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GCSE Investigating rivers
Task question: How and why channel characteristics vary across Chrysochou River (Cyprus) with
distance downstream.
Format:
• Font: arial 12 - apart from headings (larger) and annotations (smaller)
• Line spacing: 1.5 (apart from annotations (smaller)
• Left margin: minimum 3 cm
• Headings and sub-headings: larger font and/or use of colour
• Number each Figure (map, photo, graph, table) and give it a title (What does it show?). Label
and annotate it.
• Number pages
Front page:
Candidate Name:
Candidate Number:
Centre Name: American Academy Larnaca, Cyprus
Centre Number: 91445
How and why channel characteristics vary across Chrysochou River (Cyprus) with distance
downstream.
Add a photo of the fieldtrip.
Page of contents
Sample from a student from a previous investigation
Introduction: (pages 3-16)
 Purpose of the investigation
 Location of the study area
 Geographical Background
 Aims and Hypotheses of the Investigation
 Aims and Hypotheses linked to geographical theory
 Sequence of investigation
Data collection: (pages 17-29)
 Sampling methods
 How primary data was collected
 How data was recorded
 Secondary data
 Other data collected
Analysis and Conclusions: (pages 30-45)
 Analysis
 Conclusions
Evaluation: (pages 46-48)
 The methods to collect data
 The methods of presenting data
 The whole study: its accuracy and the reliability of the results
 How the work could b improved if the investigation was repeated
References: (pages 49-50)
Page Number:
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14
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16
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24
28
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29
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44
Page Number:
47
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48
Page Number:
 Websites and books used
Appendix: (pages 51-52)
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Page Number:
 Data collected the day of the field trip
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Section 1: The purpose of the investigation – introduction (6 marks)
(a) Purpose of the investigation
The purpose of the investigation is to study how the channel characteristics of the Chrysochou River
change downstream and to examine the factors which affect these variations.
(b) Location of the study area
(i) Location of the study area in Cyprus
Write a sentence to locate your study area. Where is it in Cyprus?
Add that it is located between Goudhi and Evretou Dam.
Internet Search: Find a map of Cyprus. You must copy and paste the hyperlink on a separate document
called
‘References’.
(Add
thestudy
map to
theinsection.)
Figure
1 - Location
of the
area
Cyprus.
Figure 1: Location of the study area in Cyprus
(ii) Location of the three sites in the study area
Internet Search: Download a satellite image from Google Earth or a map which covers the area between
Evretou Dam and Goudhi (Refer to the map given by your teacher to find the location of the three sites. )
.
• The
name
of the river/tributaries
ADD:
Exact
longitude/latitude
of the three sites:
Site 1 34.969081,32.453769
• The
name of the settlements: Goudhi and Skoulli
Site
2 34.981397,32.451410
Site 3 34.992507,32.444869
• Evretou
You
may useDam
http://itouchmap.com/latlong.html to locate your sites on a satellite map of Cyprus.
Label the satellite image with:
• The three sites (use a symbol such as a pin)
• The name of the river/tributaries
• The name of the settlements: Goudhi, Skoulli and Polis
• Evretou Dam
Draw:
•
•
The river/tributaries
The grid references from the map of the area given by your teacher.
(c) The geographical background of the study area: characteristics which may affect the discharge
of the river. Use annotated photos.
Site 1: Stream of the first order (no tributary) Catchment area: 9 km²
Geology: Limestone cliffs, consisting of permeable limestone with lots of bedding planes, cracks and
joints, allowing water to infiltrate (pass through it). This affects the volume of water in the river
channel as water doesn’t run off directly to the stream after rain + no tributary = Small volume of
water
High roughness of the channel
- Large boulders in the channel/ Vegetation  increase friction reduced velocity
Site 2: Stream of the second order (a few tributaries) Catchment area: 77 km²
Geology: The banks of the river and the sides of the valley are made of alluvium, which is a material
deposited by rivers. This is coarse sediment, gravel and clay that are permeable, affecting the
volume of water in the river channel, which decreases rapidly as water infiltrates the surface and
goes to the aquifer underground.
