Coastal Landscape

HideShow resource information
Littoral Zone
The wider coastal zone, which included adjacent land areas, the shore and the shallow part of the sea just offshore it comprises four sub-zones: coast, backshore, foreshore and nearshore.
1 of 68
Classifying Coasts
Can be classifed in a various of ways: Geoglogical Charateristics, impact of sea-level chnages, the dominant coatsl process.
2 of 68
Classifying Coasts
Rocky or cliffed, land and sea distinction clear, height of cliffs give exposure to erosive forces of the sea, rain, wind creating high engery coastline.
3 of 68
Classifying Coasts
Coastal plains- Where the land slopes gently towards the seaand there is almost imperceptible state of dynamic equilibrium between the desposition of sediment by river stems. These are typically low energy coastlines.
4 of 68
Roacky Coasts and Coastal Plains
Rocky coasts result from a geology that is resistant to the erosvie forces of the sea and the weather in high energy enviormnets. Coastal plains are found in areas of low relif and depend on the supply of terrestrial sediment.
5 of 68
Geological structure
The arrangement of the rocks in three deimensions and involes three key elements: Strata, the different layers of rock in a location and how they relate to each other.
6 of 68
Geological Structure
Deformation, the degree to which rock strata have been tilted or folded by tectonic activity. Faulting, the presense of fractures along which rock have moved.
7 of 68
Concordant
Formed when rock strata runs parallel to the coastline. the typical coastaline is generally smooth or slightly indented one, also known as Dalmation type.
8 of 68
Discordant
Formed when Differnet rock strata inteesects the caost at an angle, so that lithology varies along the coastline. They typical coastline is one of basy and headlands.
9 of 68
Cliff Profiles
Influences by two differnet aspects of geology: the resitants of the rock to erosion and the dip or angle of the rock strata in relation to the coastline.
10 of 68
Rates of Erosion- Igneous
Granite, Basalt, Dolerite- Very slow, rocks are resistnat to erosions beacuse the crystalline and usually have few joints
11 of 68
Rates of Erosion- Metamorphic
Slow- Crystalline rock are resistant to erosion, theses rocks are often folded and fractured and therefore vunerable to erosion.
12 of 68
Rates of erosion- Sedimentary
Moderate to fast- they often erode faster that the other two types, younger rock tends to be weaker and rocks with bedding planes and fractires are more vunerable to erosion.
13 of 68
Coastal Vegetation
Many of the plants that grow there are are Halophytes and xerophytes which mean that they can grown in sandy and salty areas.
14 of 68
Coastal Vegetation
Once they are capable of livin gin these conditions thye trap more sand and lead to the formation of embryo dunes they gradually become fixed and plant cover develops the climax of the community of woodland.
15 of 68
Halophytes
Plants that can tolerate salt water, be it around their roots, being submerged at high tide or being sprayed by the sea
16 of 68
Xerophytes
Plants that can tolerate very dry conditions as these found in coastal sand dunes
17 of 68
Plant Succession
The sequential development of vegetation froms its inital establishment on bare ground through to the ultimate vegetation cover or climax plant community
18 of 68
Waves
Caused by friction between the wind and water. they influence the three marine processes of eroison, transport and deposition. Wvae size depends on - Strength of the wind, the length of time the wind blows for, water depth and wave fetch
19 of 68
Fetch
The uninterrputed distnace across water over which the wind blows. it is the distnace over which waves are abel to grow in size.
20 of 68
Constructive Wave
are of low height and long length. Thye have a strong swash and weak backwash.
21 of 68
Destructive Wave
relativly high with short length. they have a storng backwash whihc helps to erode and carry away beach material.
22 of 68
Beach Morphology
Waves over time bring chnages to beach morphology. there are 4 diagnostic features. Storm beach , the result of C waves in stromy conditions. Berms- small ridges by C waves in calm conditions.
23 of 68
Beach Morphology
Cusps- gentle D waves eroding berms. Offshore bars: formed by persistant D waves.
24 of 68
Beach Morpholgy Definition
The shape of the beacj includinf it width and slope and features such as berms, ridges and runnels. it also included the type of sediemtn forming the beach.
25 of 68
Erosion Processes
Waves apporach the caost at a right angle, the tide is high, heavy rainfall has weakend the cliff, debris at the foot of the cliff has been removed and no longer protects the critical point.
26 of 68
Marine Erosion
Hydraulic Action- wave quarrying when air is trapped in the joints and cracks is compresses by the force of waves crashing agaist the cliffs
27 of 68
Marine Erosion
Abrasion- sediment being carried in the waves has a wearing down effect
28 of 68
Marine Erosion
Attrition- the wearing down of sediment as it is moved around by the waves
29 of 68
Marine Erosion
Corrosion- Carbonate rocks such as limestone are dissoved by rainwater sea spary and seawater
30 of 68
Sediment Transportation
Traction- heavier sediment rolls along the sea floor pushed by wvaes and currents
31 of 68
Sediment Transportation
Saltation - Sediments bounces along the floor
32 of 68
Sediment Transportation
Suspension- fine sediment is carried within the body of the water
33 of 68
Sediment Transportation
Solution- dissolved sediment is carried in the water as a solution
34 of 68
Depositional Features
Bayhead beach- an accmulation of sand at the head of a sheltered streach of water between two headlands
35 of 68
Depositional Features
Spits- a sand or shingle beach ridge extending beyond a turn in the coastline
36 of 68
Depositional Features
Recurved hoocked spit- a spit built out into a bay or across an estuary the end of which curves landwards into shallower water
