Rivers Flashcards
What features could mean that the river has a high risk of flooding?
- Heavy rain
- No trees
- Impermeable rocks
- Lots of surface runoff
- Frozen ground
What features could mean that the river has a low risk of flooding?
- Light rain
- Permeable rock
- Not much surface runoff
- Forest
- Dams
What are the four types of erosion?
- Attrition
- Solution
- Corrasion or Abration
- Hydraulic action
What is the highest waterfall in the UK located on the River Tee’s?
- High Force Waterfall
How is a waterfall formed
- Hard impermeable rock can’t be eroded
- The water erodes the soft permeable rock via corrosion and abrasion
- The hard rock is eventually undercut and it collapses into the plunge pool
- This moves the waterfall back upstream leaving behind a gauge
How are interlocking spurs formed?
- The river erodes the landscape in the upper course via corrosion and abrasion.
- It winds and bends to avoid areas of hard rock. This creates interlocking spurs
How are meanders formed?
- Erosion and deposition
What is the key term that is used for the cork screw motion in the outer bend of the in meanders?
- Helicordal flow
State the four methods of river transportation?
- Traction (rolling of boulders and pebbles along the river bed)
- Saltation (Particles bounce along river bed)
- Suspension (When fine particles are held in water while its moving)
- Deposition (Where material gets deposited)
How is a Levee formed?
- When the river overflows its banks, the velocity decreases and sediment is deposited
- Coarser sands are dropped closer to the river and finer silts are carried further.
- Over the years, Levee are raised
How is a floodplain formed?
- When a river floods, it deposits silt
- Layers of silt build up to provide a thick layer of fertile alluvium
- This makes the land perfect for farming
State some hard engineering techniques and some postive and negative things about them?
- Dams and Reservoirs: Positive/ Lots of power produced, controls flooding. Negative/ Expensive, Causes landslides
- Straighening meanders: Positive/ Shorter distance, Ships can get through. Negative/ Less capacity in river, Unatural, Expensive.
- Embankments: Positive/ Holds more water, looks ok. Neagtive/ Expensive, Unsustainable
State some soft engineering techniques and some postive and negative things about them?
- Flood warnings and preparation: Positive/ Gives people knowledge that a flood is coming, good for wildlife. Negative/ Not always accurate, floods happen quickly.
- Floodplain zoning: Postive/ Looks natural, good for wildlife. Negative/ Limited places you can build
How much of the UK is moorland enviroment?
- 1/4 of the enviroment in the UK is moorland
What was one of the most important ports in the industrial revolution located on the river Tee’s?
Stockton
What did they use to make Stockton more assecible and why?
- There were to many meanders between Stockton and the sea
- This prevented big ships from getting through
- As the victorians wern’t enviromentaly freindly, they used meander straightning to create a 3km artificial line from Stockton to the sea.
What are some landforms you would find in the upper course of a river?
- Large angular bedload
- Lots of abrasion
- Interlocking spurs
- V-shaped valleys
- Waterfalls
What are some landforms you would find in the middle course of a river?
- Meanders
- Ox-box lakes
- Farmland
- Levees
- Floodplains
- Smoother and smaller bedload
What are some landforms you would find in the lower course of a river?
- Silt and fine particles in bedload
- Farmland
- Industry (shipping)
- Seal Sands (on Tee’s) based on estuary and has been reclaimed
- Estuary (where it gets tidal)
What two things change the cross profile of a river?
- Verticle erosion
- Lateral erosion
Where does deposition occur in rivers?
- Inside of bend
What are the three courses of a river?
- Upper course
- Middle course
- Lower course
Define Traction
- Large particles like boulders are pushed along the river bed by the force of the water
Define suspension
- Small particles like silt and clay are carried along by the water
