Block 9 (Coastal Processes Are A Vital Context For Human Activity) Flashcards
Of all inhabited continents, which is the only one where more people live in the interior zone than the coastal zone?
Africa
By 2025 what percentage of the US population is estimated to live in the coastal zone?
75% (despite it only being 17% of the landmass)
What are the positive impacts of the coast on humans?
- Tourism + recreation (Natural beauty + available activities)
- Settlement (Natural beauty + employment opportunities)
- Fishing
- Agriculture (Tidal mudflats can be drained to provide fertile farmland)
- Trade/port development (Rias provide deep water ports - e.g. Milford Haven, Pembrokeshire, shallowest at 17m)
- Transportation (Ships - can get far inland in rias - 16km inland at Southampton) (Roads + rails - flat marine terraces - River Clyde Estuary, Scot, A8 + M8 + railways)
- Energy (Oil + gas + renewables - tidal + wind)
How has tourism changed over the past 200 yrs
Tourism has grown into a major economic activity
19th C - Rail - Facilitated growth of British seaside resorts
Recently - Air - Facilitated growth of foreign seaside resorts for wealthy
What are natural features that attract humans to the coast + named examples?
- Scenery (e.g. CASS sequences, Dorset coast)
- Ecosystems (e.g. coral reefs, Great Barrier Reef)
- Sunny, hot climates with sandy beaches (e.g. Spanish coast)
- Safe seas without strong currents (e.g. Maldives)
- Large waves for surfing (e.g. Gold Coast, Australia)
What are human features that attract people to the coast + named examples?
- Heritage sites (e.g. White Cliffs of Dover)
- Cultural sites (e.g. West Bay, Dorset - where Broadchurch was filmed, 10 mill views per ep, 77% increase in local customers, 50% businesses attributed this to the show)
- Activities/service provision (e.g. Dubai)
- Watersports
What positive effects does tourism bring to the coastal zone?
- Helps local + national economy (2016, England seaside tourism contributed £8 bill)
- Helps employment rates (largest legal employer - range of skill sets)
- Positive multiplier effect in local area, as more locals are employed
- Services + infrastructure are improved to cater for tourists, and become available to locals (Benidorm increased capacity from 69,000 in 1960s to 4 mill today)
- FDI from TNCs attracted as area becomes more developed + attractive, which boosts employment + development further
What are the negatives of tourism?
- Positive multiplier effect can be limited, by leakage abroad in TNCs + all-inclusive tourism deals
- Services may be closed out of season, so benefit locals
- Employment often seasonal + low pay, as locals rarely given skilled jobs
- Traffic congestion
- Increased second-home ownership, which ruins community by outpricing locals (e.g. Salcombe is 43% second homes/holiday lets)
- Environmental decline - footpath erosion (e.g. Lulworth Cove - Durdle Door path has eroded down 30cm), pollution (air + litter), damage to ecosystems (Cancún, Mexico 57ha mangrove cleared for tourist complex in 2016)
What are the negative impacts of the coast on humans?
Coastal erosion
- Exacerbated by inappropriate coastal development + management
(Areas surrounding these areas often have worst erosion rates due to promontory effect)
When is erosion naturally worst?
During a storm event
What is the average erosion rate in England + how has this been calculated?
Average 1.5m/yr eroded
- Calculated we have lost 2 miles since Roman times 2000 yrs ago (including 35 villages)
Why is erosion increasing?
Eustatic sea level rise
- More areas of coasts are vulnerable
- Waves have higher erosional energy (warmer)
What are the negative social + economic effects of erosion?
- Danger to life (e.g. mass movement)
- Damage to homes + buildings (BGS est 113,000 residential + 9,000 commercial at risk)
- Damage to lifeline infrastructure
- Loss of valuable agricultural land (BGS est 5,000 ha at risk)
- Falling property prices
- Psychological stress for residents
- Loss of tourism + leisure facilities due to destruction of beach
What are the negative environmental effects of erosion?
