Geography Controlled Assessment 2015 GCSE Edexcel A

Transcription

1 Geography Controlled Assessment 2015 GCSE Edexcel A Name: Class:.. Teacher:

2 An introduction to Unit 4 - Controlled assessment: Unit 4 of the specification is different to the other units because you do not have to do an examination which is marked by examiners. It is an internally assessed piece of work known as controlled assessment. Controlled assessment is worth 25% of your final examination mark which is the same as the other three units. Therefore it is very important that you perform to the best of your ability in this section of the examination! Your work should take the form of an investigation with chapters on the different sections of the controlled assessment. It will be marked by your teacher and some of the pieces of work will be sent to a moderator who has been appointed by Edexcel. Your teacher will give you guidance on how long to spend on each section of the work but this will be flexible because we all work at different speeds. The word limit is 2,000 words (plus or minus 10%) so try not to get carried away. The assessment will be carried out under controlled conditions. You will be supervised to make sure that the work is entirely your own. The exam board have produced the mark scheme for this enquiry; your teacher will ensure that you understand how you will be assessed. You need to collect fieldwork data to answer the assessment question. Minster Cliffs (date unknown) (Source: Minster Cliffs 1962 Minster Cliffs today

3 Title: Investigate the differences between two or more contrasting landforms along your chosen stretch of coastline. Student Guidance The route of enquiry: We will be investigating the coastline of the Isle of Sheppey. The two coastal landforms we will be analysing will be beaches and cliffs. You will visit two coastal sites along the coastline of the Isle of Sheppey. The first site is at Barton s Point, and the second site is further down the coastline at The Lea s and Minster cliffs. Both sites are located in the county of Kent and are on the coastline in the North Sea. You will collect primary data during your visits to these sites. You will also have access to a range of secondary data to help you compare the landforms. It is suggested that you use the following to structure your written report. 1) Title Page Controlled assessment question, name, class, teacher 2) Contents Section titles and page numbers. 3) Aims What are your aims of the investigation? What are you comparing? What do you hope to find out? 4) An Introduction Use this to set the scene. Where is this assignment located? What are the geographical features of the area (both human and physical)? Why might coastal management be necessary? What is the variation of coastal landforms at these sites? Which of these will you be investigating? What might the reasons be for differences at both sites? What geographical theories will you be linking your enquiry to (rock type, wave type, depositional processes, and erosional processes)? Fieldwork: Field visits will be made to Barton s Point and the Lea s/ Minster Cliffs. This is when you will collect your primary data. 5) Data Collection and Analysis You will use a range of primary data to investigate the differences to beaches and cliffs at both sites (Methods of data collection will be looked at later in this information pack).

4 Within your account you should include graphical evidence (annotated photos and field sketches) and statistics from your survey sheets & cliff diagrams (please refine and graph the statistics). In order to gain access to the highest levels in the new specification mark scheme, you will need to show some type of independent thought/approach to their data collection and work. It would be advisable to devise your own annotation for field sketches and labels for your collected results. Select any additional supporting evidence from the secondary materials you have. Please credit the source of each selected item, including the date it was accessed, and say why you have included the material. Research and data collection: You will be allowed hours for this. Here you will collect additional data from secondary sources using the Internet; you will begin to process and refine your data (e.g. annotate photos, graph statistics etc.); explore ways to structure your task as well as find links to work you have covered in class on Physical Geography (Physical Processes and Relationships). You will compare your results from the primary data collection at the two sites. You will have choice about how to present your data. For example, you may draw your graphs by hand or using a computer. You will be allowed to share data with others and you may ask your teacher for advice about how best to organise your work. You will have your own research folder to keep all ongoing work in - this will be looked after by your teacher as you will be using the contents of it for final phase. The folder with all of your work MUST be handed in at the end of each lesson. 6) Analysis of data What is the data that you are using and why you have used this data? How is it linked to relevant theory? How it is linked to the question - Investigate the differences between two or more contrasting landforms along your chosen stretch of coastline. You must analyse your data i.e. compare the two sites and link to theory. 7) Conclusion What do your results show? What are the links to the theory? Have your results highlighted anything significant to you e.g. are there dramatic differences? Why is this? What needs to be done? What problems might be caused? 8) The Evaluation If you had unlimited time and resources how might you improve your enquiry? Outline the strengths and weaknesses of the primary and secondary data that you used as evidence. Were

