Geography is easy | Free Online Resources for Geography



Unit 2: The Natural Environment Section A-Topic 1 Coastal Landscapes1- OutlineA- Processesa Types of wave: constructive and destructive.?Describe the characteristics of the two wave types. ?Explain their impact on beach profiles.b Types of weathering, erosion and mass movement on the coastline.?Define and explain the different types of weathering, erosion and mass movement.B- Landformsa Landforms of erosion: cliffs and wave-cut platforms, headlands and bays, caves, arches, stacks and stumps.?Describe the named landforms.?Explain their formation in terms of sequence and the processes involved, including the influence of vegetation and geology.b What is the process of longshore drift? The impact of longshore drift?Describe the process of longshore drift.?Explain the impact on the coastline in terms of landforms and related issues, e.g. deposition in estuaries.c- Landforms of deposition: How are beaches, spits and bars formed?Describe the named landforms and explain their formation in terms of sequence and the processes involved.C- Coastal Recessiona Differential rates of cliff recession due to factors such as fetch, geology and coastal management.?Define cliff recession.?Explain the factors that cause cliff erosion – wave action, weathering and mass movement.b The effects of coastal recession on people and the environment.?Describe the effects of coastal recessions on humans, e.g. insurance and loss of homes.?Describe the effects on the environment, e.g. loss of land.D- Coastal flooding: Prediction and prevention of the effects of coastal flooding by forecasting, building design, planning and education.?Briefly consider what coastal flooding is and what causes it. Factors which increase vulnerability?Identify how the effects of coastal flooding are reduced through planning before the event.E- How the coast is managed.a The types of hard and soft engineering used on the coastline of the UK, and the advantages and disadvantages of these techniques.?Define hard and soft engineering.?Describe hard and soft engineering techniques used in the UK, including groynes, sea walls, off-shore reefs, riprap, revetments, beach replenishment, managed retreat and cliff regradingb How the coast is managed in a named location.?Describe how the coast is managed in a named location.?Consider the costs and benefits of different approaches to protecting the coast in a named location.2- Learning through past questions and the question catcher!A- Processesa Types of wave: constructive and destructive.?Describe the characteristics of the two wave types. January 2011Outline the characteristic features of a destructive wave. You may use a diagram in your answer. (4)Destructive – high frequency 10-14 per minute, short wave length, plunging, high energy/above 1m/backwash>swash (1) therefore beaches eroded (1) High energy waves (1) due to greater fetch (1) Credit labels on the diagram. Max 2 for a list.June 2011Compare the characteristics of constructive and destructive waves. (4)Max three without comparative statements. Max 2 if only reference to one of the requiredelements. Factors to include e.g. swash/backwash, frequency, energy, wavelength, period etc. Allow contrasting as well as comparative comments. E.g. Destructive waves have a greater backwash than swash (1) compared to constructive waves due to their higher energy (1) meaning that they can erode beaches (1). Constructive waves have a lower frequency (1) as a result of their longer wavelength (1) Destructive waves are plunging whereas constructive are surging (1). Destructive waves are higher (>1m) compared with constructive (1). ?Explain their impact on beach profiles.Constructive wavesDestructive wavesProcessGreater swash than backwash. Sand and shingle moved up the beach = depositionGreater backwash than swash. Most material is carried downward by the backwash= erosionImpact on beach profileSediment is being added to the beach which the backwash cannot entirely remove, producing a gentle build-up of beach material. This will increase the gradient of the beach in its lower section. (swash zone)Due to erosion, beach profile becomes gentler in its lower section. (swash zone)b Types of weathering, erosion and mass movement on the coastline.?Define and explain the different types of weathering, erosion and mass movement.Sample paper 1Describe how mass movement causes cliffs to retreat. (3)Mass movement could be rockfall/slumping/sliding/flow (1). Any one process described, eg ‘rocks loosened by weathering (1) and then fall by gravity’ (1). Any other process identified (1).June 2011Outline the process of slumping.(2)Slumping - a rotational movement of land at the coast (1), triggered by saturation (1)State one impact of slumping on the coast.(1)Loss of land (1) Destruction of property/infrastructure (1)Loss of animal habitats (1) Causes coastal recession (1)January 2012Explain the process of physical weathering.