1. Data Presentation

2. What do the examiners say?

3. Hypotheses
1. Channel size or Cross Sectional area will increase with
distance downstream.
2. Channel efficiency will increase with distance from the
source.
3. Channel gradient will decrease with distance
downstream.

4. Essential Graphs
1. Channel cross sections of your own groups 4 sites.
2. Graph to show downstream change in Cross Sectional
Area (all 12 sites)
3. Graph to show downstream change in channel
efficiency (all 12 sites)
4. Graph to show downstream changes in channel
gradient (all 12 sites)
5. Pie chart to show downstream Average Powers Score at
12 sites. Powers data could also be shown as pie charts
for your own groups results (4 sites)

5. Are there photographs that will
support your data presentation?
From your photos find 10 images that you could
use as part of your data presentation

6. Cross Sectional Areas - Drawings
 You will need to draw a channel cross section graph for
each of your own groups 4 sites.
 These should be presented on graph paper and should be
to scale.

7. Cross Sections drawn to Scale

8. Deciding on Scale
 Width - (x axis) 1 metre = 2 squares on graph paper or




….cm
so a 3 metre river will have a width of six squares on the
graph.
Depth - (y axis) 1 metre = 10 squares or …..cm
so a depth of 70 cm will be 7 squares or ...cm on the
graph.
depth intervals- divide width by 11.

9. Fig 3.3 River Channel Cross section - Site1 - Upper Course.
Annotated
site photo
.010
m/s
Channel
Efficiency
0.22
m/s
0.01
m/s

10. Student Examples of Sophisticated Channel Cross Section –
Upper Cousre

11. Student Examples of Sophisticated Channel Cross Section –
Middle Cousre

12. Making your cross sections more sophisticated.
• Adding text to describe the shape of the channel.
• Calculating and commenting on channel efficiency.
•
•
of the channel.
Adding velocity data across the channel.
Plotting bedload on the bottom of the channel by
using proportional circles to show powers score for
each 10 pieces of bedload.

13. Cross Sectional Area - Trend
14.00
12.00
10.00
8.00
6.00
4.00
2.00
0.00
1
2
3
4
5
6
7
8
9
10
11
12

14. Cross Sectional Area - Trend
Cross Sectional Area of River Channel Downstream
14.00
LEGEND
12.00
Cross Sectional Area (m²)
Upper Course
10.00
Middle Course
8.00
Lower Course
6.00
4.00
2.00
Fig: 3.1
0.00
1
2
3
4
5
6
7
Sites
8
9
10
11
12

15. Now it’s your turn!
Draw a bar chart to show downstream
change in channel efficiency over the 12
sites.

16. Sophisticated Graphs

18. Bedload

19. Comparing Data
Average Channel Velocity against Channel Gradient downstream
25
0.30
0.25
20
15
0.15
10
0.10
5
0.05
0
0.00
1
2
3
4
5
6
7
8
9
10
11
12
Sites
Channel Gradient
Average Velocity
Linear (Channel Gradient)
Linear (Average Velocity )
Velocity m/s
Gradient (°)
0.20

20. Other graphs may be applicable
A scattergraph could be used if you do a
spearman rank coefficient of correlation to show
downstream site and CSA.