5 your results valid? Could they be replicated? If you did the coursework again, what would you differently? How would you improve the validity of your results? Recap: Coastal Landforms: Task 1: How is a beach formed? Keywords: Transported, deposited, constructive Task 2: How are cliffs formed? Include a diagram. Keywords: Erosion, weathering, soft/hard rock Diagram:

6 Primary and Secondary Data: On your field trip and in your research lessons you will need to research about the coastline from Barton s point along to Minster Cliffs. You will then have the opportunity to collect primary data. The primary data you collect will include: At least 4 digital photographs at the Barton s point section of the coastline (the cliff face, beach profile and management structures). At least 4 digital photographs at the Leas and Minster cliffs (the cliff face, beach profile and management structures). A field sketch at both sites Beach profile data (to be conducted by individuals at each location). Two cliff surveys (one at Barton s point and at Minster). The digital photographs and field sketches will need to be annotated in your assignment. What can you see on the picture/drawing that helps you analyse the differences at each location? What annotations have you used to support these differences? You will need to use secondary data to help reinforce your ideas about the differences of the landforms at each location. You should use: Your standard textbook for background information on coastal landforms & processes, management of the coastal, and the issues of conflict with decisions made. A range of websites specifically related to the Isle of Sheppey coastline. All websites that are used must be referenced in the text. Primary Data Collection (Source: Royal Geographical Society): Technique one: Beach profiles Aims To survey the shape (morphology) of a beach. To compare beaches or coastlines in different locations. To examine the effects of management on beach processes and morphology. To investigate seasonal changes in the beach profile. To examine relationships between the beach profile and other factors, for example rock type, cliff profile, sediment size or shape. Equipment Tape measure

7 Ranging poles Clinometer Compass Recording sheet Methodology 1. Select sampling points for beach profiles across the width of the beach. 2. At each sample point in turn, place a ranging pole at the start and finish (at A and H on the diagram). Point A should ideally be the low tide mark, or as close to this as is safe. 3. Note the main changes in slope angle up the beach, and use them to inform the sections' for the profile. (A through to H on the diagram) 4. For each change in slope, use the clinometer to take a bearing to record the slope angle (ii). For example, from point A to point B in the diagram below. It is important to ensure that the bearing is taken from a point on the ranging pole that coincides with the eye level of the person using the clinometer. Many ranging poles have stripes which can be used for this purpose. Alternatively, bearings can be taken from the eye level of a person of a similar height holding the ranging pole. 5. Measure the distance along the ground of the section (i), and record this information alongside the slope angle. 6. Repeat processes four and five for each break in slope that you have identified. Figure one: Surveying the morphology of the beach using a clinometer and ranging poles. Data collected using this technique can be used to create beach profiles. Pantometers can be used by one person, and the slope can be surveyed systematically at regular, short intervals.

8 Figure two: Using a clinometer to measure the angle of a beach profile. Considerations and possible limitations Varying tidal conditions can affect access and safety. Make sure you check tide times before you embark on your fieldwork. Low tide is the best time to measure beach profiles, but places a time constraint on the activity. This can be overcome if groups of students complete profiles at different locations simultaneously and share their results. It is important to ensure that the ranging poles are held straight and prevented from sinking into sand, both of which may affect angle readings. Sampling technique is an important consideration. A balance needs to be struck between time available and the need for a number of profiles across the width of the beach to ensure the validity of results. There may be some user error when taking readings with a clinometer, and the sophistication of models of clinometer can vary enormously. Using the data within an investigation Data can be used to draw profiles onto graph paper using distance from sea as the horizontal axis and using an angle measurer to complete the profiles. The graphs can then be analysed and comparisons made across the width of the beach. Profiles can be measured at different locations on the same stretch of coastline or in different seasons and compared. Different stretches of coastline which may have different natural characteristics, for example sand and shingle, or human characteristic, for example managed and unmanaged can also be compared. Beach profiles can be used in conjunction with other data collected to examine relationships between different variables.

