Rivers field work

Question 1

What are the advantages and disadvantages of quantitive data?

Answer 1

Advantages:

• research can be replicated easily.
• data can be managed more easily.
• avoided personal opinions and biased
• not taking into a account person judgement

Disadvantages:

• limited results
• provides numerical descriptions rather than detailed narrative.
• Takes longer to collect this type of data.

Question 2

Advantages and disadvantages of qualities data are?

Answer 2

Advantages:

• allows for a broader more in-depth study.
• data quicker and easier to collect.

Disadvantages:

• can not replicate easily
• could be subject to personal biased open to personal opinion
• harder to analyse data that is not numerical.

Question 3

For your chosen location explain 2 that you collected quantitive field work data (4 marks):

Answer 3

The first way we collected quantitive data was by using a flow meter to measure velocity. Flow meter should be placed just below water line. Attach an impeller to the rod and then put in water facing upstream and start stop watch soon as submerged under water. When impeller reaches end of rod stop stop watch and use table provided to convert time into m/s.
The second way is measuring the width of the river. One student should hold the tape measure at 0 parallel to the water line while another student should stretch it across river holding it tight. Read measurement from other side and cross check with another student.

Question 4

Explain one way in which you attempted to make your data reliable. (2 marks):

Answer 4

One way in which we tried to make our results reliable was that for example when taking data for width to ensure accurate data we took measurements several times to work out an average and of a larger data set. This was to make sure anomalies were not counted.

Question 5

Explain one advantage of using a line graph to show long profile of a river. (2 marks)

Answer 5

One advantage is that it shows visual change over the course of multiple sites. This makes it easier to interpret data. This will make reaching a conclusion or comparison more accurate and meaningful.

Question 6

Explain one technique that you used to present your river data. (2 marks)

Answer 6

One technique I used was to put my data into a scatter graph. This meant my data could be viewed clearly and it also highlighted any anomalies. It also meant I could see changes over different sites. This shows me weather it is a positive or negative correlation.

Question 7

Research and identify two ways in which you can use GIS to present field work data along a river (2 marks):

Answer 7

GIS could be used to present fieldwork data through looking at an Environment Agency flood risk map. This highlights areas at risk from flooding. I could then plot these onto an OS map of the area. It could be used to create layered maps to show which parts of the river have fastest velocity and are more likely to flood.

Question 8

What is the importance of an evaluation?

Answer 8

• to ensure quality of results are improved next time.
• to increase validly of results of your investigation.
• important to accept no study is perfect.
• to produce more reliable results next time.

Question 9

Explain one way about your own primary data, which could have affected your results. (2 marks)

Answer 9

One factor that affected my results was that on the day vegetations kept getting caught on the flow meter. This therefore slowed the flow meter down and led to inaccurate results.

Question 10

Why did we choose the aims we did?

Answer 10

• Easily accessible for school trips to visit different results.
• analysed middle course as it was easy to get there.
• it’s not too wide or too deep.
• wanted to see how characteristics change down stream. Middle course offer features -meanders.
• small drainage basin means easy to analyse.
• Sparsely populated

Question 11

Affects of primary and secondary data:

Answer 11

• accuracy errors.
  Analyse how we could have done it well or wrong.
• assess potential faults and methods to do more accurately.

Question 12

Data presentation methods:

Answer 12

• human intervention

- scatter graphs

Question 13

For the river along which you carried out field work, explain two reasons why particular aims or questions were developed? (4 marks)

Answer 13

I have previously learned that a river flows downstream and gets wider and deeper due to lateral erosion. It also has an increase in tributes that flow into it. The drainage basin land becomes flatter the more you travel downstream as on the maps we saw before undertaking the field trip. The Bradshaw model also tells me this and these factors combined with and increase in settlements further downstream will increase flood risk.

Question 14

What is our enquiry question, aim and hypothesis?

Answer 14

EQ: how do different drainage basin and river characteristics influence flood risk for people and property along the river Tillingboune?

Aim: investigate how and why drainage basin and river characteristics influence flood risk for people and property along a river in the UK?

Hypothesis: the drainage basin and channel characteristics will change as we go downstream and the flood risk will increase.

Question 15

Where is the river Tillingbourne?

Answer 15

It runs along the south side of the North Downs and joins the river Wey at Guildford. The source is located in the Tilling springs to the North of Leith Hills. Grid reference TQ143437 and is 18 km long.

It’s geology consists of chalks clays and sands.

Question 16

In brief terms explain what you can analyse form the Bradshaw model.

Answer 16

Discharge: increase downstream due to more tributes feeding in meaning larger volume.

