Hard and soft engineering Flashcards
How does beach nourishment and re-profiling work?
Addition of sand or pebbles to an existing beach to make it wider - is usually dredged from nearby seabed
What are the advantages of beach nourishment and re-profiling?
Cheap
Easy to maintain
Looks natural and blends with existing beach
Increases tourist potential by creating bigger beach
What are the disadvantages of beach nourishment and re-profiling?
Needs constant maintenance because of the natural processes of erosion and longshore drift
What is the cost of beach nourishment and re-profiling?
£300,000/100m
What is an example of beach nourishment and replenishment?
Bournemouth beach
What is cliff regrading and drainage?
Reduces the angle of the cliff to help stabilise it. Drainage removes water to prevent landslides and slumping
What are the advantages of cliff regrading and drainage?
Effective on clay or loose
How long is a Holderness coast?
50km
What makes Holderness coast the most rapidly eroding coastline in Europe?
Combination of clay geology and a high energy environment
What landforms are along the Holderness coast?
Flamborough Head
Holderness Cliffs
Spurn Head
What is Flamborough Head?
A class arch, stack and wave-cut platform - caused by wave quarrying
What are the Holderness cliffs?
Cliffs formed by material left by ice sheets
How fast are the Holderness cliffs retreating at?
1.8m per year
What erosion takes place on the Holderness Cliffs?
Rainwater enters clay and the weight of the water causes material to slide seawards
What is Spurn Head?
Sediment is deposited creating a fragile recurved spit
How fast does Spurn Head spit grow?
10cm a year
What are the physical factors that affect the Holderness Coast?
Weather
Waves
Geology
How does weather affect the Holderness coast?
Winter storms produce stronger waves and higher sea levels. This leads to increased erosion - saturated cliffs leads to slumping
How does waves affect the Holderness coast?
Dominant waves are from the North-East. Destructive waves erode beaches and attack the foot of the cliff
How does Geology affect the Holderness coast?
Two main types of rock found are chalk and boulder clay. Boulder clay easily erode
What management is along the Holderness coast?
Sea wall
Gabions
Rip-rap
Beach nourishment
Do nothing
What sea wall is located along the Holderness coast?
Situated at high value areas at Hornsea and Withernsea
What Gabions are located along the Holderness coast?
The wire cages holding small rocks are located at Skipsea
What rip-rap is located along the Holderness coast?
Large rocks in front of sea walls/cliffs to absorb waves like Easington
Where is beach nourishment located along the Holderness coast?
Hornsea and Mappleton
Where are they ‘Doing Nothing’ along the Holderness coast?
Neck of Spurn he’d as its growing so fast
Where is the Holderness Coast?
East Coast of England
Where is Christchurch Bay?
Dorset and part of Hampshire on South Coast
What is Christchurch between?
Hengistbury Head and Hurst Castle Spit
What coastal processes take place on Christchurch Bay?
Littoral drift brings sediment onto Bournemouth Coast - some gets deposited onto Hengisbury Head, some leaks round to Hurst Castle spit
What coastal processes specifically take place on Barton-on-sea?
Marine processes - hydraulic action and abrasion
Sub-aerial processes - slumping and rock fall
Geology - impermeable land lies under permeable land causing land slides
What coastal management in on Hengistbury head (affluent)?
Long Groyne - 215m long, disguised by rock to give a natural look
Rip-rap
10 rubbles groins on east coast
What coastal management is on Barton-on-sea? (less affluent)
Cliffs have been regraded to improve stability
Slumping and rock fall acts as a natural barrier
How quickly does Christchurch Bay erode per year without management?
1-2m
What other area is affluent on Christchurch Bay that isn’t Hengistbury head?
Milford-on-sea
What management is on Milford on sea?
Sea wall
Wooden groynes
What is the main aim of the Odisha ICZM?
Promote sustainable use of natural resources while maintaining the natural environment
Protect environment
Establish sustainable levels of economic and social activity
Who are the main organisations involved in Odisha’s ICZM?
Ministry of forest and environment
Indian government
The World Bank
What are the issues identifies by the ICZM?
Coastal erosion Assessing vulnerability to disaster Biodiversity conservation Livelihood security Pollution and environmental quality management
How have people adapted to the risks of coastal erosion and tropical storms in Odisha?
Provided relief supplies
Broadcasted warning
Conducted stages evacuations
How has the ICZM helped mitigate against coastal erosion and tropical storms?
Mangroves
Where is the Odisha coast?
South-East Coast of India
How long is the Odisha coast?
480km long
How big is India’s population?
46 million
How many deltas does the Odisha coastline have?
6 - hence the name of Hexadeltaic region
How big is the mangrove forest on the Odisha coast?
1435km2
What is the salty lagoon called on the Odisha coast?
Chilika Lake
How can you see Odisha coastline as a system?
Six major rivers feed sediment into the system
Chilika Lake is an important store
What are the main opportunities for humans development on the Odisha coast?
Tourism
Jobs in coastal fishing, aquaculture, offshore oil mining,
35% of coastline is laden with substantial sediment minerals and heavy metal deposits
Huge potential for wind, tidal and wave power
Large stock of marine animals
How much of Odisha’s coastline is laden with substantial sediment minerals and heavy metal deposits?
35%
What animals is there a large stock own the Odisha coast?
Fish Marine mammals Reptiles Olive Ridley Turtle Seagrass meadows
What are the main risks for human development and occupation in Odisha?
Majority of the state live on coastal plain
As ITCZ moves north in the Summer it brings storms
Accretiom occurs driving general summer conditions where there are low-energy waves and erosion in winter with high-energy waves
What are the shoreline management policy options?
Hold the line
Managed realignment
No active intervention
Advance the line
What is holding the line?
Maintain or upgrade the level of protection provided by defences or natural coastline
What is managed realignment?
Manage the coastal processes to realign the ‘natural’ coastline configuration, either seaward or landward, in order to create a future sustainable shoreline position.
What is no active intervention?
A decision not to invest in providing or maintaining defences or natural coastline.
What is advance the line?
Build new defences seaward of the existing defence line where significant land reclamation is considered.
How many SMP’s are there across England?
22
What management is being done at Hurst Spit?
Hold the line
How are they holding the line at Hurst Spit?
Maintaining revetments
What management policy is being done at Milford on sea?
Holding the line
How are they holding the line at Milford on sea?
Maintaining beach defences
What management is being done at Barton-on-sea?
Stabilise cliff
Cliff drainage
What management policy is being done at Durlston Head?
No active intervention
What is the aim of SMP’s?
To identify the most sustainable approach to managing the flood and coastal erosion risks to the coastline
What do SMP’s aim to plan for?
Short term (0-20 years) Medium term (20-50 years) Long term (50-100 years)
What are the key features of SMP’s?
Provide assessment and framework of risk
Address risks sustainably
Provide plan for coastal defence
Promote long-term polices
Be environmentally, socially and economically sustainable
Ensure plans comply with international legislation