9 Technique two: Sediment analysis Aims To examine the sorting of beach material, either across the beach profile (following the sample lines used for profiling) or across the width of the beach (linking to the process of longshore drift). To investigate the effect of management structures, for example groynes, on the sorting of beach material. To investigate the origin of beach material through the study of sediment cells To compare sediment analysis at beaches in a range of locations and attempt to explain similarities and differences. To examine the relationship between beach sediment and other factors, for example the size and slope of the beach. Equipment Clear ruler, pebble meter or stone-board Roundness or angularity charts/indexes Recording sheet Quadrats (optional) Random number table (optional) Methodology Techniques for measuring are the same as for sediment analysis in river studies. Please refer to this section for more information. However, thought should be given to the sampling technique used to ensure that a representative sample is obtained. Quadrats can be used to select sediment for sampling. Alternatively, ten surface pebbles touching your foot can be selected at each location. There are many different methods of sampling sediment. The different methods should be analysed by the researcher and an informed decision made as to which is the most appropriate for the aims of the investigation. Considerations and possible limitations Deciding on the sampling strategy is very important in reducing subjectivity and increasing the validity of results. A sampling method should always be adopted to avoid the temptation to select the pebbles. Sample size should be large enough to provide a representative sample of the parent population', yet not too large to be unmanageable. The sharpest point of a stone must be measured when using the Cailleux scale and judgement of this may vary from person to person creating subjectivity. In reality, using Power's scale will reveal mostly class five/six. Anything which may affect the results should be noted, for example recent storms or management structures which may alter the composition of beach material.

10 Technique three: Measuring longshore drift Aims To examine the transport of material along a stretch of coastline. To compare processes of sediment transport in different locations along the coastline. To investigate the effect of management techniques on the movement of beach material along the coastline. To examine the causes and effects of changes to the dominant direction of longshore drift. 1. Observing swash and backwash, and transport of material Equipment Float, for example an orange or cork Stopwatch Tape measure Methodology 1. Decide on an appropriate distance to measure longshore drift over, for example 10 metres. 2. Lay out tape measure close to water and mark start and finish points. 3. Place your float into water in the breakwater zone at the start point. 4. Observe and time the object's movement across the pre-set distance. Similar results can be obtained if the distance travelled by the object is recorded over a specified time, for example five minutes. Considerations and possible limitations Tidal and wind conditions, the size and weight of float used and the slope angle of the beach may all affect measurements. Take note of the wind speed and direction on the day the fieldwork is undertaken as this may affect the speed at which the float is transported. This is particularly important if further sampling for the investigation is undertaken on another day. Obstructions to the movement of float, for example rocky outcrops, may affect results. Floats may be lost during the investigation. Repeated experiments or the use of more than one marker can reduce this problem. Floats should be placed in the water ahead of the start line to allow them to settle prior to recording, and avoid giving the floats extra momentum. The float should lie low in the water to ensure that it is not influenced by the wind. The measuring should be undertaken in an area where there are no swimmers or paddlers for safety reasons and to ensure the reliability of results. Any anomalies should be recorded, for example obstructions which may affect the movement of the float.

11 Weather and sea conditions can have a dramatic effect on observations. Using data within an investigation Data would not be used in isolation, but in conjunction with other data collected as supporting evidence. Most commonly used when comparing managed and unmanaged stretches of coastline, particularly the impact of management techniques on transport processes within the sediment cell. 2. Investigating the impact of groynes on the movement of sediment Equipment Metre ruler Compass Record sheet Camera Methodology 1. Using the compass, identify and record the aspect of each side of the groyne, for example the western and eastern side of each groyne. 2. Use the meter ruler to measure from the top of the groyne to the surface of the sediment on each side. 3. Take digital pictures to illustrate differences in sediment levels. 4. Repeat for each groyne, or identify and use a suitable sampling strategy if there are too many groynes to sample them all. Considerations and possible limitations Measurements should be taken at the same point along the length of each groyne, and tidal conditions and safety are therefore a consideration when undertaking this fieldwork. Care should be taken to ensure that the metre ruler doesn't sink into the sand, and that it is held straight. Using the data within an investigation The findings of the investigation can be used to study the impact of physical and environmental processes on a stretch of coastline, including seasonal variations or variations in response to weather conditions, for example changes in the prevailing wind direction or storm events. Graphical representation of data can be used to compare sites. The data could be used within an investigation into the impact or success of coastal management strategies. A comparison of different sites could be made, comparing managed with unmanaged sites, or sites managed in different ways. The impact of coastal management

12 strategies on other beaches further along the coastline can also be studied using this method. Findings can be used to label and annotate images, see examples below from Swanage Beach in Dorset. Figure three: Annotated images of the beach at Swanage, Dorset showing evidence of longshore drift.

