coastal fieldwork

Question 1

hypotheses, conclusion and evidence for shingle ridge

Answer 1

hypotheses: the shingle ridge is steeper on the east side of the beach
conclusion: the shingle ridge is somewhat steeper on the east side of the beach
evidence: in the east the maximum slope angle is 35 degrees. in the west it only reaches 22 degrees. finding somewhat supports hypothesis

Question 2

data collection for shingle ridge

Answer 2

data collection: used a clinometer and pointed it at the same place on the same place at one person at 5m intervals.
advantages:
- clinometer- accurate.
- beach profile transects spaced at 5m intervals (systematic sampling)- quite representative data, because of good coverage
disadvantages:
- because of systematic sampling, not all variations between transects captured, limiting representation
- clinometer- difficult to use precisely in windy conditions, better to use poles. so beach gradient not entirely accurate
- measuring tape- not held taught because of windy conditions, distance measured inaccurately.

Question 3

data presentation and analysis for shingle ridge

Answer 3

beach profiles drawn onto the same graph, so easy visual comparison- immediately see which side is bigger and by how much
clearly see differences
generalisation, doesn’t allow for nuances

Question 4

hypotheses, conclusion and evidence for sediment size

Answer 4

hypothesis: sediment size is smaller on the east side of the beach
conclusion: sediment size is much bigger on the west side of the beach than on the east side of the beach
evidence: avg sediment size much bigger on west side (median = 13.5cm) than on east side (median = 4.4cm). strongly supports hypothesis with a difference of 9.1cm

Question 5

data collection for sediment size

Answer 5

data collection: used callipers, on the long axis with random and stratified sampling
advantages:
- callipers- accurate data readings because stone held tightly in place and precise because it shows measurements to 1mm
- large sample size of 100+ after groups collated data, makes it representative
- stratified sampling- efficient strategy, wanted to measure start to end of longshore drift
- random sampling- used a random number generator and a grid, reduce bias and increase reliability
disadvantages:
- long-axis measurements doesn’t allow for most accurate measurements, only captures one dimension. to improve, measure other dimensions
- random sampling- at each grid there were a number of rocks, so bias was likely introduced there

Question 6

data presentation and analysis for sediment size

Answer 6

presentation: dispersion graphs clear, visual way of comparing spread of data at both sides of beaches. same graph and scale, immediately see results and differences- east has larger range of pebble sizes.
proportional symbols map shows immediately and clearly mean pebble size is bigger on the west side of the beach
analysis: calculating mean- allows us to summarise data clearly in a statistic and get rid of anomalies
calculating IQR allows us to identify bigger range of data in east compared to west, more complex than mean suggests

Question 7

hypotheses, conclusion and evidence for sediment shape

Answer 7

hypothesis: sediment shape is rounder on the east side of the beach
conclusion: sediment size overall rounder on east side of the beach than on west
evidence: in east, there are 30 very round pebbles, in west only 5 very round pebbles. strongly supports our hypothesis

Question 8

data collection for sediment shape

Answer 8

data collection: used power’s scale of roundness to judge sediment shape, with random sampling (grid method) and stratified sampling
advantages:
- stratified sampling- efficient strategy, wanted to measure start to end of longshore drift
- random sampling- used a random number generator and a grid, reduce bias and increase reliability
disadvantages:
- random sampling- at each grid there were a number of rocks, so bias was likely introduced there
- power’s scale of roundness very objective, makes it unreliable. to improve- same person making all the judgements to increase consistency, group decides by consensus

Question 9

data presentation and analysis for sediment shape

Answer 9

radial graphs for sediment shape provide a clear comparison of frequency and spread of different categories of sediment roundness

Question 10

field sketches

Answer 10

advantages:
- useful compared to photos, emphasise relevant features and processes
disadvantages:
- very subjective, leads to unreliability

Question 11

primary data

Answer 11

sediment shape
sediment size
beach profile
annotated field sketch

Question 12

secondary data

Answer 12

rose diagram showing wave direction