Question | Answer |
What is topography, relief and geology? | Topography = shape of the coast. Relief = height and slope of the land. Geology = rock type. |
What is a concordant coastline? | Strata of rock run parallel to the shoreline so the waves approach one type of rock, fewer bays and headlands |
What feature occurs in concordant coastlines? | Coves e.g. Lulworth Cove. Waves attack faults in the hard rock on the shore and easily erode the soft rock inland, forming a circular bay |
What is a discordant coastline? | Strata of hard rock (chalk, granite) and soft rock (clay) run perpendicular to the shoreline |
What is a headland? | Discordant coastline - soft rock is easily eroded forming bays, and this leaves hard sections of rock jutting out into the sea |
What is an arch, stack and stump? | Discordant coast- waves attack faults in headland, cracks -> caves, 2 caves erode into the back of each other forming an arch. Roof is weathered (frost, wind, rain) & arch base is eroded by wave action, roof collapses -> stack. Erosion: stack->stump |
What is a wave-cut platform? | The cliff face is weathered by frost, wind and rain, and the cliff base is eroded by wave action, forming a wave-cut notch which increases in size, the cliff collapses and retrests |
What is longshore drift? | The zigzag transportation of material along a coast. The swash of waves carries the load up the beach at an angle dependent on the direction of the prevailing wind, the backwash flows back out to sea at 90 degrees due to gravity. |
What is a spit + tombolo + bar? | Spit is stretch of sediment, projects out to sea, attached to mainland at one side. Tombolo is a spit connecting island to mainland. Bar is a spit across a bay, joining 2 headlands, sheltered lagoon forms behind (mud flats/ salt marsh). Longshore drift! |
How does a fjord form? | A glacier forms a U-shaped valley, glacier retreats,water fills resulting valley floor forming a narrow, steep-sided inlet attached to the sea |
What conditions do mangrove swamps require? | Tropical coasts, flooded twice daily by tides, soft soils. |
What is cliff -foot erosion? | Where water breaks up and removes rock from the cliff base. Hydraulic action, abrasion, corrosion. |
What is hydraulic action? | Waves trap air inside cracks in the cliff, air is compressed when waves retreat which weakens the cracks, rock fragments fall away. |
What is abrasion? | Load carried by waves grinds down the cliff base |
What is corrosion? | Weak acid in sea water dissolves alkali rock e.g. limestone |
What are sub-aerial processes? | Processes that affect the cliff face. Weathering and slumping |
What are the types of weathering / what is weathering? | Weathering is where the atmosphere and plants break up rock. Physical - freeze-thaw mechanical weathering. Biological - seedling roots enter cracks in rock, root growth enlarges cracks and breaks rock. Chemical - CO2 and SO2 acid rain |
What is mass movement? | Slumping is where wetting & drying of clay causes it to expand & shrink, cracks develop in the dry season, rainwater percolates the cliff, clay becomes lubricated and heavy, gravity causes clay to slide down dope and slumped material is washed away by sea |
What factors affect the rate of erosion? | Geology & resistance of rock. Wave energy (fetch) which depends on distance travelled by waves, whether the sea is enclosed and sea currents. Load carried by waves. Low-pressure weather systems produce strong winds and waves. Human factors e.g. dredging |
What is coastalisation + examples? | THe movement of people towards coastal areas e.g. towards Spanish Costas, Queensland Coast, Miami coast, Bournemouth and Poole |
What has caused coastalisation to the Spanish Costas? | Physical: warm Med sea, sandy beaches, long summer season, interesting architecture, national parks. Lax plannign regulations -> rapid growth of tourism infrastructure. 1980s growth of salaries, cheap flights, package holidays - affordable destination |
What has caused coastalisation to the Queensland coast? | physical: World Heritage sites (Daintree tropical forest, Great Barrier reef, mangrove swamps), warm climate all year round, sandy beaches. Investors attracted by low taxes, open space for development. Low property prices |
What has caused coastalisation to the Florida coast? | Physical: Everglades, near Caribbean island, warm climate, sandy beaches. Miami - port attracts economic migrants and tourists, centre of finance, commerce and entertainment, Walt Disney World resort. Retirement migration flows |
How is the history of Bournemouth and Poole similar to the idealised coastal model? | Victorian period - railway linked Bournemouth + London, visitors attracted by warm weather, new coastal hotels, high environmental quality, pier. 1960s decline - cheap package holidays in Europe and cheap flights, de-multiplier effect, hotels run down |
