3.3.2 Section B: Physical Fieldwork

Question 1

Hypotheses for physical fieldwork enquiry:

Answer 1

How effective are the coastal management strategies in Newton beach?

Hypotheses:

1. There will be more sediment on the west side of the groynes than the east
2. Sediment size will be larger / more angular on the west side
3. Coastal defences at Newton Beach will have an impact on coastal processes

Question 2

Why is Newton Beach a suitable location for our physical fieldwork enquiry?

Answer 2

• The location of Porthcawl and prevailing wind means that waves have a very long fetch across the Atlantic ocean and therefore build up a strong force by the time they reach the coastline
  
  • SW prevailing wind
  • long fetch across Atlantic 7,000km
  • longshore drift more visible
• Discordant coastline will affect the rate of erosion in different areas e.g. Porthcawl and Trecco has younger limestone whereas Newton has mudstone - geology
• High value land being protected within the area e.g Trecco Bay Caravan park
• Wide range of coastal management strategies are being utilised within the area
  
  • lots of flood defences e.g. rock armour (rip-rap), sea wall, groynes
  • can measure how effective the coastal defences are

Question 3

Risks when collecting data for physical enquiry at Newton Beach:

Answer 3

• Slips, trips & falls
• Weather
• Tides
• Water

Question 4

Mitigations for risks when collecting data for physical enquiry at Newton Beach:

Answer 4

• heat stroke - use sunscreen and wear a hat
  
  • means that I was able to prevent getting sunburnt or sunstroke
• tripping over - wear sensible shoes
• getting lost - take a map and know where the agreed meeting location is
• drowning - stay 5m away from the water’s edge
  
  • means that the waves are unable to sweep me into the sea.

Question 5

Data collection method and equipment for “There will be more sediment on the west side of the groynes than the east”

Answer 5

• Primary - Beach profile
• Clinometer
• Ranging poles
• Tape measure

Question 6

Type of sampling used for “There will be more sediment on the west side of the groynes than the east”:

Answer 6

stratified

Question 7

Justification for the date collection method and sampling used for “There will be more sediment on the west side of the groynes than the east”:

Answer 7

• This shows helps us to investigate the shape of the beach by looking at how much gradient change there is as well as the width of the beach
  
  • This helps us to answer our hypothesis as we can see where more sediment is and if longshore drift has been impacted by the groynes
• Sampling = We are able to ensure that the sample reflects what we are aiming to investigate as there are a number of different coastal management strategies in the area

Question 8

Data collection method and equipment for “Sediment size will be larger / more angular on the west side”:

Answer 8

• Primary - Measuring sediment roundness using Powers Index of roundness scale
• Sediment size - callipers

Question 9

Type of sampling used for “Sediment size will be larger / more angular on the west side”:

Answer 9

Stratified for sea defences then random data collection for sediment using random number generator

Question 10

Justification for the date collection method and sampling used for “Sediment size will be larger / more angular on the west side”:

Answer 10

• This helps us to examine the sorting of beach material across the width of the beach which links to the process of longshore drift and the amount of erosion that is occurring in different areas depending on the type of coastal management
• Sampling = We are able to ensure that the sample reflects what we are aiming to investigate and then very item has an equal chance of being sampled

Question 11

Data collection method and equipment for “Coastal defences at Newton Beach will have an impact on coastal processes”:

Answer 11

• Primary – Fieldsketch
• Clipboard
• Paper & pencil

Question 12

Type of sampling used for “Coastal defences at Newton Beach will have an impact on coastal processes”:

Answer 12

stratified

Question 13

Justification for the date collection method and sampling used for “Coastal defences at Newton Beach will have an impact on coastal processes”:

Answer 13

• Field sketches are a useful form of qualitative data
  
  • They can help us to remember the places that have visited
  • By drawing a fieldsketch we were able to add annotations to show the sand dunes that had been stabilised using pins aswell as the large breakwater
  • We could also show the direction of LSD and wave refraction that would be occurring in the area to help us to answer our hypothesis
• Sampling = We are able to ensure that the sample reflects what we are aiming to investigate.

Question 14

Data for “There will be more sediment on the west side of the groynes than the east”:

Answer 14

Question 15

What is the general trend of these results showing the size of pebble of the east and west end of Newton Beach and what evidence is there to support this?