37 of 68
Depositional Features
Bar- a sand or shingle beacj extending across a coatsl indentation with a lagoon behind
38 of 68
Depositional Features
Tombolo- a sand or shingle bar that attaches a former offshore island to the coast
39 of 68
Depositional Features
Cuspate foreland- a triangular area of shingle extending out from a shoreline, possibly foremd by longshore drift form opposing directions
40 of 68
Sediment Cells
Long streches of caostline that operate as almost self contained physical systems. in each sediment cell there are sources where sediment is generated. e.g eroding cliffs and beaches, transfer zones, ect.
41 of 68
Weathering
mechanical, the breackdown of rocks by some form of phyical force, chemical - involving a chemical reaction and decomposition and biological the action beacteria, plants and animals which speed up the other weathering processes.
42 of 68
Mass Movement
Rockfalls occur where the rock on a cliff is being undercut by the sea is weakend by weathering. falls can be sudden and spectacular
43 of 68
Mass Movement
Rotational Landslides are slow downslope movements of a mass of rock or debris over a curved plane. they are particularly common where permeable rock overlies an unstable impermable rock.
44 of 68
Mass Movement
Landslides are sudden downslope surges occuring when weathered rock and soil become staturated and lubricted by water.
45 of 68
Sea Level Change
Changes can be very short change however over a long time sea-level changes are permenant and they have complex factors. it can be down to land and sea change land level isotatic change and sea eustatic change
46 of 68
Submergent Coast
A marine transgression can result form a eustatic rise or an isotatic change in both cases large areas of the land are submerged beneath the sea prodcuing a submergent coast.
47 of 68
Contemporary Sea-Level Change
Impact of global warming- rising about 2mm a year. Thermal expansion of the oceans as they are warmed. The ice sheets melting adding to the volume of water.
48 of 68
Rapid Recession - Physical Factors
Long wave fetch and large D waves, Strong longshore drift, soft or unconsolidated geology and cliffs with structual weakeness.
49 of 68
Rapid Recession- Human Activity
Dreding the offshore seabed for sand and gravel, river dams reducing the supply of sediment to the coast, coastal managment.
50 of 68
Coastal Flooding- Factors
High-risk areasd include costal plains, estuaries and deltas the risk being increased by rsing sea level and human actions such as coatal veg removal, building coatsl resort.
51 of 68
Storm surges
short time rise in sea level caused by low air pressure, low lying coatal areas are capable of causing immense damage and destruction.
52 of 68
Climate Change
Storm surges , cyclones and depression have always been a part of weather but the concern is the frequency of such events that ehnace global warming.
53 of 68
Coastal Managment -Economic
These include the loss of property in the form of homes and businesses, the loss of transport and farmland.
54 of 68
Coatal Management- Social
impact on people , such as cost of relocation and community disruption as well as impacts on health and well being.
55 of 68
Costal Management- Enviormental
loss of coatsl habitats and ecosystems
56 of 68
Enviormental Refugees
People and communites forced to abandon thier homes due to natural processes may be sudden as with landslides and volcanic eruptions or gradual suach as coatsl erosion and rising sea levels
57 of 68
Hard Engineering
Sea defences - Sea wall, Rip rap, rock breakwaters, revetments, groynes.
58 of 68
Hard Engineering - advantages
It is obvious to those at risk that something is being doen to protect them, It can be a one-off action that proctets for decades
59 of 68
Hard Engineering- Disadvantages
High Costs, Can seek faults, not visually attractive, costal systems can be effceted, adverse affects along the coastline
60 of 68
Soft Engineering
Beach Nourishment, Cliff stabilisation, dune stabilisation
61 of 68
ICZM- Rio summit 1992
That the entire coastal zone needs to be managed, not just the zone where the breaking waves are causing erosion or flooding
62 of 68
ICZM- Rio summit 1992
the importance of the coastal zone to peoples livelihoods and well-being
63 of 68
ICZM- Rio summit 1992
the need to make management of the coast substainable
64 of 68
Is it a joined up or holistic appraoch
Plan for long term, involve stakeholders and they have the right, follow an adaptive approach, try to work with natural processes
65 of 68
The hard part is decision making
no active intervention, hold the line, managed realignment, advance the line.
66 of 68
Management options
the economic value , the technical feasibility, enviromental sensitivity, pressure from local communities
67 of 68
ICZM
It is key that they rarely please everyone. there are embeded conflicts of intreset. the government an council are limited to funds so not all can be protected.
68 of 68

Other cards in this set

Card 2

Front

Can be classifed in a various of ways: Geoglogical Charateristics, impact of sea-level chnages, the dominant coatsl process.

Back

Classifying Coasts

Card 3

Front

Rocky or cliffed, land and sea distinction clear, height of cliffs give exposure to erosive forces of the sea, rain, wind creating high engery coastline.

Back

Preview of the back of card 3

Card 4

Front

Coastal plains- Where the land slopes gently towards the seaand there is almost imperceptible state of dynamic equilibrium between the desposition of sediment by river stems. These are typically low energy coastlines.

Back

Preview of the back of card 4

Card 5

Front

Rocky coasts result from a geology that is resistant to the erosvie forces of the sea and the weather in high energy enviormnets. Coastal plains are found in areas of low relif and depend on the supply of terrestrial sediment.

Back

Preview of the back of card 5
View more cards

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Coastal environments resources »