(3)Freeze thaw – diurnal changes in temperature around 0 degrees (1). Water in crack widened due to freezing (1), 9% volume increase (1) thawing leaves crack prized open – removes water (1), process repeats (1)Outline the three types of weathering. Physical weathering: the rock is broken apart without any change to the minerals which form it, e.g. freeze-thaw weathering.Chemical weathering: decomposition of rock [change in composition] by biochemical processes, e.g. carbonates in limestone are dissolved by weak acids in rain water.Biological weathering: breakdown and/or decomposition of rock due to the chemical and/or physical agents of an organism [plants or animals], e.g. the roots the trees put out force their way into cracks and, in time, can break up rocks.Explain the process of soil creepOutline the processes of coastal erosion.See textbook page 43B- Landformsa Landforms of erosion: cliffs and wave-cut platforms, headlands and bays, caves, arches, stacks and stumps.?Describe the named landforms.?Explain their formation in terms of sequence and the processes involved, including the influence of vegetation and geology.Sample paper 1Explain how a wave-cut platform is formed. You may use a diagram to help your answer. (4)Explanation to include four points given from: Retreat of cliff (1), through wave erosion (1), with processes such as hydraulic action and Abrasion creating a flat or gently sloping bench (1), often at foot of cliff (1), extending out to sea (1), covered at high tide (1), modified by erosion and/or weathering (1).January 2011Explain the formation of cliffs and wave-cut platforms. Use an annotated diagram or diagrams in your answer. (4)Max 2 marks for descriptive points. Credit explanations at 1 mark each. Max of 3 marks without a mention of process. Full sequence needed for full marks. Max of three without annotated diagram. Cliff formation – sea erodes base of cliff via Hydraulic Action, Abrasion (1). Creation of a wave cut notch and overhang (1) Lack of support (gravity)of overhung cliff creates pressure/cracks and subsequent collapse (1) Action of sea compacting rock into platform which protects coast at low tide (1) Formation of steep cliff which over time recedes (1)January 2012Explain the formation of headlands and bays. You may use a diagram(s) in your answer. (4)Maximum 2 marks for description. Explanations credited at 1 mark each. Max 3 marks without a process or full sequence. E.g. Differential erosion due to perpendicular geology (reference to hard and soft geology which is perpendicular to the coast). Harder rock is more resistant therefore forms land which sticks out into the sea (headlands).Softer rock is eroded (hydraulic action/abrasion/corrosion) at a quicker rate to form a bay. An extension to sequence could refer to development of headlands into stacks/stumps or beaches within bays. June 2012Explain the formation of a stack. You may use a diagram(s) in your answer. (4)Max 2 without explanation. Max 3 without reference to process Max 3 without full sequence. Credit description and explanation on the diagram(s)E.g. Stacks begin as part of an eroding headland. Wave refraction causes waves to attack the side of the headland. Joints are exploited by erosion (named process e.g. hydraulic action, corrasion). Repeated erosion causes a cave, which becomes eroded through to become an arch. Pressure on the arch and force of gravity ultimately cause the collapse of the arch, leaving a stack.For 4 – sequence or named processb What is the process of longshore drift? The impact of longshore drift?Describe the process of longshore drift.January 2013Outline the process of longshore drift. (3)Longshore drift (LSD) is the movement of material along the beach (1). It occurs in the direction of the prevailing waves (1). It is comprised of swash – where breaking waves move material up a beach (in the direction of prevailing wind/waves (1), and backwash – where (due to gravity) material is dragged back towards the sea (1). Swash and backwash is repeated leading to movement in a zig-zag movement along beach (1).?Explain the impact on the coastline in terms of landforms and related issues, e.g. deposition in estuaries.The movement of materials along the coast:- makes boulders and pebbles smaller and more rounded.- creates landforms such as beaches, spits and bars. - is a problem in river estuaries. Some estuaries which are used to harbour boats have to be constantly dredged because of longshore drift depositing material.c- Landforms of deposition: How are beaches, spits and bars formed??Describe the named landforms and explain their formation in terms of sequence and the processes involved.Sample paper 2Explain how a bar is formed. (4)Max 2 marks for descriptive points. Credit explanations at 1 mark each. Max of 3 marks without a mention of process. Full marks can only be achieved if there is a clear sequence of events.A bar is a long, narrow stretch of pebbles and sand (1) which grows across a bay (1) attached to the land at both ends. (1) It forms when longshore drift occurs on a coastline. (1) When the coastline ends, the sea deposits the material it is transporting because the change in depth affects its ability to transport the material further. (1) Can get marks without longshore drift. If a spit develops in a bay, it may build across it, linking two headlands to form a bar. (1) This is only possible if there is a gently sloping beach (1) and no river entering the sea, (1) because the sand will be removed faster than it can be deposited. (1)June 2011Explain the formation of a spit. Use a diagram(s) in your answer. (4)Maximum 2 marks for description. Explanations credited at 1 mark each. Max 3 marks without