Answer 15

• The overall trend is a strong positive correlation between distance from the shore and height, as you move away from the shore the height of the sediment increases
• There is also evidence to suggest that there is more sediment on the west side of the groynes compared to the east due to the height of the line graph and the cross sectional area
• For example, the height of the sediment on the west side of the groyne goes above 2.5m whereas the east side does not go above 2m
• Additionally, the CSA of the west side is 23.52 m² compared to the east which is 20.48 m²

Question 16

Are the results for the hypothesis “There will be more sediment on the west side of the groynes than the east” showing what you expected?

Answer 16

• This is showing what we expected as our hypothesis was that there would be more sediment on the west side of the groyne than the east
• This is because the direction of the prevailing wind is from the south west and therefore impacting the direction of LSD
• As the sediment is blown onto the beach in this direction the groyne will stop some of the sediment from being transported down the beach and therefore increase the amount of sediment on the west side

Question 17

Looking at the other results is there any other evidence that supports these trends for the hypothesis “There will be more sediment on the west side of the groynes than the east”?

Answer 17

N/A

Question 18

How does the data for the hypothesis “There will be more sediment on the west side of the groynes than the east” help us answer the question “How effective are the coastal management strategies at Newton beach?”?

Answer 18

The groynes appear to be effective as they are trapping sediment along the beach and dissipating the wave energy to protect the area behind it

Question 19

Data for “Sediment size will be larger on the west side”:

Answer 19

Question 20

What is the general trend of these results for the hypothesis “Sediment size will be larger on the west side” and what evidence do you have to support this?

Answer 20

• The general trend is that there is a larger spread of pebble size on the west side of Newton Beach compared to the east
• There is also a difference in the median sediment size with the west having a larger median
• For example, the IQR is 27 on the east and 70 on the west
• Additionally, the median is 77 on the west compared to 58 on the east

Question 21

Is the data for the hypothesis “Sediment size will be larger on the west side” showing what we expected?

Answer 21

• This is showing what we expected to happen as our hypothesis was that sediment size would be bigger on the west compared to the east
• Pebbles will be larger on the west side as the large fetch brings powerful waves which are able to carry larger rocks
• These will be deposited when they reach the groyne due to the movement of LSD and losing energy

Question 22

Looking at your other results is there any other evidence that supports these findings for the hypothesis “Sediment size will be larger on the west side”?

Answer 22

yes, as the west had a larger beach profile than the east as well

Question 23

How does the data for the hypothesis “Sediment size will be larger on the west side” help us answer the question “How effective are the coastal management strategies at Newton beach?”?

Answer 23

• This is showing what we expected to happen as our hypothesis was that sediment size would be bigger on the west compared to the east
• Pebbles will be larger on the west side as the large fetch brings powerful waves which are able to carry larger rocks
• These will be deposited when they reach the groyne due to the movement of LSD and losing energy
• Shows the groynes are effective at reducing longshore drift

Question 24

Data for “Sediment size will be more angular on the west side”:

Answer 24

Question 25

Describe the trend in date for the hypothesis “Sediment size will be more angular on the west side” and provide evidence to support this trend:

Answer 25

• West newton beach has more variation in the shape of the pebbles ranging from well rounded to very angular with the majority of pebbles being well rounded (30%)
• East newton beach has much more rounded pebble shape overall however over 50% of the pebbles were either sub rounded or sub angular

Question 26

Is the data for the hypothesis “Sediment size will be more angular on the west side” showing what you expected?

Answer 26

yes, as on the west side, the rocks are trapped by the groyne o cannot be eroded to become smoother whereas on the east side due to water being deeper, more attrition takes place as more sediment is carried by longshore drift so the rocks are smoother and more well-rounded

Question 27

How does the data from the hypothesis “Sediment size will be more angular on the west side” help us answer the question “How effective are the coastal management strategies at Newton Beach?”

Answer 27

shows that the coastal management strategies are effective as as there are more angular rocks on the west side it shows that the sediment is being stopped by the groynes and it is not being transported by longshore drift

Question 28

Data for “Coastal defences at Newton Beach will have an impact on coastal processes”:

Answer 28

Question 29

What is shown in the field sketch for the hypothesis “Coastal defences at Newton Beach will have an impact on coastal processes”?

