Flashcards
coastal management
Flashcards do conjunto (38)
- 1what are the 2 main aims of coastal protection/management?- provide defence against+mitigate effects of flooding
- provide protection against+mitigate impacts of coastal erosion - 2what are the other aims?- stabilising beaches affected by longshore drift
- stabilising sand dune areas
- protecting salt marshes - 3why is there a need for coastal intervention/protection?- climate change + global warming
- eustatic + isostatic sea level rise
- storm events > flooding
- fragile/dynamic environments
- coastal processes: waves, currents, tides, transportation, etc - 4which areas are most at risk?- fragile/dynamic landforms
- high energy environments
- areas adjacent to large fetch
- geology of cliffs like boulder clay, e.g. East Yorkshire
- economic high level value like cities @ risk from flooding
- areas @ sea level, e.g. maldives - 5what are the 4 coastal management options?- do nothing: when value of built env does not exceed cost of installing coastal defences - not env, tech or economically viable
- hold the line: retain existing coastline, maintain current defences/build new ones where existing structures no longer provide protection
- managed retreat/realignment: actively manage the rate+process by which coast retreats
- advance the line: build new defences seaward of coastline - 6what is soft engineering?- using natural systems for coastal defence, e.g. beaches+dunes, which can absorb+adjust to wave+tide energy
- involves manipulating+maintaining these systems without changing fundamental structures - 7what are example of hold the line strategies?- beach nourishments
- dune regeneration - 8what are examples of managed retreat/realignment?- managed retreat
- land-use management - 9how does beach nourishment work?= attempt to replace material lost through longshore drift
- councils often move material from one end of beach to another before start of tourist season
- nourished beach means: fewer waves reach back, wave energy absorbed+dissipated by beach so rate of erosion reduced - 10how does land use management work?- even if erosion/flooding inevitable, local authority may be able to mitigate impact
- addressing peoples behaviour+educating local community
- encourage land owners to think about how they can use land @ risk
- cannot remedy damage already done - 11how does sand dune regeneration work?- most damage=removal of vegetation by agriculture/tourism > blowouts, sand moved inland
management strategies:
- replanting vulnerable areas (marram grass) + stabilising surface with sacking/wire mesh
- afforestation with quick growing conifers
- selective grazing
= artificial creation of new sand dunes/restoration of existing ones
sand dunes = physical barrier between sea+land - 12how does managed retreat work?= when decision made to no longer follow 'hold the line'
- people moved out, buildings demolished, etc so sea can inundate land > salt marshes to reduce wave power + act as defence against rising sea level
- sustainable long-term solution
e.g. areas like California already requirements on stretches of coastline that building must be certain distance from shoreline - 13why might 'do nothing' be a viable solution?- since start of 21st century people begun questioning whether we should protect the coast
- tens of millions of £ spent annually in UK
- might be cheaper to let nature take its course+pay compensation to those affected
e.g. storms of Dec 2013+Jan 2014 hard sea defences in Devon+Wales proved ineffective - 14what is hard engineering?- involves making physical change to coastal landscape
- uses restraint materials, e.g. concrete, boulders, wood+metal
- often large scale+huge cost
- each built with specific purpose
- advance the line - 15what is the main benefit of hard engineering?they are long lasting+effective over planned lifespan
- 16what are the disadvantages of hard engineering?- structures can be expensive to build+maintain, e.g. to repair sea wall can cost >£5000/m
- defence in one place can have serious consequences for another area of the coast
- structures are sometimes eyesore, spoiling landscape+physically disrupting natural habitats - 17how do sea walls work?- aim to dissipate wave energy
- recurved structure throws waves back out to sea into path of oncoming > reducing its impact
- provide physical barrier to flooding by raising height of coastline
- must have continuous facing as any slight gap will be exploited by HA, also need drain outlets so water doesnt accumulate inland - 18how does rock armour work?- consists of large boulders dumped in front of a cliff/sea wall to take full force of waves
- boulders = angular so larger surface area+gaps
- usually not fixed in place so rock/move slightly (taking energy) - 19how do gabions work?- operate on same principles as rip-raps
- but smaller boulders contains within steel wire-mesh cages, often joined together to form larger structures/walls - 20how do revetments work?= concrete/wooden structures placed across a beach/coastlines
- take full force of wave energy > preventing further erosion of coast - 21how do groynes work?= wooden/steel/stone breakwaters built nearly @ right angles to waves
- built to control longshore drift by trapping sediment to create higher+wider beaches which will dissipate wave energy
- groynes themselves also break up waves
- may have serious effects down coast where will cut off supply of sediment+could leave coast exposed to erosion - 22how does cliff fixing work?- often done by driving iron bars into cliff face
- stabilises it + absorbs some wave power - 23how do offshore reefs work?- force waves to break offshore
- reduces their impact on base of cliffs - 24how do barrages work?= large structures built to prevent flooding on major estuaries+other large sea inlets
- acts as dam across estuary+prevents incursion of seawater
e.g. that part of Delta Plan in Netherlands - 25are there sustainable approaches to coastal management?- since 1990s have focused on sustainability
- shoreline management plans (SMPs): policies used by UK gov to make coastal management more sustainable
- integrated coastal zone management: policies developed @ global scale which seek to create common+integrated approach around world - 26what is an example of how coastal management can be unsustainable?- Northumberland only 1 out of 5 counties in sediment cell 1
- if they build groynes they would starve beaches of sediment in N Yorkshire > decline in tourism industry
= unsustainable as gov would have to pay for further management in NY to ensure county's income - 27what year did the government introduce SMPs?1995
- 28how many SMPs are there around coast of England+Wales22
- 29what is the aim of SMPs?to identify the most sustainable approach to managing flood+coastal erosion risks to coastline
- 30what do they plan for?- short term (0-20 yrs)
- medium term (20-50 yrs)
- long term (50-100 yrs) - 31what are the main features of SMPs?- provide assessment of risk with evolution of coast
- address risk sustainably
- provide policy for coastal defence management planning
- promote long-term management policies for 22nd century
- be technically sustainable, env acceptable + economically viable - 32when was ICZM devised?UN earth summit 1992
- 33who developed it to promote integrated coastal management?the European Commission
- 34they realise that coastal zones are ...- some of the most ecologically productive areas of world
- popular for settlements, tourism, business+ports
- home to 200 mill people in Europe - 35BUT this economic activity+concentration of people is causing ...- biodiversity loss
- habitat destruction
- pollution
- conflicts between stakeholders
- overcrowding - 36which are all made worse by the fact that ...- coasts = some of most vulnerable areas to climate change+natural hazards
- coasts = especially @ risk of flooding, erosion, sea level rise+extreme weather events
- lives of people in many coastal communities are already changing due to impacts - 37it is an 'ecosystem approach' with strategies like ...- natural conservation/protection
- aquaculture (farming marine organisms, e.g. lobster farm)
- fishing
- agriculture
- offshore wind energy
developments to adapt to+mitigate climate change - 38if conducted properly, it should act in a cycle (generating feedback) of:1) planning
2) decision making
3) managing+monitoring of implementation
4) information collection
(then back to planning)
Informações
- Descrição
- GCSE Geography (coasts) FlashCards sobre coastal management, criado por serena norman thomas em 25-04-2018.
- Criado por
- serena norman thomas
- Visualizações
- 1
- Avaliação