How does Bournemouth differ to the idealised coastal model? | Regeneration in 1980s. Increase in 3ary sector (JPMC bank 4,000 employees) due to skilled grads from university, open space for development, easy commuting to london and airport links to europe. Council encourages regeneration of brownfield sites... |
Continued | Retirement migration flows from South-East England due to cheaper property prices and elderly facilities. Maintains young population due to nightlife, university and student accomodation |
Why is Southampton a good location for trade? | Located on Solent so can be reached by tankers. Good accessibility to the rest of the UK. UK's 2nd largest container port. Open space for developement |
What are the pressures on the Southampton coastline? | Coastal squeeze between New Forest National Park + Solent. Expansion of suburbs creates problems about sewage disposal. Industrial development takes up space + industrial discharge (effluent + metal) damages ria ecosystem. Leisure usage |
Continued | Proposal for container port at Dibden bay - 3000 jobs, cruises, trade. Conflict: NIMBYs and English Nature/ Friends of the earth - SSSI, dredging, urbanisation, pollution, oil spills. Fawley oil refinery - oil spills, reduces size of salt marsh, trade |
Why is there rapid erosion of the Holderness Coast? | Weak boulder clay, rip currents, low pressure systems create storms |
What are the options for shoreline management? | Do nothing-no coastal defence activity, let existing defences collapse. Retreat the line- allow coast to erode back to a certain point. Hold the line-hard engineering keeps coast in place. Advance the line - move coastal defences forwards into sea |
What is hard engineering? | Building structures along a coast (base of cliff or on a beach) to try to reduce erosion |
What are examples of hard engineering? | Groynes trap sediment prevent longshore drift friction absorbs wave energy. Revetments are large ramps on a beach air spaces absorb wave energy, made of timber/concrete/rocks. Gabions are rocks in cages, stakced to make walls, absorb energy |
Cont | Sea walls are curved concrete walls that reflect wave energy. Cliff drainage - removal of water from rocks reduces chance of landslides and slumping. Cliff fixing - insert steel rods into cliff face to absorb wave energy and stabilise cliff |
Where are some examples of hard engineering along the Holderness coast? | Groynes - Hornsea to keep a beach for tourism, Spurn Head as it is important for shipping. Revetments - Easington to protect gas terminal |
What are advantages and disadvantages of hard engineering? | ADV: reassures public, used for hold the line management. DISADV: expensive to build & maintain, defences in 1 location may increase erosion & flooding elswhere, destroy natural beauty of coastline, can't keep pace with rising sea levels |
What is soft engineering? | Uses natural processes in the coastal system to try to manage erosion |
What are examples of soft engineering? | Sand is pumped from seabed to replace eroded beach, friction absorbs energy. Reshape beach to reduce erosion. Develop natural coastline e.g. mangrove, coral reefs. Offshore reefs - old tyres/waste fastened together & sunk. Kilnsea ditches->humber |
What are costs/benefits of soft engineering? | ADV: cheaper, more sustainable, lower environmental impact, retains natural beauty of coastline, can adjust to wave energy. DISADV:can involve the loss of property or land |
What is ICZM / SMP? | Involves hard and soft engineering, takes into account the processes of an entire coastal sub-cell so the coastal sections are managed as a whole, encourages communication between locals and authorities, sustainable |
What are the criteria for coastal management strategies? | Feasibility from an engineering viewpoint. Cost-effectiveness, through a cost-benefit analysis. Appropriateness - risk assessment, environmental impact assessment |
Why is Bangladesh vulnerable to sea level rise? | High population density, melting Himalayas ice is causing river flooding, sea level rise (1m between 2010-50) causes erosion and flooding, low-lying coast 60% below 1m, delta made of mud/silt, MHZ, rivers cause inland flooding, climate change |
What are the 2 management strategies? | Dhaka Integrated Flood protection project and Oxfam's River Basin Project |
What is the Dhaka integration flood protection project? | Phase1: hard -levees, floodwalls after 1988 floods. 1998 floods breached incomplete floodwalls, pumping stations inadequate. Phase2: soft - flood forecasting, floodplain zoning, land-use planning regulations, better emergency response, communication |
What is Oxfam's River Basin Programme? | Aims to improve preparedness for flooding and reduce homelessness, deaths and loss of possessions. Building homesteads 5m above sea level, flood shelters that accommodate 300 households, rescue boats to collect people, possessions, livestock |