Coasts and Rivers Flashcards
(20 cards)
four main coastal erosion processes
Hydraulic action, abrasion, attrition and solution
how is a spit formed
longshore drift transports sediment: it builds up when the coast changes direction forming a spit, it curves due to wind and waves
what is a wave cut platform
flat area left behind as cliff retreats due to erosion at the base
example of UK coastal management scheme
Lyme Regis: sea walls, rock armour to protect erosion and landslides
What is beach nourishment is it hard or soft engineering
adding sands to beaches to absorb wave energy, soft engineering
difference between constructive and destructive waves
Constructive: strong swash, builds beaches
Destructive: strong backwash, erodes beaches
what are groynes and what do they do
wooden or stone fences that trap sediment to reduce longshore drift
what is a managed retreat
allowing low-lying land to flood naturally, forming salt marshes and reducing flood risk
3 main flooding erosions
- hydraulic action
- abrasion
- attrition
what is vertical and lateral erosion
vertical erosion deepens the river valley, lateral erosion widens the river valley.
how is a meander formed
water flows faster on the outside bend creating more erosion, water moves slower on the inside (deposition), creates a looped bend
How does an oxbow lake form
a meander neck is cut through during a flood, leaving a cresent shaped oxbow lake
What is a floodplain
flat land near a river that floods formed by deposition during floods over time
2 soft engineering strategies for river management
Afforestation, floodplain zoning
2 hard engineering strategies for river management
Dams and reservoirs, channel straightening
why was banbury flood management scheme needed.
Banbury experienced floods in 1998 and 2007, caused damages to homes, business and transport
main feature of the banbury flood management defence scheme
2.9km earth embankment was built to create a flood storage area capable of 3 million cubic metres of water
how does the banbury flood management scheme help defend the town
the embankment stores excess water from rainfall, reducing river discharge , prevents river from overflowing
social benefits of the banbury flood management scheme
400 homes and 70 businesses protected
economic and environmental benefits of the banbury flood management scheme
18 million dollars for the scheme, prevents flood damage, improved biodiversity with habitats like ponds and trees
