AS Level coursework (Christos Theodoulou)
Hypothesis:
The size (volume) of beach material will decrease and the sphericity will increase (become
rounder) as you move along a transect from the cliff line to the water.
Aim:
State the aim of your investigation and describe one method of data collection
associated with the aim. (6 marks)
State one hypothesis or research question or issue for evaluation that you
have investigated in 2(a)(i). Describe one method of primary data collection
used in this investigation. (5 marks)
You have experienced geography fieldwork as part of the course. Use this experience
to answer the following questions.
State the aim of the fieldwork investigation. (2 marks)
To investigate the changing pattern of sediments across a shingle beach at Bexhill in Sussex.
Purpose of investigation:
Describe the geographical theory, concept or idea that formed the basis of your
fieldwork investigation (3 marks)
Describe the purpose of your fieldwork enquiry. (5 marks)
Explain the geographical concept, process or theory that underpinned your fieldwork
enquiry. (4 marks)
We investigated the changing pattern of sediments across a shingle beach at Bexhill in Sussex. We
also wanted to know if it displayed the theoretical characteristics as outlined in the theory such as
Power’s Scale of Roundness in regard to sphericity and the expected change in size caused by
grading as a result of swash and backwash.
Theoretically as the distance from the cliff increases we would expect the volume (length x width x
depth), to decrease. This is because of the impact of the erosive process of attrition caused by the
swash and backwash of the waves which reduces the volume of the material. Additionally we
would expect sphericity to change from a more angular type to a more rounded type as recognised
from Power’s Scale of Roundness. This is because the process of attrition mentioned earlier means
that the constant collision of material creates a more rounded shape.
Describe the location of your fieldwork and outline why this was a suitable
site for your investigation. (4 marks)
This was a suitable site for the investigation as it was within 2 hours drive from our school which
meant that the investigation could be carried out in 1 day. Additionally using GIS such as google
earth meant that we could establish the presence of a shingle beach which was necessary for our
investigation. A risk assessment had been undertaken before our visit, and one aspect of the site
that meant it was safe was the very gentle sloping beach which meant that student working at the
water’s edge were not in danger of falling into deep water.
Sketch map – Location:
In the box provided below, draw an annotated sketch map of the location of your study
area to show its basic characteristics.(5 marks)
Methods:
Outline and justify one method of data collection that you used in your enquiry. (6 marks)
Describe one method that you used for the collection of primary or secondary data. (6 marks)
Command
words:
Outline
Describe
Command
words:
Justify
Explain
We sampled sediments along a transect across a beach. Starting at a cliff line, we took our
compass bearing to ensure we stayed in a straight, consistent line. We then laid out a tape
measure and collected beach material every five metres. At each interval one member of our
group closed their eyes and collected 20 pieces of beach material randomly. We used the Powers
Index of Roundness to judge the angularity of the sediments and recorded the data on a table. We
then used a calliper to measure the length, width and depth of each piece of material and
calculated the volume in cm³ (length x width x depth) and recorded the results on a table. Once
we had worked our way to the water, for each point we worked out the mean volume by adding
the ten volumes together and dividing the answer by 20. We repeated this for the sphericity in a
similar fashion.
We used this technique because it is a straight forward technique, which doesn’t require any
specialist equipment other than a pair of callipers. The random sample technique greatly reduced
any possibility of the data being biased. By collecting 20 pebbles we also ensured that the
influence of any anomalies would be reduced. This is also the case for calculating the average
volume. We assigned a number value to each part of the Powers scale of roundness enabling us to
calculate a mean sphericity value in order to be able to present this data in a scatter graph or
apply a Spearman’s test to it.
Method – Evaluation:
Discuss the strengths and weaknesses of the method of data collection in 2(a)(i). (6 marks)
Discuss the limitations of your chosen method in 2(a)(ii). (6 marks)
Evaluate one method of primary data collection that you used in your enquiry (6 marks)
The strengths of the chosen method are that it made us able to carry out transects in four
separate locations allowing comparison between them. This shows us how sediment distribution
varies across a wide area of a beach. We all used a random sampling technique to eliminate bias in
our sample and ensured that the same technique was used each time to provide a strong,
consistent basis to our data. The use of callipers allowed us to accurately calculate the volume of
the pebbles as opposed to using a less accurate ruler. A compass was used to ensure that the
transect was consistently at 90° from the cliff to the water.
