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Changes Caused by Human Activity (Managemet: Studland Bay, Dorset…
Changes Caused by Human Activity
Managing Coastlines
Good management considers:
Environment, Physical, Residents, Other interest groups = Balanced Policy
Methods
Shoreline Management Plans
Examine risks associated with coastal practices
Policy is drawn up by a variety of stake holders
Present a policy to manage the risks
Bais cunit of management is the sed. cell
The SMP of an area will:
Divide sub-cells in appropriate management units
Identity economic + environmental assets, assess issues + conflicts + propose a defence plan
Use DEFRA criteria for management
ICZM
Manages the whole coastal zone
Habitat destruction + biodiversity
Pollution
Loss of fish stock
Economic decline + social deprivation
Began in 1996 by the EU
Some authorities have set up ICZM in conjunction with SMPs
ICZM + SMPs
Coast Benefit Analysis (CBA) + an Environmental Impact Assessment (EIA) are carried out
CBA - evaluates the economic-social + environmental costs + benefits of a scheme
EIA - assessing the impact of a project so damage can be minimalised
DEFRA Criteria
Hold the line - maintain existing defences
Advance the line - build new defences
Managed retreat/realignment - allow flooding with monitoring
No active intervention - no investment
Management: Sandbanks Peninsula + Poole Harbour
Need for Management
Loss of high value commercial properties e.g. Sndbanks hotel
Significant employment + generates spending in local economy
High demand for residential prices + very expensive
4th most expensive in world
Luxury apartments over £2million
Beach is a major tourist attraction
Blue Flag award for water quality
Provides protection from waves for Poole Harbour
Safe for water sports
Harbour has many yacht clubs
Entrance to harbour is used by cross-channel ferries + commercial ships
LSD could cause entrance to become shallow
Climate change = s.l. rise - 0.6m in next 10 years
Flooding properties
Cutting off beach peninsula from mainland
Estimated £18 million in damage to local residential properties in next 10 years if no strategies are put in place
Management Methods
Rock Groynes
Prevents sed. being moved
Restricts sed. from entering the harbour entrance = free for shipping
Absorbs wave energy = reduced erosion rates
Maintains a deep + wide beach
Beach Recharge + Dredging
Conserves beaches
Sand dredged from offshore is sprayed onto beach - expensive (£20/m3)
Depositing sed. dredged from harbour just offshore- cheaper (£3/m3)
3.5 million m3 of sand added to Poole Bay beaches
Managemet: Studland Bay, Dorset
Background
5km sand peninsula
Near Poole Harbour
Honeypot site
25,000 visitors/day in summer
Income from tourism helps with conservation + pays for damage that tourists cause
Inland freshwater lake behind
Heathland - many reptile species
Fragile environment
Different beach uses = conflicts
If the area gets ICZM status, conservation measures will be forced
Challenges
Litter - 45,000 tonnes on a busy weekenf
Bins have to be constantly emptied
Cleaning is time-consuming
National Trust has to pay to dispose each kg of litter - this is the greatest cost
Boat users
Throw litter into sea
Damages sea grass meadows
Achors scour the bed = bare patches of sand
Sand is so fine that it is easily eroded
Fires
2010 fire destroyed 10 hectares
Erosion
Don't know whether to advance the line/manage retreat
S end of peninsula is eroded
Norther end is gaining 1.5m/year
Difficult to predict how long before facilities are under attack
300 beach huts - major revenue
Dunes were created to protect the huts
Huts have been moved back as the sea has continued to erode the area - the huts are nearly at the car park now
Future ideas to put them on stils
Solutions
Zoning solves conflict between users
No boating areas = safe for swimmers
Horse riding restricted thruout the year
BBQ not allowed on sand dunes - specific BBQ areas
Fencing prevents people entering the dunes
Reduces dune erosion
When deciding to move fences, they look for sea lime among marram grass
Sea lime is the first coloniser and its presence shows that the dune is under stress - is bc of heavy footfall
Board walks
For the disabled
Keep sand in place - reduces erosion
Time-consuming
Voluntary anchor zone to reduce effect of boat anchors on sea grass
To reduce erosion:
Gabions at the end of the S beach
Cliffs there are made from clay
Protects cafes + facilities behind
Stone lasts longer than wire, so sections need to be rewired - expensive to maintain
Current strategy is managed retreat
Will roll back buildings when necessary
Economic
Tourism
300 people depend on its tourism ind.
