Coastal Environments Flashcards
Backshore?
This is the area between the high water mark and the landward limit of marine activity.
Foreshore?
This is the area lying between the high water mark and the low water mark and is often seen as the most important area for marine activity.
Inshore?
The area between the low water mark and the point where the waves cease to have any influence on the land around them.
Offshore?
The area beyond the point where waves cease to impact the seabed and in which activity is limited to the deposition of sediments.
Inputs?
- Energy (waves, wind, tides and currents)
- Sediment
- Biogenic inputs
- Changes in sea level
- Human activities
Processes?
- Erosion
- Longshore drift
- Deposition
Outputs?
- Erosional landforms
- Depositional landforms
- Accumulations of sediment above tidal limit
- Loss of wave energy
Creation of waves?
Friction between the wind and surface of water causing disturbance creating waves.
Characteristics of constructive waves?
- Strong swash
- Weak backwash
- Generate in open ocean
- Low and long
- Low frequency (6-7 waves per minute)
- Gentle beach
Characteristics of destructive waves?
- Weak swash
- Strong backwash
- Local storms are responsible for them
- High and steep
- High frequency (10-14 waves per minute)
- Steep beach
Factors affecting wave strength?
- Wind strength
- Fetch
- Duration of the wind
- Water depth
Spring tide?
When Moon is between the Earth and the Sun, creating the highest high tide due to combined gravitational pull.
Neap tide?
When the Earth, Moon and the Sun for a right angle creating the lowest high tide as the gravitational pull of the planets interfere.
Four options for coastal management
Hold the line
Advance the line
Do nothing
Retreat the line
Four options for coastal management
Hold the line
Advance the line
Do nothing
Retreat the line