13 Figure four: Measuring the height of sediment to the west of a groyne Technique four: Cliff surveys Aims To examine physical characteristics and features along a stretch of coastline To identify different rock types and investigate the links between geology and physical features. To compare coastlines with different geologies. To study evidence of coastal erosion, including sub-aerial weathering, mass movement, basal erosion by the sea, human activity. To investigate and analyse strategies for protecting against coastal erosion. Equipment Plain paper, pencil and rubber for sketch Camera Geological guides Secondary evidence, for example photographs, maps, newspaper cuttings Tape measure Clinometer Methodology Cliff height Standing a safe distance from the cliff, measure distance (A) using a tape measure. A distance of around 10 meters may be appropriate, but this depends on the size of the beach. Use a clinometer towards the top of the cliff to measure angle (B). The height of the cliff is calculated as follows: o Distance (A) x tan of angle (B) + height of observer.

14 Figure 5: The method for measuring the height of a cliff using a clinometer. Cliff sketch A detailed sketch of the physical and human features of the cliffs at predetermined sampling points. Once cliff height has been established, the sketch can be drawn reasonably accurately to scale. Observations and annotations should be made of: Obvious features, for example high tide level, caves, wave-cut notch, wave-cut platform, gullying. Basic geology (can be added later). Structure, for example bedding planes and joints, folding and faulting. Conservation considerations, for example nesting birds, other animals. Type of vegetation and any evidence of effect on erosion. Evidence of erosion or mass movement, for example slumping, rock falls. Human activity, for example built structures, management/protection measures, recreational activities. Photographic evidence can also be used to support and reinforce sketches. Considerations and possible limitations Be aware of the safety implications of working close to cliffs, it can be dangerous. It is important to consider the sampling strategy, where to carry out cliff surveys and how many to do - before the investigation is started. There may be some user error when taking readings with a clinometer, and the sophistication of models of clinometer can vary enormously. Using the data within an investigation Cliff profiles can be used in conjunction with other data collected to examine relationships between different variables, for example beach profiles or sediment analysis.

15 An investigation could examine the links between the beach morphology, sediment and cliff features. An investigation could examine the links between the geology of the cliffs and beach material or movement. It is possible to compare different stretches of coastline with different geologies to see how they vary in terms of geology, sediment and beach morphology. Secondary data, for example historical maps, photographs or articles from local newspapers or websites can be used to examine recession rates. Predictions could be made for future rates of cliff recession, alongside suggestions for future management. A study of the range of different techniques used to manage the cliffs could highlight costs and benefits as well as potential impacts on physical processes and human activity. Each technique could be assessed in terms of its effectiveness at reducing rates of recession. Sampling Techniques: What is sampling? A shortcut method for investigating a whole population. Data is gathered on a small part of the whole parent population or sampling frame, and used to inform what the whole picture is like. Why sample? In reality there is simply not enough; time, energy, money, labour/man power, equipment, access to suitable sites to measure every single item or site within the parent population or whole sampling frame. Therefore an appropriate sampling strategy is adopted to obtain a representative, and statistically valid sample of the whole. Sampling considerations Larger sample sizes are more accurate representations of the whole. The sample size chosen is a balance between obtaining a statistically valid representation, and the time, energy, money, labour, equipment and access available A sampling strategy made with the minimum of bias is the most statistically valid. Most approaches assume that the parent population has a normal distribution where most items or individuals clustered close to the mean, with few extremes. A 95% probability or confidence level is usually assumed, for example 95% of items or individuals will be within plus or minus two standard deviations from the mean. This also means that up to five per cent may lie outside of this - sampling, no matter how good can only ever be claimed to be a very close estimate.

16 Sampling techniques Three main types of sampling strategy: Random Systematic Stratified Within these types, you may then decide on a; point, line, area method. Random sampling Least biased of all sampling techniques, there is no subjectivity - each member of the total population has an equal chance of being selected. Can be obtained using random number tables. Microsoft Excel has a function to produce random number. The function is simply: =RAND() Type that into a cell and it will produce a random number in that cell. Copy the formula throughout a selection of cells and it will produce random numbers. You can modify the formula to obtain whatever range you wish, for example if you wanted random numbers from one to 250, you could enter the following formula: =INT(250*RAND())+1 Where INT eliminates the digits after the decimal, 250* creates the range to be covered, and +1 sets the lowest number in the range. Paired numbers could also be obtained using; =INT(9000*RAND())+1000 These can then be used as grid coordinates, metre and centimetre sampling stations along a transect, or in any feasible way. Methodology A. Random point sampling A grid is drawn over a map of the study area/ Random number tables are used to obtain coordinates/grid references for the points. Sampling takes place as feasibly close to these points as possible.