Human activity
Impact of agriculture on the discharge of the river: people abstract water from the river for
irrigation, decreasing its discharge.
Roughness of the channel: Boulders and vegetation  friction affects velocity
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Site 3: Stream of the third order (many tributaries) Catchment area (km²): 84
Geology: River channel made of coarse sediment, gravel and clay, that are permeable, affecting the
volume of water in the river channel, which decreases rapidly as water infiltrates the surface and
goes to the aquifer underground.
Human activity
Impact of agriculture on the volume of water in the river channel: people abstract water from the
river for irrigation.
Before the bridge: Increased roughness due to vegetation (Eutrophication). The channel was
widened 6 years ago, increasing friction.
After the bridge: Smaller channel than before the bridge, not affected by human impact. Boulders in
the river channel. Vegetation on the banks Increase friction, increase roughness, decrease velocity
(d) Hypotheses:
We plan to investigate the channel characteristics of the river based on the Bradshaw model.
(i) Investigating how channel characteristics change downstream:
Bradshaw’s model suggests that theoretically there will be:
Add Figure to show the Bradshaw model . Draw your own or find a clear image in the Internet.
Figure The Bradshaw model
Describe the changes expected downstream.
(ii) Investigating the factors which affect the characteristics of the channel:
Link the hypotheses to the geographical theory. Why do you expect these characteristics to
increase/change with distance downstream?
1- Read the theory: Textbook pages 66 and 67. What are the reasons for the expected changes
from the source to the mouth of a river? Write them down using your own words. Need more
help? Read the notes below.
2- Geographical theory (my notes)
Discharge is the volume of water flowing in a river per second, measured in cumecs (m3/s). It
increases downstream as more water is added to the channel by tributaries and groundwater flow.
Furthermore, as velocity is also a component of discharge, the higher velocity downstream also
affects it.
Velocity is the speed of flow of water in the channel. It is expressed in metres per second. Velocity is
influenced by three main factors: gradient, channel roughness and efficiency. It increases
downstream even if gradient normally decreases downstream. Therefore, river velocity is
determined by the efficiency of the river in overcoming friction with the bed and banks. Why does a
river become more efficient in its lower course?
(i)Shape of the channel - the river is deeper, wider in its lower course due to vertical and lateral
erosion*. Relatively less water is in contact with the wetted perimeter, so friction from the bed and
the banks is reduced. Therefore, the velocity and the discharge increase downstream.
(ii)Channel roughness - pebbles, stones and boulders on the beds and banks of the upper course of a
river increase the roughness of the channel. The wetted perimeter is higher, increasing friction and
reducing the velocity of the river. Channel roughness is higher in the upper course than further
downstream. Therefore, velocity and discharge increase downstream.
(iii)Channel efficiency (Hydraulic radius). The effect of the bed on velocity is determined by how
much of the water comes into contact with it. This depends on the length of the wetted perimeter
and the cross-sectional area of the channel. The ratio between the cross-sectional area and the
wetted perimeter is termed the hydraulic radius. The higher the hydraulic radius, the more efficient
the channel shape as less water is in contact with the bed and banks. More of the water can move at
a higher velocity. As hydraulic radius increases downstream, the velocity and the discharge also
increase.
* Erosion depends on the river energy left after overcoming friction. The lower the friction, the more
the amount of energy left to erode. As friction decreases downstream, erosion increases and the
river channel becomes wider (lateral erosion) and deeper (vertical erosion)
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Previous hypotheses
Therefore we expect the following to occur from site 1 to site 3:
a- positive correlation between discharge and river width and depth
b- positive correlation between discharge and velocity
C- negative correlation between discharge and gradient
d- negative correlation between discharge and bed roughness
Changes:
Therefore we expect the following correlations to occur from site 1 to site 3:
a- positive correlation between discharge and river width and depth
b- positive correlation between discharge and velocity
c- positive correlation between discharge and hydraulic radius
To be able to support or refute these hypotheses I will:
For each site along the river:
 Measure the velocity of the river
 Measure the width of the river
 Measure the depth of the river
 Measure the wetted perimeter of the river
 Measure the gradient of the river
 Measure the roughness of the river
(e) Why is the location of the three sites appropriate?
