Coastal Management Flashcards
Swell
Movement of the sea in rolling waves that do not break.
Fetch
The distance travelled by waves across open water.
Swash
The rush of seawater up the beach after the breaking of a wave.
Backwash
The motion of receding waves.
Constructive Waves
Low energy waves.
They have a strong swash and a weaker backwash. This means sand is more likely to be deposited on the beach.
Destructive Waves
High energy waves.
Have a stronger backwash which means they are able to erode the beach and carry sand offshore.
Sand Dunes
What it is and how it’s formed
What it is: a ridge of sand
How it’s formed: wind
Spits
What it is
longshore drift that forms a ridge of sand that extends from land to open water
Tombolo
What it is and how it’s formed
What it is: sand that grows out from mainland and joins with an island
How it was formed: spit
Cave
What it is and how it’s formed
What it is: eroded rock
How it was formed: wave energy
Stack
What it is and how it’s formed
What it is: pillar of rocks
How it was formed: when rocks falls into the ocean
Headland
What it is and how it’s formed
What it is: narrow, high land coming out from a coastal cliff into the sea
How it was formed: from rocks
Coastal lagoon
What it is and how it’s formed
What it is: a swamp at the back of a beach
How it was formed: water gets pushed back into it then can’t escape because the buildup of sand
Bay
What it is and how it’s formed
What it is: broad, curved indentation in the coastline
How it was formed: erosion overtime
Beach
What it is and how it’s formed
What it is: sandy area on the zone known as a berm
How it was formed: waves deposit sand on the berm
Coastal Dune System
What it is and how it’s formed
What it is: Sand and gravel deposits within a marine beach. (Beach berms, frontal Dunes, dune ridges, back Dunes)
How it’s formed: deposited waves.
Erosional or depositional? • sand Dunes • spits • tombolo • cave • stack • headland • rock platform • coastal lagoon • bay • beach
- sand Dunes - depositional
- spits - depositional
- tombolo - depositional
- cave - erosional
- stack - erosional
- headland - erosional
- rock platform - erosional
- coastal lagoon - depositional
- bay - depositional
- beach - depositional
Tides
• development
• impact
Development: caused by the gravitational interaction between the Earth and the Moon.
Impact: flooding, development of coast swamps
Longshore drift
•How it works
• It’s impact on coastal areas
How it works: the wave direction approaches the beach at an angle, then gets washed back into the ocean according to gravity.
Effects in coastal areas: can break down sea walls
SHEEPT
S - social H - historical E - economic E - environmental P - political T - technological
Short term changes in coastal areas
Erosion, waves, high tide
Long term changes in coastal areas
Destruction of land, rise in sea levels
Importance of coastal environment
Protection to the land, recreational
Managing coastal areas
Grounds, rock and sea walls, boardwalks and signage
