Coasts EQ1 Flashcards
Importance Of Vegetation on Sand Dunes
- stops erosion
- land accretation (growth)
- creates new habitats
Formation of a Dalmation
fluctuations in sea level result in dalmations
low sea level = erosion of geology
high sea level = submerging of geology and only the top part is exposed
Formation of a Haff
sediment such as sand and gravel is transported in rivers, currents and through longshore drift.
when wave energy and current is low and sediment load is high it results in deposition
overtime sediment accumilates and forms and barrier which seperates the open sea from the coastal lagoon.
Factors effecting coastal morphology (shape)
- wave action - constructive and destructive waves = concordant and discordant coasts
- geology - hard and soft rock = faults, joints and other lines of weakness
- sea level change = dalmations
Morphology meaning
shape of coast
lithology meaning
geology characteristics
eg. hard/soft rock
eg. ignoeus, metamorphic and sedimentry rock
eg. faults, joints and other lines of weakness
How does geology effect the coastal landscape
- type of rock - hard and soft rock = concordant and discordant coasts
- bedrock lithology- Igneous, metamorphic and sedimetary = rates of erosion
Formation of a wave cut notch and platform
- destructive waves with high energy attack the bottom of the cliff causing erosion by hydraulic action ( ) and abrasion ( ).
- overtime this leads to an undercut of the base of the cliff = wave cut notch
- eventually as more undercutting takes place, cliffs over arching rock becomes unstable and collapses
- when the over arching rock collapses, it eventually moved inland in a sloped shape= wave cut platform
- wave cut platform is exposed at low tide
Formation of a Crack-Stump
- It forms around a headland and forms by air being trapped in fault lines and joints of a rock and destructive waves hit against the rock causing pressure and leads to the rock chipping off creating a crack - erosion by hydraulic action.
- Erosional processes widen the crack overtime leading to dislodged rock and erosion causes this to become a cave
- more erosion takes place and overtime the waves break the rock through the headland and forms an arch
- the rock above cannot hold itself and becomes unstable and evetually collapses leaving a stack
- the stack is undercut by erosion and collapses too leaving behind a stump which is visible at low tides
eg. durdle door, dorset
Importance of vegetation - Protecting the coast
Salt marshes and mangroves work to protect the coast from erosion. The extensive roots bind soil together and reducing impacts of winds, waves and currents. salt marshes and mangroves provide a natural barrier for flooding and storm surges as the dense roots dissipate wave energy reducing impacts of flooding. The natural barrier helps stop impacts of erosion, protecting local communities and integrity of thr natural landforms.
Importance of Vegetation- land accretation (growth)
coastal vegtation can help trap sediment from waves and currents this sediment accumilates around the plants and contributes to land accretation, encouraging the growth of new land. saltmarshes and mangroves help bind sediment together with their roots amd this builds up new land, stabalising the dune, providing more strong and effective protection for the coast against erosion
Importance of vegetation- habitat creation
the build up of sediment can help create more land and growth of the sand dune which can help unique species such as planys adapted to harsh conditions, coastal birds and burrowing animals . these habitats can help contribute to local biodiversity and increase ecological resilience.
ICZM- Sustainable coastak management
Aims to holistically manage the coast keeling in mind local communitues, jobs and sustanablity. it works together with stakeholders and natural processes to manage the coast through adaptive management.
Case study = Blackwater eastury
Sustainble coastal management
Managing flood risk- soft engineering
ICZM - holistic management
Adaptation- evacuation and building stratagies
Managing natural resources
Case studies for coastal managment
Holderness, Hornsea
Happisbrugh, Northfolk
Southsea, Portsmouth
Lincolnshire Beach
Blackwater Eastury
Maldieves
Tuvalu
Does hard engineering create more loosers
Intro-
Yes- it benifits who can afford it - after hurricane katrina, ses walls were build for wealthy parts of new orleans and poor parts were left vunerable.
Yes- tourism industries get effected - swanage - stragaties like steps to make beach accessible have been implamented
No- doesnt create winners or loosers but its bad, its costly and bad for the environment. disrupts the sediment cells eg. hornsea coast
No- benificial and effective eg. southsea coastal scheme aims to savs 10,000 houses and 700 businesses during sea walls and rock armour.
concl
Does sustainable management protect the coast ?
Intro-
Yes- Soft engineering stratagies aim to reduce impacts of erosion eg. lincolnshire coast
Yes-
No- sustainable management focuses more on economic and enviromnetal factors which need to be protected therefore forget how hard engineering is very effective
No- doesnt take into account uncertainity of sea level change and that sustinable management wont be effective for sea level rise and rise in erosion
Mega disaster case study Boxing day Tsunami 2004
14 countries surrounding the indian ocean was effected
220,000 deaths
major economic losses in sri lanks, thailand, somalia
Case Study- Japan 2011
Decstructive Margin- subduction of eurasian and pacific plate
16,000 people died
city of sendai was completly destroyed
Case Study - E15 eruption Iceland
Conservative Plate - strong magma plume rose
100,000 flights cancelled due to ash cloud in the air
causing economic loss of $1billion
over 20 european countries were effected
Case Study- Sichuan 2008
69,000 deaths
$140 billion loss
Case Study- Mount Pinatubo 1991
Destructive margin
850 deaths
650,000 jobs lost
Case Study - Haiti 2010
conservative plate
mag 7
360,000 deaths
30% increase in poverty
Social Impacts of tectonic hazards
Loss of life and homelessness eg. Haiti= 360,000 deaths and over 1milliom people homeless
significance depends on magnitude of event