17 B. Random line sampling Pairs of coordinates or grid references are obtained using random number tables, and marked on a map of the study area. These are joined to form lines to be sampled. C. Random area sampling Random number tables generate coordinates or grid references which are used to mark the bottom left (south west) corner of quadrats or grid squares to be sampled. Figure one: A random number grid showing methods of generating random numbers, lines and areas. Advantages and disadvantages of random sampling Advantages: Can be used with large sample populations Avoids bias Disadvantages: Can lead to poor representation of the overall parent population or area if large areas are not hit by the random numbers generated. This is made worse if the study area is very large. There may be practical constraints in terms of time available and access to certain parts of the study area. Systematic sampling: Samples are chosen in a systematic, or regular way. They are evenly/regularly distributed in a spatial context, for example every two metres along a transect line. They can be at equal/regular intervals in a temporal context, for example every half hour or at set times of the day.

18 They can be regularly numbered, for example every 10th house or person. Methodology A. Systematic point sampling A grid can be used and the points can be at the intersections of the grid lines (A), or in the middle of each grid square (B). Sampling is done at the nearest feasible place. Along a transect line, sampling points for vegetation/pebble data collection could be identified systematically, for example every two metres or every 10th pebble. B. Systematic line sampling The eastings or northings of the grid on a map can be used to identify transect lines (C and D). Alternatively, along a beach it could be decided that a transect up the beach will be conducted every 20 metres along the length of the beach. C. Systematic area sampling A pattern' of grid squares to be sampled can be identified using a map of the study area, for example every second/third grid square down or across the area (E) - the south west corner will then mark the corner of a quadrat. Patterns can be any shape or direction as long as they are regular (F). Figure two: Systemic sampling grid showing methods of generating systemic points, lines and areas. Advantages and disadvantages of systematic sampling Advantages: It is more straight-forward than random sampling. A grid doesn't necessarily have to be used, sampling just has to be at uniform intervals. A good coverage of the study area can be more easily achieved than using random sampling.

19 Disadvantages: It is more biased, as not all members or points have an equal chance of being selected. It may therefore lead to over or under representation of a particular pattern. Stratified sampling This method is used when the parent population or sampling frame is made up of sub-sets of known size. These sub-sets make up different proportions of the total, and therefore sampling should be stratified to ensure that results are proportional and representative of the whole. A. Stratified systematic sampling The population can be divided into known groups, and each group sampled using a systematic approach. The number sampled in each group should be in proportion to its known size in the parent population. For example: the make-up of different social groups in the population of a town can be obtained, and then the number of questionnaires carried out in different parts of the town can be stratified in line with this information. A systematic approach can still be used by asking every fifth person. B. Stratified random sampling A wide range of data and fieldwork situations can lend themselves to this approach - wherever there are two study areas being compared, for example two woodlands, river catchments, rock types or a population with sub-sets of known size, for example woodland with distinctly different habitats. Random point, line or area techniques can be used as long as the number of measurements taken is in proportion to the size of the whole. For example: if an area of woodland was the study site, there would likely be different types of habitat (sub-sets) within it. Random sampling may altogether miss' one or more of these. Stratified sampling would take into account the proportional area of each habitat type within the woodland and then each could be sampled accordingly; if 20 samples were to be taken in the woodland as a whole, and it was found that a shrubby clearing accounted for 10% of the total area, two samples would need to be taken within the clearing. The sample points could still be identified randomly (A) or systematically (B) within each separate area of woodland.

20 Figure three: A diagram highlighting the benefits of using stratified random sampling and stratified systemic sampling within certain fieldwork sites. Advantages and disadvantages of stratified sampling Advantages: It can be used with random or systematic sampling, and with point, line or area techniques. If the proportions of the sub-sets are known, it can generate results which are more representative of the whole population. It is very flexible and applicable to many geographical enquiries. Correlations and comparisons can be made between sub-sets. Disadvantages: The proportions of the sub-sets must be known and accurate if it is to work properly. It can be hard to stratify questionnaire data collection, accurate up to date population data may not be available and it may be hard to identify people's age or social background effectively.

21 The Study Sites The Isle of Sheppey Site 1 - Barton s Point

22 Site 2 The Leas/ Minster Cliffs