The weaknesses included the relatively small sample size of 20 which may have been affected by
anomalous data. This could be improved by taking a larger sample size which would allow for a
more comprehensive understanding and a more reliable data set less influenced by any
anomalies. The sphericity classification might be considered to be weak as it is a subjective form of
classification, leading to disagreements between group members. This could have been overcome
by one person only classifying sphericity which would create a consistent classification.
Data collection - Primary and secondary data:
Distinguish between primary and secondary sources of data used in your fieldwork
Enquiry (3 marks)
A primary source is a set of data which is original to the investigation. It must be collected by the
person undertaking the investigation at the time it took place. Lastly it must not be drawn from a
previously published source. We used a primary source of data in this investigation when we
collected the measurement data on pebble volume along the transect.
A secondary source of data is one which is not original to the investigation and has been
previously published. An example could be using similar data collect previously to compare with
the findings of this investigation.
Outline how you obtained and why you used secondary data in your enquiry. (5 marks)
Describe and explain one method of secondary data used in your enquiry (5 marks)
We used an OS map of the area we were investigating, we downloaded this from
www.streetmap.com and used it in preparation for our field work. From this we were able to see
the location we were going to in relation to our school. We used it so we could identify the study
area and possible the sites we would use, for example the variety in the sites some with coastal
defences and some without. Another source of secondary data was the use of GIS such as google
earth which we used to identify the presence of a shingle beach which was necessary for our
investigation.
Data collection - qualitative and quantitative data:
With reference to your fieldwork investigation, distinguish between qualitative and
quantitative data.(4 marks)
Qualitative data involves the collection of opinions, perspectives, thoughts and feelings. It is
therefore more subjective in nature. Examples of qualitative data include open-ended
questionnaire responses or conversation analysis. These were not used in this particular
investigation however an investigation on coastal management techniques may have provided an
opportunity to use them in regard to people’s opinions of how they fit in with the environment.
Quantitative data is numerical in form. Therefore it is more objective in nature. In this
investigation examples that we used included measuring the length, depth and width of the
pebbles taken in the random sample along the transect.
Sketch diagram – Data presentation method:
With the aid of a sketch diagram, describe one technique that you used to present
data in your enquiry. (6 marks)
We used proportional
circles to show how the
volume of the sample
changed along the
transect. As the
circumference of the
circle changes it indicates
a higher average volume
at that same point. We
calculated the volume
and then worked out the
average, we then got the
square root of the
volume and then divided
it by pi. For the area of
the circle we used the
volume of the pebble
measured in cm3. This
gave us a proportional
radius which we drew
with a compass. This was
then overlaid on a map
of he transect.
Data presentation:
Describe one method used to present your data. (5 marks)
Outline and justify the use of one or more techniques used to analyse your results. (5 marks)
Outline one technique that you used to present results from your data collection. (4 marks)
With reference to one technique you chose to present data in your enquiry, justify the
choice of this technique (6 marks)
Command
words:
Outline
Describe
Command
words:
Strengths
Justify
Command
words:
Strengths
and
weakness
Evaluate
We used proportional divided circles to represent our beach study data. We first calculated the
estimated volume (length x breadth x depth) of each piece of beach material and then took an
average of the 20 sediments. This gave us an average volume for each 5 metre interval. We then
used a simple formula where radius is equal to the s
π (pi). For
the area of the circle we used the volume of the pebble measured in cm3. This gave us a
proportional radius which, using a compass then gave us a proportional circle for each of the
transects. We then used an overlay to display this data on a sketch map of the area.
This form of data presentation was useful because we could place the circles spatially on the map
which made this effective and clear when we were looking for trends during our analysis. As
proportional circles are a visual form of data presentation it made them very easy to compare, and
as they were overlaid on a map it put the information we gathered into context. This allowed us to
put a great deal of information in a small space.
Some of the weaknesses of proportional circles was that when the sizes of the circles were similar
it was hard to distinguish between them and this could have been improved by using a larger
scale when calculating the radius. Another issue was that when we overlaid the circles on the
map it made it difficult at time because they covered up the map. This could have been improved
by locating the circles around the map and show where they were collected from using arrows.
Risk assessment:
How did you respond to risks associated with undertaking your primary data
collection? (4 marks)
I/we identified potential risks before even visiting the site by researching other studies. We also
used GIS to evaluate the nature and risks of the environment. Additionally we investigated the
tide information in order to plan to work at low tide which is the safest time to do so. At the site, I
wore sturdy footwear in order to avoid slipping. We only conducted primary data collection in
good light for the same reason. We worked in pairs, just in case one of us did get injured. This
would make it easier to raise the alarm and call for help. We took a mobile telephone and made
sure to inform people of our whereabouts just in case we did get lost. We agreed to work
within earshot of each other in case either of us got into difficulties.