Channel width/depth: increases downstream due to increase in lateral erosion as discharge increases and helicoidal flow sent laterally.

Average velocity: increases as discharge increases because of more tributes. More water means speed increases and this can cause a change in direction and that’s why meander occurs in middle course.

Load quantity: increases because tributes feed into the over and they carry transport and deposit their load quantity into the river they’ve joined.

Load particle size: decrease downstream particles cause abrasion and run against each other causing fragments to erode so it becomes smoother.

Channel bed roughness: decreases because increase in discharge and velocity speed up erosional processes along bed making it smoother.

Gradient: decreases sources are often in mountains high above sea level. Water makes it way downwards towards sea. Further downstream land is flatter meaning gentler gradient.

Question 17

Why are we using secondary data?

Answer 17

We only visited 2 sites along the river Tillingbourne and therefore need more information. I used River Tillingbourne Fielwork site information to get info about 8 other sites. Also due to human errors and extreme weather conditions some of my results may be inaccurate or incomplete and therefore need to use secondary data form other groups or pr ious studies.

Question 18

What does the width of the river show form the scatter graph?

Answer 18

Positive correlation because width increases from distance form the source increases. This shows that Bradshaw model is correct.
Mean average : 3.265 meters
Median: 2.75 meters
Range: 6.57 meters
There are no anomalies in the data set because width increases downstream due to lateral erosion.
This links back to hypothesis as it fully supports it.

Question 19

What the depth of the river show from the scatter graph?

Answer 19

Positive correlation because depth increases due to lateral and vertical erosion downstream. However my data set suggests otherwise.
Mean average: 0.156 meters
Median: 0.126 meters
Range: 1.963 meters
There is one anomaly in my data which is 0.21 meters at Cross Ways Farm 1. This could be due tonight accurate measurements we took on the day.
Although the results are varied due to anomalies through the overall course form start to finish the depth does increase due to lateral erosion.
This links back to hypothesis but shows it may not always be correct.

Question 20

What does the velocity from the scatter graph show?

Answer 20

Positive correlation as increase in discharge leads to an increase in velocity further downstream. This tellls is Bradshaw model is correct.
Mean average: 1.03 m/s
Median: 0.294 m/s
Range: 7.407
There was one anomaly who was at site 8 Gomshall 2- 7.5 m/s perhaps due to heavy rainfall that day which increased it at that site as it was further down the river do more urbanised so more surface run off and less preamble surfaces.
This overall states my hypothesis is correct.

Question 21

Give examples of risks and precautions:

Answer 21

Drowning - wear sensible food ware and clothing and steep careful in and out of river.

Uneven or slippery ground - ensure students walk carefully is sensible shoes to prevent falling.

Farm animals - ensure students are aware of animals are and are able to remain calm and ignore them while carrying out field work. Stay away from them as much as possible and and move away slowly if in danger.

Question 22

How I collected data for width and why:

Answer 22

1. One person had the tape measure at zero against water line at one side of bank. Another student stretched it across and held it tight at other side of bank parallel to river at water line.
2. Tape measure should be held tight and perpendicular at all times. Another student should then take measurement of width and someone else should check this is right to avoid mistakes.

(I collected this data in order to prove my hypothesis was correct and that channel width increases downstream. It it correct)

Question 23

How I collected data for depth and why:

Answer 23

1. Divide the width by 11 ( you will be taking 11 measurements or depth) this will be the number you increase by when you move to your next point when measuring.
2. 2 people keep tape measure steady and tight while two other students place meter ruler at 0 pm tape measure and start measuring fro outside of bend.
3. While one person keeps the meter ruler steady and side on to river while another bends down to take measurement.
4. Move on to point 2 and repeat this method 9 more times after this (11 times in total) until you reach other side of bank. The final measurement should be that of the width. (Final measurement on tape measure.)

( I collected this in order to prove the further down a river you go the deeper it gets. This shows my hypothesis is correct.)

Question 24

How did I collected velocity and why:

Answer 24

1. attach impeller and rod to flow meter and insure impeller is at end of rod.
2. Put rod vertically in the water. It should be submerged underwater. Impeller should be faced upstream and not one should be in river to prevent interference of results.
3. As soon as flowmeter is submerged under water a person should start the stop watch.
4. When impeller reaches the other end of rod (beginning) the person should stop the stop watch. The time on the stop watch should be converted on to m/s using conversion table provided.
5. Repeat this so that velocity measurements are taken in the middle and other side of river. Ensure no vegetation gets caught up in flowmeter as this will cause inaccurate results and may damage equipment.