The enquiry title is: “How effective is Coastal Management at Walton-on-the Naze?”
2. Hypothesis: what were you trying to prove?
The investigation aimed to find out whether different coastal management schemes were working to stop longshore drift and erosion.
3. What risks were there?
The paths and steps coming down the cliff were very steep, creating a risk of slipping.
Getting too close to the cliff edge created a risk if the cliff collapsed.
The clay wave-cut platform could be slippery.
The incoming tide could catch people out on the beach.
Sunburn was another identified risk.
4. How did you try to eliminate those risks?
The group went slowly in single file and wore appropriate shoes on the steep paths and steps.
People were not allowed near the cliff edge with the ranging poles (marked poles used as measurement reference points).
The group checked tide tables and left the beach before the tide came in.
Sunscreen was used to reduce the risk of sunburn.
5. Why use maps, photographs and field sketches?
Maps were used to locate the sites.
Photographs and field sketches highlighted possible problems and good points for each type of coastal management.
6. Data collection 1: method and link to the question
A measuring tape was pulled tightly between the pillbox (a small concrete wartime defence building) on the beach and the base of the cliff. The distance was measured in metres and recorded.
The pillbox had been built on the cliffs during the Second World War. As the cliffs collapsed, the pillbox ended up on the beach.
The distance between the cliff and the pillbox was used to investigate cliff retreat. Secondary data allowed comparisons between years to see whether erosion rates stayed the same.
7. Data collection 2: method and link to the question
The intended cliff-angle method used two ranging poles and a clinometer (an instrument for measuring slope angles). One pole was held at the top of the cliff in the area to be measured.
The other pole was placed vertically at the base, roughly in line with the upper pole.
The observer held the clinometer at a comfortable marked point on the lower pole, looked towards the same point on the upper pole and recorded the angle.
The investigation compared the unprotected cliff with the area where the cliff had been regraded (reshaped to a gentler slope). The expected pattern was a steeper unprotected cliff and a gentler regraded cliff.
A steeper angle in the unprotected area was intended as evidence of erosion, but safety problems made those angle measurements unreliable.
8. How effective was your data collection?
The unprotected cliff was too unstable for people to stand at the top with a ranging pole. The angles for those three areas could not therefore be measured accurately.
The original position of the pillbox was not known exactly. Its present distance from the cliff was not an exact measurement of all erosion since construction, although measurements from different years could be compared.
A tape that was not pulled tight gave an inaccurate distance measurement.
9. Data presentation 1: method and reason
A scattergraph presented the cliff-angle results. Sites were placed along the horizontal axis and cliff angle on the vertical axis so that the largest angle could be identified and sites compared. Here the sites are categories; dots compare their angles rather than testing a correlation between two measured numerical variables.
10. Data presentation 2: method and reason
A scaled diagram showed the distance between the cliff and the pillbox. Lines from the secondary data showed earlier cliff positions.
This was intended to make the results clear and show which years had experienced more erosion.
11. What were the results of your investigation?
The management map distinguished protected and unprotected beach. South of the tower, a sea wall protected the cliff and the houses at Sunny Point.
The cliff had been regraded, although the regraded area was not visible during the mapped observation.
The map showed groynes intended to reduce longshore drift and a breakwater at the start of Crag Walk.
Crag Walk was described as a large area of rip rap (large rocks placed as armour) beneath the tower, protecting the base of the cliff from erosion.
North of the tower, the cliff was unprotected. Two pillboxes that had once been on the cliff were now on the beach; this contrast helped judge the management strategies.
The annotated photograph showed a concrete sea wall with no visible sign of breaking down. It stood below the regraded cliff.
The regraded cliff had well-established vegetation and no visible sign of erosion in the photograph.
Drainage holes in the sea wall allowed water from the soil and rock in the regraded cliff to drain away. There was no visible evidence of slumping, supporting the judgement that these measures were effective at the observed location. A photograph is a snapshot and does not show how the slope behaves during every storm or over many years.
The angles 16°, 18°, 21° and 25° are illustrative examples, not actual fieldwork measurements. Actual cliff angles, the second pillbox angle and the protected–unprotected difference are not available here.
The intended results comparison was that the protected cliff had a gentler angle than the unprotected cliff. A numerical comparison needs actual measurements; example angles cannot be used as results.
The measured pillbox-to-cliff distance was 59.85 m, compared with 57.10 m in 2022. The difference between these measurements is 2.75 m over one year.
The distance in 2013 was 41.80 m. Using these distances, 59.85 − 41.80 = 18.05 m of retreat over ten years; 18.05 ÷ 10 = 1.805 m per year, or about 1.8 m per year.
12. Did you meet the aims of your investigation?
The conclusion was that the sea wall and Crag Walk rock armour protected the cliff from erosion.
The groynes were judged less effective at preventing longshore drift because they were not maintained well.
13. How would you improve your investigation?
The cliff-angle method needed better accuracy. Safety restrictions prevented measurements at the cliff edge, so the investigation could not confidently conclude that the measured steepness was caused by erosion.
The pillboxes' original distance behind the cliff edge was unknown. The investigation could not be certain of total retreat since they were built or an erosion rate based on that unknown starting position.
Compare measurements across the last ten years to investigate recent erosion rates, checking the calculations and measurement accuracy.
Test yourself
40 questions · Random sets of 10. These quick checks support revision; practise longer explanations and justified judgements too.
Mr Kidman's Classroom