Data Analysis:
Command
words:
Strengths
Justify
Describe
Describe advantages of a technique that you used to analyse your data. (5 marks)
Justify your choice for using a technique you used to analyse your data. (5 marks)
I used a scatter graph with a line of best fit because is is useful in identifying any patterns or trends
in the relationship between the two variables. Scatter graphs also allow you to spot any anomalies
and because you can add a line of best fit you can easily identify the correlation of your data.
Spearman’s Coefficient is a good way to assess the extent to which two variables are correlated. It
provides a numerical value to summarise the relationship between two sets of data, so it is
statistically reliable. It is useful for testing hypotheses and can suggest relationships which are
worthy of further study but is also useful to assess the likelihood that a relationship occurred by
chance.
Command
words:
Strengths
and
weakness
Evaluate
Discuss the strengths and weaknesses of a technique that you used to analyse your data. (5
marks)
Evaluate a technique that you used to analyse your data. (5 marks)
Some of the disadvantages of using scatter graphs is that the line of best fit is subjective and the
relationship can only really be assessed using a statistical test like the spearman’s rank, but one of
the problems with the spearman’s rank is that the calculation becomes more complicated and
therefore more open to error if you have more than 30 sets of paired data, so the would be
implications if we decided to increase the size of the data set.
Conclusion:
How far did your fieldwork conclusions match the geographical theory, concept or
idea on which your investigation was based? (8 marks)
Our theory suggested that the largest beach material would be found at the back of the beach
(nearest the cliff) this is due to the sorting action of waves on a beach.
However our data was inconclusive in relation to the expected outcome. We found that average
particle size at the back of the beach was 12cm³. For some transects the data did indeed show a
decline in volume with distance from the back of the beach in line with the theory, but for others
the findings where inconsistent. The three transects (A, B, C), for example showed an increase in
particle size of 11cm3 at a distance of 15 metres from the back of the storm beach. If this were just
an isolated case, we might explain this as faulty data collection, but several other groups reported
similar trends. We also applied a Spearman’s Rank Correlation Co-efficient to analyse the strength
of the relationship mathematically. It showed that for the three inconsistent data sets to this
highlights the need for further research into the phenomena. We calculated the Spearman’s value
and found that they ranged between – 0.34 to – 0.57. This shows a weak relationship at best and
in terms of the lowest value almost that the null hypothesis was the case.
In terms of how this relates to theory, it is clear that there was little in the way of a relationship.
This would indicate that pebble volume does not uniformly decrease as the water’s edge
approaches as the theory would state. Grading by the waves does appear sporadically but not
consistently, as is shown in the various data sets. Based on our findings we can say that our
hypothesis has not been proved on the day of our investigation. It is clear that our findings do not
support the theory of beach material being graded by the waves through the action of backwash.
We would need to investigate further the reasons for this such as the potential impact of
interventions such as beach replenishment or beach material being moved by humans to alter and
steepen the profile in order to offer greater protection from erosion.
Evaluation
Drawing upon your findings, explain how your enquiry improved your
understanding of the topic. (5 marks)
Evaluate your investigation. In your answer, you should:
• comment on the strengths and weaknesses of different aspects of the study
• suggest improvements.
Explain how your fieldwork enquiry could have been improved. (6 marks)
Making specific reference to your results, suggest how your enquiry could be
improved.
The investigation did not manage to meet the original aim as we intended it to. There
were some strengths and some weaknesses and also room for improvement. Firstly I
expected the volume to decrease towards the water and our method was designed to be
able to investigate this however only three sites were visited limiting the scope for valid
conclusions to be drawn as only a relatively small sample was collected at each
measurement point. It may have been better to have taken a larger sample in order to
compensate for the impact of anomalous data. Additionally I took no account of where
the investigation took place. This may have been significant as the presence of coastal
protection or the provision of beach nourishment is well known to influence the grading
of material. I might have investigated by means of GIS such as Google earth whether these
were indeed present and also used a site where such interventions were not present to
either draw a comparison or indeed only use a site where there was little human activity.
The proportional circles was used to show the average volume of material along the transect. This
is a simple and accurate method of presenting this data as it is visual especially when overlaid on a
map showing the transect along the beach. However it can be difficult to construct these with
total accuracy as the scale is difficult to reflect in terms of the actual size of the pebbles for
example it was very difficult to show the size of the smallest material as a circle due to the scale
required to show all samples. I could have improved this by greatly enlarging the scale in order to
be able to represent the smallest material. This was clearly a serious limitation of the technique.