join up
River landforms caused by deposition
-leeves
Raised riverbeds