25,000 visitors each day in summer
300 beach huts
Major revenue source
240 are privately owned
£890 for a year's rent
People buy food + such form local shops
= National Trust is important employer
Employs 56 people full-time + 126 in summer
Has many tenants running their own businesses
Stables + riding, + canoeing
Location + Transport
Ferry access points
Accessible from London
90% of people travel by car
Train station is 1hr away by public tranport
4 different car parks
Filled by 11am + clogged roads
Oil Industry
Has Europe's largest oil field
15,000 barrels/oil/day
Employs 400 people in Dorset
Will be gone within 20 years
Designed so that environmental impact was minimised
Plant was locate din the trees so that it was hidden
Colours are green/brown - camouflaged
Some tanks are semi-buried in ground
Don't use steam
Oil company will have to restore landscape after
Environmental
Sea grass meadows
Attractive to divers
Breeding ground for seahorses
Other native organisms there
Attractive for marine bioligists
Damaged by anchors from boats
Heathland
6 species of reptiles - most in the country
Many plant species
Resting place for 5,000 birds in winter
Destroyed by fires - often caused by BBQs
Economic Development: West Bay, Dorset
Background
Coastlines provide:
Attractive environments for tourism
Access to sea for trade, transpoty + fishin
Taking advantage of oppos. can lead to unintentional change within the landscape
Management may be required to mitigate the impacts of human use
West Bay Development Scheme
230m replacement West Pier
Rock armour protection on seaward side
Shelter the harbour
Realignement of the Pier will decrease the wave disturbance between the Piers + create a calmer harbour
Will protect the W end of E beach against SW storm + protect W beach from SE storms
Realigned of W pier will increase number of days the harbour entracec can be safely navigated
Demolition of existing W Pier
New slipway area + 10m wide slipway using amts. from demolished section of W Pier
Rock armour to protect W Cliff sea wall
Beach replenishment of W Beach
Gravel to reduce overtopping + protect sea wall
Increase size fo beach
Dubai: Development Issues
Background
Has developed into one of the world's premier tourist destinations
Is that capital of the 7 emirates that comprise the UAE
Located on a natural creek that runs inland for 10km, on the southern shores of the Arabian Gulf
Is one of the world's fastest-growing tourist destinations
Visitor numbers increased from 1 million in 1990 to over 6m in 2004
Economic History
Economy prospered after 1894 - tax exemption given to foreign traders
Main exports were shells, pearls + gold until 1966 when oil was found
Oil production peaked in 1991 at 410,00 barrels/day
Oil reserves are predicted to dry in the next few years = shift in economy to tourism + business
2001 - foreign nationals were allowed for the first time to buy property
Since, over 120,000 British people have moved to Dubai
Constitutional Monarchy
The Al Maktoum family controls the wealth of the country + diverts money to the sovereign wealth funds
Government-owned investment companies
New Investment
Qatar, UAE + Bahrain have invested heavily in moves to develop global connections + enter the knowledge economy
Trade + info. exchange are crucial to this diversification
Jebel Ali is the 2nd largest man-made port in the world + 8th largest in container traffic volume
Free Trade Zones
Attracted large TNCs
Problems
Immigration
Population has more than doubled in last 15 years - now 1.4 million
Migrants outnumber Emirates 8:1
Conditions in labour camps are poor
Global financial crisis = much unemployment
Bc construction projects were halted
Small Gulf states are significant labour importers - initially for oil + gas but more recently in:
Construction + property development, education, retail, finance + tourism
Effects
Large percentage of pop. are foreign-born
Cross-town journey now takes over 1 hour compared to 15 mins
Response
: the 89km Dubai Metro Light railway should relieve congestion when complete
Cultural conflicts
Sharia-based law states that alcohol consumption, homosexuality + infidelity are forbidden
Their laws do not sit well with the thriving tourist industry + 230 British people that have been imprisoned
Inequalities
Some of the largest gender inequalities in the world bc most immigrant workers are male
Immigrant workers do not have voting rights
Poor living conds. + low wages for the hundreds of thousands of temp.Asian construction workers
Conditions for expat property developers + TNC workers are very good
Environment
Water
Bc of its arid climate, water scarcity is rising as pop. + ind. expands
Filling the gap demands huge investment in desalination plants - very. energy-intensive + expensive
Energy
Tourist developments+ air-conditioned buildings = loss of power
Mostly oil-fuelled
