Unit 2: 4- Coastal change and conflict

Question 1

How are rocks brocken down by Mechanical weathering? What is mechanical weathering?

Answer 1

Mechanical weathering-. breackdown of rock without chage to it’s chemical composition mainly salt weathering at coast
1. Saltwater gets into cracks
2. When water evaps salt crystal form as the crystal expand preasure is put on rock
3. This evap repeats= forming onf crystals widens cracks = crystalas widen cracks causing the rock to break up

Question 2

How are rocks brocken down by Chemical weathering? What is Chemical weathering?

Answer 2

**Chemical weathering **-> Breakdown of rock by changing it’s chamicla composition. Carbonation weathering is type wich happens in warm wet conditions.
1. Sea water + rain water have CO2 dissolved in them = weak carbonic acid
2. Carbonic acid reacts with rock wich contains calcium carbonate e.g. carboniferous limestone so rocks are dissolved by rainwater

Question 3

How are rocks brocken down by Biological weathering? What is Biological weathering?

Answer 3

**Biological weathering **-> Breakdown of rock by living things
-> plant roots break down into rocks by growing into cracks in surface pushing them apart

Question 4

What is mass movement? Describe the process.

Answer 4

Mass movement-> Shifting of rocks and lose materials down a slope e.g. cliff happens when force of gravity acting on a slope >than the the force supporting it
-> causes the coast to reatreat rapidly
->More likley to happen in saturated soil ( full of water) as it acts as a lubricant making material heavier

Question 5

What are the 4 types of mass movement?

Answer 5

Question 6

What are the 3 types of costal erosion? Define them.

Answer 6

Hydraulic power-> Waves crash against the rock and compress ai rin cracks putting preasure on rocks. Repated compression widens the crack and makes more peices break off.
Abrasion-> eroded particles in water scrape and rub against rock removing small pieces.
Attrition Eroded particles in water smash into each other and break into smaller fragments. Edges get rounded off as they rub toghether

Question 7

What are joints/faults?cracks and how do they effect the resistance of the rock?

Answer 7

Joints/Faults/Cracks-> weaknesses in the the rock. more joints ect means less resistant to erosion

Question 8

What is a disocordant coastline? What erosional landforms are found there?

Answer 8

Coastlines made of alternating bands of hard and soft rock running at right angles ( perpendicular) to coast
Erosional landforms:
Bays and headlands: bands of rock are being eroded at diff rates
=> softer rock erodes faster =bay= gentile slope
=> Harder rock erodes slower = headland= sticks out has steep sides

Question 9

What are concordant coastlines?

Answer 9

Alternating bands of hard + soft rock are **parallel ** to coast
Erosional landforms:

Question 10

How does the UK’s climate influence coastal erosion?

Answer 10

• Mild temp increase salt weathering ( increase the rate of evap)
• Storms creat:
  -> Strong winds=high energy destructive waves increasing erosion
  ->Intense rainfall= saturated clifs =mass movement
• Prevaling wing + warm south Westerlies form atlantic ocen= south coast ecposed to these winds
• Cold notherlys common espacially on east coast.

Question 11

What are destructive waves? How do destructive waves wear away the coast?

Answer 11

Destructive waves-> High( tall),steep and high frequency (10-14)
* They carry out erosinal processes
* Backwash> than the swash-> water removed form the coast
* Storms increase the erosinal power of destructuve waves which lead to increased rates of coastal erosion

Question 12

Describe how headlands can be eroded to form caves arches and stacks.

Answer 12

Headland made of resistant rock thta has weaknesses and cracks
1. Waves crash into headlands and enlarge cracks by hydrolic action + abrasion
2. Repeated abrasion + erosion = cracks form=>cave
3. Continued abration =deepens cave till it breaks through headland =>Arch e.g. dundle door dorset
4. Erosion contines to wear away rock supporting arch untill it collapses=> stack
5. Stack= isolated rock seprate form headland e.g. old harry dorset

Question 13

What is transportion and what specifically along the coast is it called?

Answer 13

Transportation-> Movement of materials
Long shore drift-> is the movment of materials along the coast( type of transportation).

Question 14

What is a constructive wave?

Answer 14

• Deposit more than they erode
• Low, long and low frequency (6-8)

Question 15

**

Describe the process of Long Shore Drift.

Answer 15

1. Waves follow dirction of the prevaling wind
2. Usally hit coast at Oblique angle ( any angle witch isn’t 90)
3. Swash carries material up beach in same direction as waves
4. Backwash carries material down the beach at right angles towards sea
5. This forms zigzag pattern along beach

Question 16

Describe the formation of a spit.

Answer 16

• Form at sharp bends in coastline e.g. river mouth
• LSD transports sand +shingle past the bend and deposots it in to sea,
• Strong winds and waves curve the end if the spit=> forming a recuved end
• The sheltered area behind is protected from the waves= lots of material accumulates= plants can grow.
• Over time sheltered area=> mud flat or salt marsh

Question 17

Describe the formation of a Bar.

Answer 17

1. A bar is formed when a spit joins 2 headlands togetheer
2. The bar cuts off the bay between the headlands form the sea.

Question 18

What effect has Agriculture had on the UK’s coast?

