River Flashcards
(22 cards)
What does source mean
Where river begins starts from mountain tops
What does course mean?
Where river takes to sea.
What is it when two or more streams join together ?
Confluence
What does tributary mean?
It means when smaller river flows in a larger river
What is a mouth
Where a river usually ends
What is a watershed ?
Area of high ground which separates two drainage basins
What is an estuary ?
Part of a river or mouth that is tidal
What are the processes of river erosion?
Hydraulic action: force of fast flowing water that breaks up bed and banks of a river.
Abrasion: stones carries by a river, hits against bed and banks of a river, wearing it away
Attrition: stones roll along bed or collide with each other. They become smooth and round overtime.
Solution: river water dissolved the rock
What is the process of river transport?
Traction: larger stones are rolled or dragged along the river bed
Saltation: lighter stones are happened along the river bed.
Suspension: smallest rock or soil grains are held up in the water, making it cloudy
Solution: rock is dissolved in water. Water may be clear but coloured.
What causes the river deposition process?
When a river meets the sea or lake.
When a river meets an obstacle such as dams or boulders
How is river deposition useful?
The river mud called alluvium is fertile soil.
Name three features of the youthful stage:
V shape valley, interlocking spurs, and waterfall
Name the three features of an old stage :
Levees, floodplain, delta
Name the two features for mature stage
Meanders and oxbow lakes.
What are levees?
Long bank of stones and alluvium that forms beside a river
How do levees form ?
- When river floods, it spills over onto the floodplain
- Deposition is one of the heaviest stones happens immediately because river lost energy. Stones dropped onto the bank, right beside the river channel
- Stones build up over many floods to form raised banks called levees.
- Finer particles are carried out over floodplain and deposited as alluvium,
- People often build artificial levees to protect farms and cities, but rivers can break though during powerful floods
How do we interact with rivers?
- sports and recreation: river area used for activities such as fishing and swimming.
- transport: many people travel and carry goods
- water supply: provides fresh water for our everyday lives
What are the positive impacts on dams ?
HEP generation: provides renewable electricity, reducing fossils fuel reliance.
Water supply: ensure stable water access, for drinking farming and industry
What are the negative impacts of dams?
Displacement: flooding forces communities to relocate.
Environmental damage: alters eco system, disrupts fish migration, causes erosion.
Why has flooding increased recently?
Population growth: more people living in towns built along rivers
Building on floodplain: county council have allowed constructive of housing estates on floodplains
Cleaning the trees and farmland
How do we reduce flooding
Dredge silt from the bed