Answer 29

• From the field sketch the breakwater has protected the bay from the SW prevailing wind, which causes destructive and erosive waves
• This has created a relatively sheltered bay, where deposition has occurred as a wide, gentle beach gradient can be seen
• Sand dunes with colonising marram grass also suggests a relatively stable depositional environment which is held in place by pinning (hard-engineering)
• Erosive processes are not evident in the landscape of the field sketch

Question 30

How does the data for the hypothesis “Coastal defences at Newton Beach will have an impact on coastal processes” help us answer the question “How effective are the coastal management strategies at Newton Beach”?

Answer 30

• Sand dunes with colonising marram grass also suggests a relatively stable depositional environment which is held in place by pinning (hard-engineering)
• Erosive processes are not evident in the landscape of the field sketch - shows coastal management strategies are successful at reducing erosion at Newton Beach

Question 31

Conclusion for the hypothesis “There will be more sediment on the west side of the groynes than the east”:

Answer 31

• We can accept this hypothesis as the beach profile data that we collected shows a difference between the height of the sediment on the west side of the groyne and the east
• On the west, the height of the sediment goes above 2.5m whereas the east side does not go above 2m
• Addtionally, the CSA of the west side is 23.52 m² compared to the east which is 20.48 m²
• This was due to the groynes preventing longshore drift, resulting in the build up of sediment on the west
• These significant differences between the west and east side of the groynes allowed me to to be confident in my conclusion

Question 32

Conclusion for the hypothesis “Sediment size will be larger / more angular on the west side”:

Answer 32

• can accept this hypothesis as the data we collected shows that on the W side the pebble size media is 76mm, whereas on the E it is 89mm
• also on the W side 3 pieces of sediment were classified as very angular compared to none on the E
  
  • due to 7,000km fetch and SW prevailing wind (wind direction)

Question 33

Conclusion for the hypothesis “Coastal defences at Newton Beach will have an impact on coastal processes”:

Answer 33

• We must reject this hypothesis as the data we collected does not support this hypothesis
• The qualitative data that we collected included a field sketch
• Even though the field sketch clearly shows a build up of aa beach and well-established sand dunes it this does not clearly show the impact that the coastal defences has on the coastal processes at Newton Beach

Question 34

How effective are the coastal management strategies at Newton beach?

Answer 34

Somewhat effective as groynes prevented longshore drift of sediment hence explaining why there was a higher beach profile and larger and more angular rocks on the west side than the east side of the groynes

Question 35

Potential problems that may have occurred when collecting data for physical fieldwork enquiry:

Answer 35

• weather - prevailing wind blowing from another direction
• high tide - can’t measure side profile of beach
• time of day - e.g. too dark so can’t see
• time on month - Winter months (more storm + bad weather + more destructive waves)

Question 36

Operator error when collecting data for physical fieldwork enquiry:

Answer 36

ranging poles may not have been pushed in at same depth the whole time when measuring height of beach profiles

Question 37

Measurement error when collecting data for physical fieldwork enquiry:

Answer 37

• well-used ranging poles
• chipped callipers
• need higher resolution to increase accuracy

Question 38

Random error when collecting data for physical fieldwork enquiry:

Answer 38

rocks may be moved and placed in different places by tourists

Question 39

How could we have increased the reliability of the data we collected?

Answer 39

increase sample size

Question 40

How could we have increased the accuracy of the data we collected?

Answer 40

repeat investigation and measure 3 times times to take an average

Question 41

Alternative Primary Data Collection - Longshore drift: direction and strength

Answer 41

1. Select 30-50 pebbles of different shapes and sizes from the beach. Use waterproof paint to mark each pebble
2. Spread the pebbles out in the swash zone, and place a marker further up the beach to show the start point for the pebbles
3. After 20 minutes find as many pebbles as you can, and measure how far each has moved from the start point
4. After 20 minutes, you may find that some of the pebbles will have disappeared from the beach or moved in a different direction to the others
5. This does not mean that your results are ‘wrong’. Record what happened to each pebble (including ‘disappeared’)
6. Repeat the experiment at least 3 times, or until you judge that the running mean for distance travelled by a pebble indicates that you have taken an adequate sample

Question 42

How might this additional data (from the alternative primary data collection - longshore drift: direction and strength) have an impact on the reliability of your conclusions?

Answer 42

Could have been used alongside pebble size to show that erosional processes were responsible for the reduced mean at the middle and eastern sites as longshore drift was visibly apparent