Rivers Flashcards
What is a tributary
Small streams that join a river
What is a watershed
High ground between 2 drainage basins
What are levees
Raised banks formed by the river on its floodplain
What is a confluence
The meeting point between 2 rivers
What are floodplains
Land that is covered in water in times of heavy rain
What are meanders
Bends in a river
What are estuaries
Near the sea the part of the river that is affected by the tides
What is the mouth
The placed where the river reaches the sea
This is the end of the rivers course
What is a feature (landform)
A natural, physical part of the Earth’s surface e.g. volcano, cave, waterfall
What are the 4 processes of river erosion
- Hydraulic action
- Abrasion
- Solution
- Attrition
What is hydraulic action
Is the force of fast-flowing water that breaks up the bed and banks of the river
Almost like a power hose
What is abrasion
Stones carried by the river (load) hit against the bed and banks of the river, wearing it away
What is solution
When the river water dissolves the rocks over which it flows
What is attrition
When stones roll along the bed or collide with each other. River stones become round and smooth over time
What are the 4 processes of river transportation
- Suspension
- Solution
- Traction
- Saltation
Why does a river deposit its load
- The river loses its speed and energy, because the gradient (slope) is almost flat
- Its volume decreases in the summer due to evaporation
- River deposition is useful because river mud, called alluvium, is a fertile soil. This helps farmers by making their fields more fertile
What is the river load
This is all the material a river transports e.g. rocks, pebbles, silt, sand, mud and clay
What are the stages of a river
- Youthful stage
- Mature stage
- Old stage
Name 3 features of the youthful stage
V-shaped valley
Interlocking spurs
Waterfall
Name the process in the youthful stage of a river
Erosion
Name 2 features in the mature stage
- Meanders
- Ox-bow lakes
Name the processes in the mature stage of a river
Erosion and deposition
Name 3 features in the old stage of a river
- Levees
- Floodplain
- Delta
Name the process in the old stage of a river
Deposition
Name the 3 stages of floodplains
- Deposition of sediment
- Gradual build up
- Fine sediments settle further away
What are artificial levees
They are built by humans using soil, concrete or other materials to control flooding and protect settlement
Name the 6 reasons why people interact with rivers
- H.E.P. (Hydroelectric power)
- Transport
- Sport and recreation
- Irrigation
- Water supply
- Fertile floodplain
Name 2 positive impacts of dams
- H.E.P. Generation
- Water supply and irrigation
Name 2 negative impacts of dams
- Displacement
- Environmental damage
Name 4 reasons why flooding has increased recently
- Population growth
- Building on floodplains
- Clearing trees for houses
- Heavier rainfall due to climate change
Name 3 reasons on how to reduce flooding
- Dredge slit from the bed of the rivers
- Don’t build on floodplains
- Reforestation (plant more trees)