 The three sites are located at different parts of the river’s course namely upper, middle and lower,
and therefore, show varying channel characteristics.
 Each of the three sites shows contrasting landscapes.
 The data collection can be done in one day.
SECTION 2- DATA COLLECTION (9 marks)
► This should include a detailed description of the methods used to collect the data.
► The methods used to collect the data must be explained. You must explain why you
collected the data in the way you did.
► The methods used to collect the data have to be justified and linked to the original
hypotheses.
This section must be written up independently
Short introduction:
The data collection took place on the (DATE OF THE FIELDTRIP). Data collection was organised for all
the class, but primary data was collected in small groups (?) of students.
In order to study the hypotheses, it was decided to use different sampling methods to collect
reliable data.
 Dates of the fieldtrip:
ADD Risk assessment
Risk assessment involves looking at the site, its surroundings, the weather and possible hazards. You
have to show that you understand the dangers, and that you know how to reduce the likelihood of
the risk becoming a real hazard. Finally, you need to show that you were continuously monitoring
the risks as the day progressed. You must consider more than one risk and link risks to action taken
to minimise them.
Data was taken at safe sections of the river under the supervision of three teachers.
 The chosen sites were easily accessible from main roads making them appropriate for safety
reasons.
 At each site the river’s flow was at a safe velocity and depth without any dangerous hazards.
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 ??????
A: Sampling methods.
Either draw a Figure or use annotated photos to show the sampling methods and justify their use.
(Explain why you used these methods). Give a definition of each sampling method (Use Internet)
B-Limitations of sampling methods
For instance, limitations of systematic sampling at site 1: boulders/vegetation etc…
No velocity is also a limitation.
Use annotated photos to present limitations. Describe them and explain how they limit data
collection. What have you done to overcome these limitations?
C- How primary data was collected
Add annotated Photo of equipment used.
For each data collected, use annotated photos to describe and justify each method of data collection
(link it to hypotheses). If you had any problem (linked to the use of equipment) mention it and the
solution given to overcome this problem.
Roughness was not measured but described. The following table will be used to give a coefficient of
roughness to each site.
Draw a cross-section of one site to show how you are going to use data on width, depth and wetted
perimeter.
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D- How data was recorded
Explain how data was recorded or add an annotated photo. Mention that tables with primary data
collected the day of the field trip will be added on appendix. You will add the page number of
appendix when you write your final coursework.
E- Other primary data collected
Justify these data
- information for geographical background
- photos to be included in writing up of the coursework
- sketches for geographical background
F-Secondary data
The data of each group was collated by our teachers to provide secondary data, as it is necessary for
the following reasons:
1) As we were divided into 11 groups, and each group surveyed 3 sites, this gives us data for
33 sites, which is a suitable number to use in statistical analysis.
2) This provides us with more reliable and accurate data.
3) The primary data of each group can be compared to the overall findings of the class and the
evaluation of our investigation is easier to be made.
Section C Analysis and conclusions (9 marks).
This section requires to extract information from the data collected, to provide analytical comments
and to reach conclusions based on the evidence obtained. The aim of this section is to answer the
task question: How and why channel characteristics change downstream.
Moreover, you will have to use a range of appropriate data presentation techniques. A number of
them must be sophisticated to reach to achieve high marks for data presentation (11 marks).
Click on this link for more about Geography Skills and Techniques for Analysis:
http://www.geographyiseasy.com/archives/317
The structure of section C is based on the hypotheses written in section A.