a process or full sequence. Max 3 without suitable diagram. E.g. Spit – Movement of material along a coastline due to LSD. Occurs where there is a change in direction of the coastline. Over time build-up of spit as more sediment is deposited offshore. May curve at end due to action of wind/waves. Formation of salt marsh due to spit protecting area from wave action.June 2012(i) Describe the spit shown in Box 1. You should only use evidence from Figure 1b. (2)Runs parallel to coastline (1) Approximately 2km long (1) (accept 1.7 – 2.3Km) Describe direction of spit (1) N to S Is approximately 1km wide (1) (accept 0.7 – 1.3) It runs in a straight line (1) Extends south beyond coast (1)(ii) In Box 2 on Figure 1b draw a labelled diagram to show how the spit may change in the future. On your diagram label the direction of longshore drift. (3)Max 1 if not labelled Max 2 if no line of longshore drift. Changes should represent a realistic change to the feature. E.g. May show extension of the spit (1) an area of marsh land behind the spit, (1) curvature of the spit,(1) or repositioning of the spit,(1) or even erosion of the spit.(1) LSD should be from top to bottom (N to S)(1)Explain the formation of beachesArea of land between the low tide and storm tide marks. Made up of deposited sand and pebbles. Formed by constructive waves. Often in bays, where waves have less energy due to gentle sloping land. Along straight stretches of coastline where longshore drift occurs. C- Coastal Recessiona Differential rates of cliff recession due to factors such as fetch, geology and coastal management.?Define cliff recession.When the coast is eroded and retreats.?Explain the factors that cause cliff erosion – wave action, weathering and mass movement.Sample paper 1Explain how rock type and the fetch of waves influence the rate of erosion of cliffs.(4)Rock Type: Softer (1), so easier to erode (1), easier to weather (1). Jointed (1), so easier to erode (1), easier to weather (1). Allow either rock type for maximum 2 marks.Fetch: Longer distance waves have more energy (1), more power to erode (1), increasing hydraulic action/abrasion (1). Maximum 2 marks.Sample paper 2Explain how the type of rock and structure can affect the rate of coastal erosion. (4)Rock type - if the cliffs are made from resistant rock, (1) like granite, (1) they will erode more slowly than cliffs made from less resistant rock, (1) such as clay.Rock structure - the rock’s structure can also have an effect on the rate of erosion. Rocks that are well jointed (1) or with many faults, (1) such as limestone, (1) will erode more quickly (1) as the waves exploit these lines of weakness. (1)June 2010Explain the factors affecting the rate of coastal recession. (4)Can refer here to Geology/Fetch/Coastal Management, mass movement. Expect reference to softer geology increases rates of coastal recession (1) due to lower resistance to erosional impact of waves (1) or Increased fetch increases recession (1) due to more distance for greater build-up of wave energy (1).Case study: Happisburg (North Norfolk coast)Village of Happisburg (population= 850)Factors which explain high rates of erosion in this area:Geology: Cliff made of soft rock (clay, gravel and sand deposited by glaciers)No sea defences: 1958: use of revetments to reduce coastal erosion. From 1995 no repairing of coastal defences high rates of ernment has refused to protect the village because it is not cost effective: the village is less valuable than the cost of the defences to protect itJanuary 2011Explain how variations in the length of fetch and the geology might increase the rate of coastal recession. (4)Max 2 without explanation. Must refer to both geology and fetch, i.e. max 3 for either fetch or geology.Fetch – Larger fetch results in larger waves (1), therefore the approaching waves have more energy to erode (1) thereby increasing coastal recession (1). Geology- Softer rock will provide less resistance (1), therefore increasing the impact of the wave energy (1) therefore increasing coastal recession (1). Increased fetch causes greater potential for erosion (1), as wind can build bigger waves over a larger stretch of water (1).b The effects of coastal recession on people and the environment.?Describe the effects of coastal recessions on humans, e.g. insurance and loss of homes.Sample paper 1Explain how cliff erosion can affect the economy of the local area. (4)Explanation to include four points given from: Loss of property/land (1), increase insurance issues (1), loss of businesses (1), costs of closing beaches (1), any other legitimate explanation (1). Only allow to 4 marks if links to economy (i.e. loss of income or wealth) established.Case study: Happisburg (North Norfolk coast)Loss of homes: Since 1995: 25 properties and the village’s lifeboat launching station washed away.Loss of value: Houses worth ?80,000 when the coast was defended, are now valued at 1?. No insurance of property against coastal erosion.Loss of business: Over the next 100 years: 1400 caravan and chalet parks, six hotels and guest houses. Seven historic buildings and seven golf course holes will be lost to the sea. ?Describe the effects on the environment, e.g. loss of land.Sample paper 2Explain the effect that coastal erosion has on people and the environment. Use examples in your