Answer 18

• Agricultural land = low econmic value= often unprotected=> direct effect as sea can erode cliff and shape land.
• Changing the use of farmland affects the stablity of the cliffs:
  ->Vegatation- Helps bind the soil together and stablise the clifftops. Clearing veg from grazing land to make room for crop = expose the soil + underlying rock = vonerable to weathering by wind + rain ( soil erosion)
• Land e.g. marsh land sometimes reclaim and drained for agricultural use draining marsh land = direct effect on the nature as it act as flood barrier

Question 19

What effect has Development had on the UK’s coast?

Answer 19

• Costal area= popular palces tot live work ect= lots of devlopment e.g. hotels and infastructure
• Coast with lots of sttlement= more defoences as peoeple whant to defend homea nd businesses. Direct poitive effect on coast = better protected agianst erosion.
• Indirect effec onf developement :change intransportaion and deopsition. Buildings in coastal lowlands= restrit sedment supply to beaches = narroewer which don’t protect the coast as well= more vonerable

Question 20

What effect has Industry had on the UK’s coast?

Answer 20

• Coastal quarries expose large areas of rock= more vonrable to erosion + chemicla weathering
• Gravel has been extracted from some beaches in use for the construction inductry e.g. concrest production. This removes material form coast increasing the risk of erosion as there is less material to protect cliffs.
• Inducstial growth at ports= increases preasure to build on salt marshes wich are areas which provide flat land and sheltered water ideal for ports and industry but are natural flood barriers. Building on them= vunerable to erosion

Question 21

How does rising sea levele increas the risk of flooding?

Answer 21

• Threat to lowlying coastal areas
• Could cause higher tides wich would flood coastal areas more frequently
• Higher tides could remove more material form beahces => increased erosion of cliffs because there is less material to protect them for the sea.
• More cosat could be exposed to terosion beach coul beocm more noarrow as the sea is able to move more inland.

Question 22

How does storm frequency increase the risk of flooding?

Answer 22

• Climate change is causing an increas in storm frquency.
• Storms give sea more erosional power areas od hard rock = more vonerable to erosion, soft rock will erode more quickly
• Sea will have more energy to transpor tmaterial. high energy waves can move more matrial for greater distances may lead to some areas being starved of materialleaving them vunrable to eroion +flooding.
• Increase sea level + storm Surge = storm can reach futher inland

Question 23

How do the effects of climate change theaten people?

Answer 23

• Low lying costal area = permainaltly flooded= inhabitable
• Costtal industry shut down due to the damage to equitment and buildingd e.g. destruction of fishing boats
• Risk of damaging infastructure road rail networks ect
• Flooding + erosion can deter torists= loss of livelihoods

Question 24

How do the effects of climate change theaten the envirment?

Answer 24

• Ecosystems affected due to the seawater with high salt content. Increased salt leveles due to coastal flooding can damge or kill organisma in ecosystem. Can effect agricultural land by reducing soil fertility
• Force of floodwater can uproot trees + plants and standing floodwater drowns some trees and plants.
• Some conservation areas are threatened by coastal erosion e.g. LAgoons on holdenress coast that arnt protected if bar erroed lagoon could be destroyed

Question 25

Define hard enginering

Answer 25

Man made structure buit to control the flow of sea and reduc eflooding + erosion

Question 26

Define sofr enegrnering

Answer 26

Schemes set uo usinf knowalage of sea and it’s process to reduce effects of flooding and erosion

Question 27

What is a sea wall? Is it hard or soft engineering? What are it’s benfits and costs?

Answer 27

Sea walls-> Wall made of hard material like concret that reflects waves back to sea
Hard engineering
+Prevents erosion
+ acts as flood barrier
-Creats strong backwash =erodes under the wall
-Very expensive to build + maintian.

Question 28

What are Groynes? Is it hard or soft engineering? What are it’s benfits and costs?

Answer 28

Groynes-> Wooden or stone fences that are built at right angles to coast. Trap material transported by LSD.
Hard engineering
+Create wider beaches wich slow wves= greater protection form flooding and erosion
+faily cheap
-Terminal gryne syndrome making beashed futher down starved of sedment narrwong leading to flooding + erostion

Question 29

What is Beach replenishement ? Is it hard or soft engineering? What are it’s benfits and costs?

Answer 29

**Beach replenishemnet **-> Sand + shingle form elsewhere ( e.g. seabed) or lowe down beach added to upper par of beach.
Soft engneering
+Creates wider beaches wich slow the waves
+ greater protection form flooding + erosion
-Taking material for seabed = kill organisms like coral
-very expansive
-Has to be repeated

Question 30

What is slope stableisation? Is it hard or soft engineering? What are it’s benfits and costs?

Answer 30

Slope Stabilisation-> Slopes reenforced by inserting concret nails into ground and covering slpe with metal netting
Soft engineering
+Prevents mass movment via increasin slope strenght
-Very expensive
-Sometime very difficult to install

Question 31

What is strategic realignment? Is it hard or soft engineering? What are it’s benfits and costs?

Answer 31

**Strategic realighment **-> Removing exsisting defneces allowing land bhind to flood
Soft engineering
+ over time land will become marchalnd- creating new habitiatat
+ Floodign + erostion are reduced behind mamarshland
-May be disagreements on what aland is allowed to floood e.g. farmland

Question 32

WHat are the 3 coastal stratiges

Answer 32

1. Hold the line
2. Advance the line
3. Do nothink

Question 33

What is the ICZM

Answer 33

Intergarated Coastal Zone Management -> an approch wich aims to protect coat while taking in veryones intrests
-> e.g. making it sustabloe for future Gend intrests