1- Analysis
(a) How do channel characteristics change downstream?
The first step to answer this question is to organise the data collected (primary and secondary data)
to see overall changes and changes between sites. The best way to do it is to create two tables, one
for primary and the other for secondary data.
Secondary data
Characteristics
Site 1
Change
Site 2
Change
Site 3
Width(m)
Average depth (m)
Wetted perimeter
(m)
Cross sectional area
(m²)
Channel gradient (º)
Hydraulic radius (m)
Average velocity
(m/s)
Gradient
Discharge (cumecs)
1.77
2.96
4.73
0.32
5.05
Overall
change
3.28
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Primary data
Characteristics
Site 1
Change
Site 2
Change
Site 3
Overall
change
Width(m)
Average depth (m)
Wetted perimeter
(m)
Cross sectional area
(m²)
Channel gradient (º)
Hydraulic radius (m)
Average velocity
(m/s)
Gradient
Discharge (cumecs)
These tables will be used to:
1- annotate graphs
2- Compare changes of channel characteristics downstream, i.e. Similarities, differences on overall
changes and rates of increase/decrease between sites. (primary and secondary data)
At this stage of section C, you must:
- draw graphs to show primary and secondary data by site for each characteristic;
- annotate each graph to describe changes.
- write a paragraph which compares changes.
(b) Why do channel characteristics change downstream?
1- Draw annotated scattergraphs to show correlations between channel characteristics, based on
hypotheses from section A:
a- positive correlation between discharge and river width and depth
b- positive correlation between discharge and velocity
c- positive correlation between discharge and hydraulic radius
2- Use coefficients to measure the strength of these correlations.
Present all correlations in a table to sum up your findings
Coefficients
HR/V
0.57236
Discharge and:
Width
Depth
CSA
(m)
(m)
WP (m) (m²)
HR (m) V (m/s)
0.71791 0.81451 0.81643 0.87726 0.77874
0.8735
3- Is there any other correlation?
(c) Draw together your findings from parts (a) and (b) and explain them.
The reasons will come from the geographical theory from the textbook and the geographical
background of each site.
(B)- Conclusions
Time to summarise your findings and answer the task question!
Step 1-Do your findings match the hypotheses on section A? Are there any anomalies? Have you
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found other correlations?
Step 2- Write the task question: how and why channel characteristics vary across Chrysochou River
with distance downstream…and answer it! Sum up your findings!
Sample from a student from a previous investigation
There is a positive correlation between discharge and river depth.
The correlation coefficient of correlation assesses the degree to which depth increases with
discharge. There is a strong positive correlation for secondary data with a correlation coefficient of
0.587203 with 1% of possible error (see figure 25, page 33)*. Actually, there is a high positive
correlation between them, according to the geographical theory too. This states that discharge
affects depth because, as it increases downstream since more tributaries are added to the main river
and its volume gets higher, it decreases roughness. This means less friction and, therefore, more
energy is left for vertical erosion, increasing its depth. However, there are some anomalies on the
graphs (see figure 23 and 24, page 32-33) that do not support the hypothesis. These anomalies
might have been caused by the characteristics of each site such as some water being abstracted
from the river for irrigation, lowering its level and depth.
The hypothesis that suggests an increase of depth as discharge increases downstream is correct.
* Use of cross-references
Section D: Evaluation
Comment on the strengths and weaknesses of different aspects of the study. Use cross-references
1- Discuss the strengths and weaknesses of the methods of data collection.
Sample from a student from a previous investigation
4.1 The methods to collect data
(i)Sampling Methods
Line Sampling: We used this to collect data along the cross-section, it was necessary for systematic
sampling. This method was used for measuring the width, the wetted perimeter, and the roughness
of the river (see section 2, page 9, figure 6). This sampling method was adequate and we did not
face any problems putting it in action.
