Coast Flashcards
Describe the formation of bar and give an example
A spit may develop across the bay linking two headlands to form a bar. Bars are straighten coastlines and trap water in lagoons on the landward side. Example: Slapton Ley, Devon
Describe the formation of tombolo and give an example
Occurs when a spit continues to extend and reaches an island (an offshore island). Example: Cheri beach in Dorset links to isle of Portland to mainland
Describe formation of curate forelands and give an example
They are low lying triangular-shaped feature that extend from a shoreline formed from deposited sediment. Form when long shore drift occurs in two directions which sediment in and causes them to converge at the boundary of a sediment cell. Example: Dungerness, Kent
Formation of a spit and give an example
The prevailing wind and the maximum fetch causes material to be carried by LSD across the coastline. Many spits develop a hook or curved end due to either change in prevailing wind or wave refraction at the end of the spit.
Example: Poole Harbour
Describe formation of offshore bars (sand bars) and give an example
They are submerged ridges of sand or coarse sediment. They are created by waves that operate offshore from the coast. Destructive waves erode sand from the beach which removes sediment and deposits it offshore as bars. Example: Norfolk
Describe formation of shingle beach and sandy beach and give examples
Shingle beach:
More exposed beaches tend to be steeper and high energy waves remove the sediment leaving larger shingles behind. Example: Chesil beach
Sandy beach:
Formed in sheltered bay, low energy constructive waves to transport and deposit sediment to shore. Example: south shields
CASE STUDY: coastal recession in the River Nile Delta
Give three factors causing high rates of recession
.soft,unconsolidated sediment is easy to erode
.Agricultural practice can reduce natural vegetation barriers and quality of soil
.Damming upstream reduces seasonal flooding and sediment deposition in the delta
CASE STUDY: coastal recession in the River Nile Delta
Give Three effects
. Food shortages and potential to cause starvation as 60% of Egypt’s food supply is threatened
. Millions of homes are threatened to be lost
. Land is becoming less fertile due to increased salinity levels
CASE STUDY: coastal recession in the River Nile Delta
Give three management strategies
. Coastal defenses such as sea walls
. Adding soil and sand to land to keep it fertile and build up the delta
. Changing crop management - so having more tolerant crops closer to delta edge
. Reclaiming land lost to the desert by diverting seasonal flood water into canals and pumping stations
CASE STUDY: coastal recession in the River Nile Delta
Background of River Nile Delta
Found in the mouth of the River Nile
River Nile delta is home to 39 million people
Coastal recession have been 100 m per year in some places
CASE STUDY: Coastal flooding in Bangladesh (cyclone Bhola 1970)
Give the effects of coastal flooding
. 500000 people dead
. Spread of water Bourne diseases, increased rate of malnutrition
. Contamination of water supplies and rivers with salt from the sea
. 65% coastal industry destroyed
CASE STUDY: Coastal flooding in Bangladesh (cyclone Bhola 1970)
Name the human and physical factors
Human:
Removal of mangrove forest for agriculture
High population density and lack of coastal protection systems
Physical:
Low lying land
As it is triangular-shaped head of Bay of Bengal it is more prone to erosion
CASE STUDY: Coastal flooding in Bangladesh (cyclone Bhola 1970)
Management
. Early warning systems through the Red Cross
Building 2000 new storm shelters
Community education and developing evacuation plans
CASE STUDY: Coastal flooding in Bangladesh (cyclone Bhola 1970)
Challenges to management
Cyclone shelters left in poor condition reduces their usage
Lack of access to TV, radio and phones
CASE STUDY: Coastal flooding in uk Northern sea (1953 storm)
Human and physical risk factors
Human:
Lack of systems /knowledge
Sea defenses in uk were inadequate design for flooding at the time
Physical:
Extremely high winds in Scotland
Storm coincided with spring tides
CASE STUDY: Coastal flooding in uk Northern sea (1953 storm)
Effects
.326 people died
. 160000 acres of land were submerged in uk
. 24 000 homes in uk were damaged
CASE STUDY: Coastal flooding in uk Northern sea (1953 storm)
Responses
ST:
Emergency temporary shelters opened
Search and rescue were available but delayed due to lack of comms
Donations from Red Cross and abroad were distributed
LT
Warning sirens were put in place
Building new flood defenses
Submergent coastlines, formation and examples (2)
Rias:
ria is a drowned river valley - a section of river valley flooded by the sea, making it much wider than would be expected based on the river flowing into it. Type of estuarine. Example: Knightsbridge Devon
Fjords:
Glaciated valleys near the coast which have been drowned by the rising sea levels at the end of last glacial period.
Example: Hardanger, Norway
Emergent coastline,formation and examples (1)
Raised beach:
A relict beach now above high tide level. Example: isle of Arran, scotland
CASE STUDY: Holderness coastline
HORNSEA
Tourist feature and protecting sea wall from wave erosion and winter flooding
Holiday resort with a promenade
GROYNES- £5.2million
SEA WALL raised slightly
+ve:
Relatively low cost
Accepted visually
Locally effective
-ve:
Trapping of sand from mappleton
Maintenance is continual
Hold the Line is present
CASE STUDY: Holderness coastline
Mappleton
1991 almost £2 million spent on two rock groynes and rock revetment to protect mappleton and the B1242 coastal road (supported by EU funding)
-ve:
Starves sediment down holerness coast so more prone to erosion Great cowden
Hold the Line is present
CASE STUDY: Holderness coastline
Withernsea
Threats to promenade and holiday business and jobs. Sea front protected by groynes, concrete sea walls and rock armor and beach nourishment
+ve:
Calms the concerns of local residents , hotel business and saves seasonal jobs in the resort
-ve:
The rocks have reduced access to the beach and views are restricted and have limited the length of sea wall
Hold the line is present
CASE STUDY: Holderness coastline
Spurn head
Spit is still currently growing out at around 10 cm each year winter storms threaten it.
Officially bonded in 1995
No active intervention plan is present