answer. (6)Effects such as:? cliffs crumble and actual recession per year? farming land lost such as …? animal habits destroyed such as …? houses fall into sea such as …A range of specific facts relating to the effects on people and the environment and explained points.Effects on the environment: Case study: Durlston BayLoss of land:At Durlston Bay near Swanage the cliff receded 12 metres between 1968 and 1988. In 200/01 severe storms and high energy waves led to a further retreat of another 12 metres.Loss of natural habitatsDurlston County Park also lies on the top and is home to over 250 species of birds that nest on the cliff. These habitats are threatened by cliff recession, which can affect the breeding of rare species such as puffins and falcons.Effects on people: Case study: Happisburg (North Norfolk coast)Loss of homes: Since 1995: 25 properties and the village’s lifeboat launching station washed away.Loss of value: Houses worth ?80,000 when the coast was defended, are now valued at 1?. No insurance of property against coastal erosion.Loss of business: Over the next 100 years: 1400 caravan and chalet parks, six hotels and guest houses. Seven historic buildings and seven golf course holes will be lost to the sea.January 2011Explain the effects of coastal recession on people and the environment. Use examples in your answer. (6) A range of specific facts relating to the effects on people and environment and explained points.D- Coastal flooding: Prediction and prevention of the effects of coastal flooding by forecasting, building design, planning and education.?Briefly consider what coastal flooding is and what causes it. Factors which increase vulnerabilityCoastal flooding occurs when normally dry, low-lying land is flooded by sea water. Causes of coastal flooding:Severe weather: Strong winds and storms which can increase the height of waves and tides. Storm surge: A storm surge is an offshore rise of water associated with a low pressure weather system*, typically tropical cyclones. Storm surges are caused by high winds pushing on the ocean's surface. The wind causes the water to pile up higher than the ordinary sea level.*A low-pressure area, low or depression, is a region where the atmospheric pressure is lower than that of surrounding locationsSea level rise: Coastal flooding associated with sea level rise will become a significant issue into the next 100 years.. Factors which increase vulnerabilityTides, low-lying land, and property built on low-lying land.?Identify how the effects of coastal flooding are reduced through planning before the event.Sample paper 2Coastal flooding can be predicted. Justify this statement. (3)As well as the monitoring which is being done by the Met Office, the Environment Agency also monitors sea conditions over a 24 hour period, 365 days a year. The Storm Tide Forecasting Service provides the Environment Agency with forecasts of coastal flooding which the Environment Agency communicates to the public via their website or phone line.June 2010Explain how coastal flooding can be reduced through planning and forecasting. (4)Planning: Not allowing homes to be built in potential flood-risk zones. Reference to government planning laws. DEFRA to decide which areas of coast need planning to prevent areas at most risk therefore reduce the impacts of flooding.Forecasting: Improved forecasting (to households through broadcasts) enables prediction of conditions at sea, therefore give warning of possibility of coastal flooding and allow measures to be taken to act against the risk of flooding. Expect ref to Met Office/Environmental Agency.1 mark for outline, 2 for explanation of how factor reduces coastal flooding. 1 point could be developed to full marks as long as planning and forecasting are present. Max 3 for either planning or forecastingJune 2011Explain how the effects of coastal flooding are reduced. Use examples in your answer. (6)Methods to reduce the effects of coastal flooding, e.g. forecasting systems, building design, land-use planning and education. Specific means something like the name of a scheme, a date or a numberJanuary 2012Explain how the effects of coastal flooding can be reduced through prediction and prevention. Use examples in your answer. (6)January 2013Describe how building design and planning can reduce the effects of coastal flooding. Use examples in your answer. (4)Max 3 if only building design or planning Max 3 if no located examples, either country (e.g. Bangladesh), or region / specific place. But no specific credit actual example. Building design – homes on stilts, waterproofing measures Planning – land use zoning; allow referenceto defence if linked to planning, evacuation (e.g. monitoring by Environment Agency).Allow forecasting as part of planning. E.g. In LICs coastal homes in areas prone to flooding are designed with stilts (1). Therefore when flooding occurs possessions are not destroyed as the water is able to pass below the home (1).Case studies: The UK and BangladeshE- How the coast is managed.a The types of hard and soft engineering used on the coastline of the UK, and the advantages and disadvantages of these techniques.?Define hard and soft engineering.Soft engineering: method of coastal management which works with natural processes at work on the coastline and to be unobstructive (unnoticeable) visually. It does not involve major construction.Hard engineering: method of coastal management which involves major construction work.?Describe hard and soft engineering techniques used in the UK, including groynes, sea walls, off-shore reefs, riprap, revetments, beach replenishment, managed retreat and cliff regradingJanuary 2011Groynes protect cliffs from erosion. Explain how. (3)These groynes prevent LSD (1) therefore trapping sediment (1), thereby building a beach (1) This beach will absorb the wave energy and reduce erosion (1) Must have reference to erosion for 3rd markJanuary 2012Soft engineering is a way of managing the coastline. Outline the advantages and disadvantages of soft engineering techniques. (4)Outline required.Credit explanations at one mark. Max 3 with reference to only advantages or Disadvantages Advantages – cheaper than hard engineering (1). More sustainable to environment (1), and does not require quarrying of rock (1). Less visually obtrusive (1). Doesn’t require as much maintenance. Disadvantages – less effective than hard engineering (1) as it does not always stop erosion from occurring (1), cost of maintenance could be high in the long term (1) with repeated outlays due to annual upkeep (1)January 2013Explain the advantages and disadvantages of offshore reefs as a method of coastal defence. (4)Max 2 for just a description. Max 3 without reference to both advantages and disadvantages.Advantages: They do not take up space on the coastline (1) therefore do not directly affect developments (1) They break waves before they reach coast (1) Reduce wave energy before it reaches the coast(1) meaning less need for onshore protection (1) Visually unobtrusive (1) Long lasting / value for money over time (1). Disadvantages: Local residents may be upset during construction (1) The cost of set up is high / maintain (1) They are not always effective in intense storms (1) therefore may need secondary support on the coast (1) There may be environmental concerns / damage habitats / ecosystems (1).Advantages and disadvantages of other methodsSee book p58 and 59. Add revetments to hard engineering methodsb How the coast is managed in a named location.?Describe how the coast is managed in a named location.?Consider the costs and benefits of different approaches to protecting the coast in a named location.Sample paper 1, For a coastal area that you have studied explain the varied methods used to manage the coastline. (6)Depends on case study but likely to include:-other types of hard engineering – sea-walls etc.- soft engineering such as beach replenishment- managed retreat or do nothing approaches- method chosen depends on needs of area/section usually determined by economic value of that area/section.There is a good explanation of the chosen methods. Answer has detail of own case study which can be clearly related to the variation of methods used. Well communicated with good use of geographical terminology, spelling, punctuation and grammar.June 2010/June 2012/ January 2013Choose an area of coast you have studied. Explain how this area of coastline has been managed.(6) A range of specific facts and explained points about how the coast has been managed.Case Study Swanage In Dorset on the south coast of EnglandIn Durlston Bay, erosion mainly occurs at one particular point, where there was a major weakness in the resistant limestone rock. There were three methods used to protect the cliffs from erosion (recession): Cliff regrading – extending it forward, making slope longer and less steep. Reduces the risk of mass movement. Drainage – removing excess water, so slope wasn’t as heavy or lubricated after rain. Reduces the risk of mass movement and freeze-thaw weathering. Rip rap placement – Large boulders at the base of the cliff to resist wave attack and dissipate wave 21energy.Swanage BayThis is a popular recreational area for beach users, diving, fishing and sailing. Erosion occurred along a considerable length of cliff. SEA WALL? Built in the 1920s and provided a promenade as well as a barrier to wave attack. The most cost effective method was found to be the replacement of the 1930s groynes and replenishment of the beach sediment. A series of mainly timber groynes were installed in the 1930s, and eighteen of them have been replaced in 2005 with new ones. These reduced longshore drift and help make sure that a beach remained in place to absorb the energy of breaking waves. Beach replenishmentIn November of 2005, 90,000 m3 of sand was deposited on the beach. The beach will need to be recharged with around 40,000m3 of sand every 20 years. This works with the groynes to ensure a good size beach. The works were finally completed in June 2006at an estimated cost of ?2.2 million. Cliff regarding: A series of steps were made in the cliff to reduce slope angles Coastal management issues: 1- The potential impact of any coastal defence works on Swanage tourism and the aesthetic and landscape quality of the coastline.2- The cost of protecting the coast3- The efficiency of the methods used: In January 1st, 201 3, Dorset Coastguard have restricted access to Swanage beach and the South West Coastal Paths, after heavy rains over the holiday period caused further mudslides and cliff subsidence in Swanage. ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download