- Low lying coastal areas at risk of flooding
- Loss of vulnerable ecosystems
What is the promontory effect?
Some areas protected - protrude, acting as groynes/headlands
- Starve downdrift from sediment, by blocking LSD
- Accelerate erosion either side, by causing wave refraction
What are the 5 coastal management strategies?
- Do nothing
- Managed retreat/realignment
- Hold the line
- Advance the line
- Limited intervention
What is the do nothing management strategy?
Allow natural processes (erosion) to continue
What is the managed retreat/realignment strategy?
Allow shoreline to move inland, in a controlled way, to a new line of defence
What is the hold the line management strategy?
Use hard + soft engineering to protect present shoreline position
What is the advance the line management strategy?
Use hard engineering + dune growth to move shoreline seaward
What is the limited intervention management strategy?
Accommodate the issue of erosion (e.g. building on raised platforms)
What are the hard engineering strategies?
- Sea walls
- Recurved sea walls
- Rock armour
- Gabions
- Groynes
- Revetments
- Drainage
- Offshore bars
- Rock bund
What is a sea wall?
HE
Concrete structure at cliff foot to absorb wave energy
What is a recurved sea wall?
HE
Sea wall with a curve, to encourage wave reflection (CLAPOTIS EFFECT)
What is rock armour?
HE
Large rocks to absorb wave energy
What is a gabion?
HE
Cage filled with small rocks to dissipate wave energy
What is a groyne?
HE
Wooden/stone structure perpendicular to shoreline to reduce LSD
What is a revetment?
HE
Wooden/sloping structure parallel to shoreline to absorb some wave energy, whilst allowing some sediment flow
What is drainage?
HE
Removing water in cliffs to remove lubricated slip plane + reduce landslides
What is an offshore bar?
HE
Rocks placed offshore to absorb wave energy before they reach beach
What is rock bund?
HE
Row of rocks along beach to absorb wave energy
What are the soft engineering methods?
- Beach nourishment
- Beach reprofiling
- Beach recycling
- Coastal fencing/hedging
- Replanting vegetation
- Cliff profiling
What is the beach nourishment management strategy?
SE
Sand/shingle added to beach
What is the beach reprofiling management strategy?
SE
Shape of beach changed to absorb more energy
What is the beach recycling management strategy?
SE
Sediment moved along beach to counter LSD
What is the coastal fencing/hedging management strategy?
SE
Fencing/hedging to reduce sand blowing away + destroying dunes
What is the cliff profiling management strategy?
SE
Reducing cliff angle to improve stability + reduce mass movements
What is the definition for hard engineering?
Building artificial structures, which try to control natural processes (erosion)
- More expensive
- Shorter term
- Greater environmental impacts
What is the definition for soft engineering
Working with nature to try to reduce the extent of natural processes (erosion)
- Less expensive
- Longer term
- More environmentally sustainable
What must be drawn up for every sub-cell of coastal areas?
Shoreline Management Plan (SMP)
What physical factors affect the type of management implemented in an area?
- Geomorphology (resistance of rock)
- Dynamism (how rock will react to intervention)
- Quality of environment (if its worthwhile protecting)
What human factors affect the type of management implemented in an area?
- Local + national budgets
- Demographic + their opinion
- Scientific research considerations
What process is used to determine the extent of management that should be implemented in an area?
Cost-benefit analysis
Costs must be outweighed by benefits to employ strategy
What are the benefits of coastal management?
- Increased security for clifftop population
- Increased security for beach users
- Reduced compensation costs
- Soft engineering methods can be attractive + helpful (e.g. increase biodiversity)
What are the negatives of coastal management?
- Expensive (e.g. sea walls = £5000/m, £12,000/m if recurved)
- Reduced exposure for scientific study
- Disruption of natural processes (the equilibrium)
- Disruption of natural habitats
- Hard engineering methods can be ugly