Its 6 desalination plants are extremely energy-intensive
Produces more C emission per head than any other country
Coastal Environment
Huge coastal reclamation schemes = detrimental effects on marine life
Pressure for residential + hotel development = construction of artifical islands offshore
The World, The Palm Islands, The Waterfront
Pollution
Dust storms
Construction dust
Vehicular pollution
Tourism
Background
Many projects are underway to attract further visitors
Plans for entertainment complex as large as Birmingham
Longest strip hotel in the world
Several theme parks
Sport, music + shopping festivals
Dubai Shopping Festival attracted 4 million visitors in 2008
Effects
Positive
Relatively short natural coastline - 72km
Artificial islands increase the shoreline by over 400km
Palm Jumeirah has 16 fronds
Private beachside villas
Marinas
4000 properties bought on the island within 72 hours of the development
A rock crescent surrounding the 'palm' acts as a breakwater
In the centre is Dubai's largest hotel, the Atlantic
Over 1500 rooms + an aquarium
Before development of the islands began, there were several environmental assessments + water quality tests
Aimed to minimise environmental impact
Breakwaters provide a habitat for marine life
Marine biology lab. monitors activity in the coastal areas
Negative
Sand used to create islands is dredged from Persian Gulf + sprayed into place
Often buried coastal reefs + oyster beds in the process of spraying
Fall in local fish pops. bc of habitat degradation
Concerns fo the endangered sea turtle species, whose breeding grounds are being threatened
Sediment erosion + transportation thru LSD means the palms will need constant artificial sed. redistribution - expensive
Desert Tourism
Problems
Several companies offer excursions into the desert
In some areas this is entirely unregulated
Vehicles create channels for runoff = increased erosion rates
Locals ride over dunes on quad bikes
Damages the cryptobiotic crusts
Solutions
Community-based project - sustainable management
Many of the desert safaris include a visit to a Bendouin camp
Camel riding, purchase of traditional handcrafts, understanding of local culture
Dubai Desert Conservation Reserve
Popular tourist destination
225km square of desert
National Park status in 2004
Visitors are educate about the environment
Only 4 tour operators are permitted inside
Before - land was being degraded by overgrazing from camels + poor farming practises
Careful zoning + monitoring of certain areas = Arabian oryx and threatened gazelle species have been introduced
Conclusion
Some think its growth is not sustainable
Already reached its peak + many of its buildings will be unfinished
Dubai will invest any amount of money to ensure success
Marketing campaign attracted international interest
Coastal Reclamation Scheme
Background
3 artifical islands
Jumeriah, Jevel Ali + Deria
Creation of over 300 islands
Increased Dubai's shoreline by over 400km
Project Features
Range of 1st class hotels
Golden Mile retail destination
Over 200 retail outlets
860 residential unts
The Village Centre
Over 1000 apartments + townhouses
Marina
Shoreline Marina
400 berths for private vessels
Beachside villas on the fronds of the palm
Palm Jumeriah
Construction Process
Began in 2001
Sand was dredged from the seafloor and transported to the location
Rock was sourced from local quarries + brought to the sire on barges
Once the breakwater was in place, construction began
Rainbowing
(dredging + spraying sand) built the sand layer
94 million m3 of sand deposited
5.5 m m3 of rock used
Problems
Breakwater
Area withing the fronds was becoming stagnant
Breakwater was redesigned to have 2 openings to the sea - allowed water to circulate
Allowed water to be flushed out every 14 days
Water in the breakwater was not circulating ass expected
City Construction
Sand could not support the weight of the buildings = settlement + sinking
Duabi is near EQ fault zone
If an EQ occurred, the sand would undergo liquefaction = islands would sink
So sand undewent vibrocompaction
Vibrations from a probe rearrange the sand into a denser structure
Over 200,000 locations underwent this process
Monitoring
Has 2 beaches: Open Beach + Salient Beach separated by a T-shaped breakwater
Prior to construction, the beaches followed a linear form
The beaches rapidly responded to the construction of the offshore breakwaters
Northerly waves are removed from the nearshore regieme
= NE-directed transport rate has icnreased = coastline built-up rapidly
A large amount of sed. accumulated on Salient beach
4000 m3/year
Area N of Jumeriah has retreated by erosion
New harbour blocked sed. moving from SW
NE transport has eroded the beach
Changes in wave directions
Post-Construction Impacts
Palm Jumeriah
Despite the compaction + vibrocompaction, it's shrinking by 5mm
Erosion of island by wind + water
Nets, traps + filters are used to catch sed.