Systematic Sampling: We used this form of sampling at places where we expected a variable to
change over distance, for instance, to measure depth and velocity. It is a form of sampling where we
take measurements at equal distance along the cross section (see section 2, page 9, figure 6).
Using the above sampling methods, we faced some limitations. For instance, where we had to make
a reading, according to line sampling, there were large angular boulders that prevented us from
taking the reading (see section 2, figures 7-9). This made our results less reliable so our methods of
collecting data are not fully adequate.
(ii) Equipment Used
The equipment we used was: a flowmeter to measure the velocity, a tape measure to measure
width, depth, velocity and wetted perimeter, a clinometer and ranging poles to measure the
gradient, and a meter ruler to measure the river depth (see section 2, page 12, figure 10). Every
equipment we used was good enough and provided us with accurate and reliable data, however, we
had a problem with the flowmeter (see figure 13, page 14) as it was inaccurate at low velocities with
result some measurements were zero recorded. This is why I believe we did not manage to find a
correlation for velocity and the data recorded by the flowmeter was not very accurate and reliable.
2- Discuss the strengths and weaknesses of the methods of data presentation.
Sample from a student from a previous investigation
4.2) Evaluating the methods of data presentation:
To clearly present our data, I used a variety of ways. The ways I used to present my data were aimed
to show clearly the data collected, the information and evidence I wanted to illustrate and also any
existing correlations or relationships between my data.
To provide evidence of the geographical background and the river channel characteristics I used
photographs. To provide additional information I annotated and labelled the photographs. By
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combining photographs, annotations and labels I clearly presented a lot of valuable information in a
figure and I successfully presented my data.
I also used different types of graphs such as line graphs and scatter graphs to present my data in an
analysable and comparable form. I was then able to analyse my data to find and exclude anomalies
to make my results more reliable. This type of presentation helped make my results more reliable.
I also used tables to present my data because it was easier to compare two variables and make
mathematical calculations. Also, it was easily to reach some conclusions that were previously
unnoticeable. Tables helped eliminate any human errors in mathematical calculations and made my
results even more reliable.
To accurately locate the sites and rivers in the study area I made use of GIS. This helps me to retrieve
more accurate results as satellite images are very accurate and sometimes more accurate than the
map. Also this makes my results more reliable since it avoids any human error by the cartographer
on the map.
I conclude that the methods of data presentation I used made my results more valid and reliable
because they helped me find patterns and exclude anomalies.
Missing: cross-references
3- The whole study; its accuracy and reliability of the results
Sample from a student from a previous investigation
4.3) Evaluating the whole investigation:
My investigation included a variety of strategies, collection methods, presentation methods and
analysing methods which made my results more valid and reliable. However, due to some limitations
and problems we had collecting the data, my data can be questioned and therefore the accuracy and
reliability of my result drop. My data are accurate enough to get results and come to a conclusion.
Considering the support of my findings with geographical theory, I conclude that my results are
reliable and valid at a high degree.
4 - Making specific reference to your results, suggest how your enquiry could be improved.
Sample from a student from a previous investigation
How the work could be improved if the investigation was repeated
aEquipment:
The data collected from my investigation could be improved in terms of reliability and accuracy if we
used a better flow meter for taking measurements of the velocity. A flow meter that it could
measure even the smallest velocity very accurately as the river’s velocity is not very high.
bSampling methods:
I could use the sampling methods for collecting data from more sites and at more regular intervals.
In this way I could compare my results from all the sites and improve my investigation. I could also
see if there was any pattern in my results or if our hypothesis were completely wrong or correct.
Also we could be surer that our results were correct as well as reliable and accurate.
cSeason:
My investigation could also be improved if we collected data during a season with very high rainfall.
If the river had more water the discharge of the river would be higher, as the volume of water would
be higher as well as velocity and friction would be smaller. In this way we would be able to collect
more accurate and reliable results.
Next page:
References for investigation
Last page: Write ‘Appendix’