Nourishment required in some areas
Surrounding Areas
Prior to contraction, water + wave action transported mats. eastwards
Since construction, water flow has changed and water is required to flow around the island
Erosion + shoreline patterns will be modified
Ecosystems
Dredging processes has deposited silt in other clear areas, covering the following with 5cm of sed.:
Corals, oyster beds, sea grass
Developers insist that sea grass now grows between the fronds and break water is a new coral reef habitat
Artificial reefs are being constructed by sinking objects e.g. a jet airliner + London bus
ICZM
ICZM monitoring progreamme began in 1997
Wave rider buoys were set up to monitor nearshore wave action
Batyhmetry
Involved surveys of the 500m wide strip of coast
Data was collected along profiles usign GPS + echo sounding
Topographic surveys
Scatter profiles - collected spot heights to contour the beaches
Coastline divided into units for monitoring
Monitoring Methods
Nearshore Wave Measurements
Direction wave info. collected
Instruments measure the water column using echo sounds
Pressure censors record water depth
Video Monitoring
Cameras monitor coastline changes
Meterological Data
Wind speed + dir., s.l. temps., barometric pressure
Meterological station on Jumeriah Open Beach
Sediment Sampling
Grain size + fall velocity
Provides inputs to the coastal evolution, sed. transport + topographic mapping
Coastal Erosion
Problems
Beaches need 300 lorry loads of sand each year
Use of offshore dredging in the construction of the islands = increased wave heights = increased erosion in adjoining stretches of coastline
Dubai Beach Protection Scheme
Covers a 3.5km stretch
Severe erosion as a result of the offshore developments = safety of buildings under threat + hindered development of beaches
Groynes
Slow down LSD
5
Timber + steel
Beach Replenishment
Covering 760,000 m3
Work will be carried out in stages to avoid complete closure of the beaches
Environmental Impacts
Negative
Retreat is damaging coral reefs
Devastation local fish stocks - these support endangered sea birds
Destroys the sea bed
Positive
Resorts will provide new homes for local sea life
Artificial reefs built to attract coral + fish
Management
Environmental team of 20 international environmental institutions to ensure preservation + sustainability
Water quality studies
To ensure water circulation characteristics would be maintained after the development was complete
New sewage treatment plants + curved breakwaters provide habitat for marine life
Flood Protection: Chiswell, Portland Island, Dorset
Background
Chesil beach is the main protection for Portland + Weymouth
Prevailing SW winds + heavy swell originate from the S Atlantic - fetch over 6000 km
Large storms attack Chesil beach + water sometimes eprcolates through
Percolation flooding is the most common type at Chiswell
Storms of 1978-79
Background
Huge waves swept over Chesil Beach at Portland
Town was cut off from the mainland for 3 days
Fishing community at Chiswell was devastated
Another storm occurred 3 months later
Flood Characteristics
December Floods
Steep waves + 12 second perios
Strong onshroe winds
Plunging waves - steep backwash
Beach crest level lowered
Overtopping water eroded landward face
High risk of breach
February Floods
Caused by ocean-swell of 18 sec. period waves
Sudden arrival - no strong winds
These swell waves = much higher surge conds.
Long-period waves that carried mats. landward rather than seaward
When the seas subsided, the beach was left in a stable condition
Unlikely for breach to occur under wave-attack of this type
Flood Protection
Since late 80s, £4.5 million has been spent on a flodd alleviation scheme for Chiswell
Sea defences:
Gabions - filled with pebbles from the beach
Gabion mattresses on top of the beach limits amount of mat. moved from + over the top of the beach
Intercepting drain - takes water coming over + thru the beach
Water is channeled away from residential properties + the road into Portland Harbour
Bc of long-standing flood problems:
Housing development have openings between buildings to allow water to pass thru
Houses that were once at the back of the beach have been replaced by the sea wall
Borough Council establishes where new developments can occur
Economic Development: Mangawhai-Pakiri Coastline, NZ
Economic Development
Sand is essential mineral resource
Construction, glass m.f. + beach replenishment
Nearshore zone of M-P = HQ sand resource
Suitable for construction
Only 50km N of Auckland
1/3 of NZ's pop. + growing rapidly
Tourism centreed on its coastal amenities is growing - record 2.3 million visitors, 2015
Offshore Mining + Sed. Budget
70 years of nearshore dredging on the 20km coasstline
Mining ended at Mangawhai in 2005 but continues at Pakiri
Currents rates are 75,000 km3/year until 2020
Large proportion of sand used to replenish Auckland's tourist beaches
Sand is a non-renewable source
Deposited during the Holocene
Few siezeable rivers
Thought that the sand was deposited from offshore
Coastal sed. budget is a closed sys. - outputs from mining are not replaced by inputs from rivers + offshore
Extraction rates exceed inputs *5
Impact on Landforms
Closed nature of sed. cell = current extraction rates are unsustainable
Beaches
Starved of sed. = wider + flatter
Less effective at absorbing waves
Higher energy waves erode the beaches = dunes + spits are vulnerable
Foredune ridges
Undercut by wave action
= Steep, sea-ward facing scarps
Loss of veg. cover = susceptible to aeolian processes
1978 storms
Breached Mangwhai spit
Altered tidal currents = sedimentation of Mangwhai's harbour
Shallower water in harbour = flood threat for community
Dredging harbour + groynes helped restore some equilib.
Retreat
Already evident
LT retreat by end of century = 35 m
Estimates are higher than any of the Auckland region's other 123 beaches