title of geographical enquiry
how are coastal processes shaping the beach at Porlock Bay?
where is Porlock bay
In south-west England, in west Somerset
why was this location suitable for our enquiry
- a site of longshore drift
- coastal processes made an impact at the beaches on either side of bay
- clear difference to compare
what are the steps of a geographical enquiry
- introduction and planning
- methods and data collection
- data presentation and analysis
- conclusion and evaluation
what is longshore drift
the process where waves transport eroded material along a beach in a zigzag motion, and deposit it further down the coast
meaning of tenuous
lacking sound reasoning, weak (a tenuous argument)
name some risks and ways to avoid
Drowning - maintain a 3m distance from the water at all times
Slipping/ twisted ankles - wear appropriate footwear and don’t run
Hypothermia - wear appropriate clothing (thermals, hats), and have an extra layer at all times
Illness from rain - bring a waterproof layer
how does secondary data help plan a coastal fieldwork enquiry
Provides a time-efficient source of information on the wave and wind direction, the geology and the coastal processes of the area. We can use these to choose a location where there will be a clear change in results, dependant on where we are measuring (in this case, a difference in average sediment size and beach profile at the headlands)
what direction is longshore drift going in porlock bay
eastward
name of the headlands at porlock bay
Gore point (west one), Hurlstone point (east one)
How did we measure beach profile
Did stratified for location, and systematic for beach profile itself. We set up a reference point on a reference person for the clinometer. We stationed the reference person 5m up the slope. Measured the angle with the clinometer and wrote it down. Moved the clinometer up 5m, and the reference person up 5m and repeated measuring process. Did this until we reached the top of the slope.
What was our justification for beach profile method
- systematic distancing between measurements eradicated bias
- enabled us to cover the whole slope
- we could compare the beach profiles at either end of bay with same measurements
how did we ensure accurate results for beach profile method
- kept tape measure taut
- used the same person as reference
- used the same person measuring
what were limitations of beach profile method
- would not have gotten minor changes in gradient (no changes within 5m)
how did we measure sediment size
We selected a random rock at regular, systematic intervals and measured the A-axis (longest side) with a calliper. We wrote down the measurements and repeated this process every 5m
justification for sediment size method
allowed us to cover whole slope
reduced bias (random selection)
how did we ensure accuracy for sediment size method
- callipers increase accuracy of measurement (more than a ruler)
- had same person measuring
- used different people to pick rock so it was more random and reduces bias
- measured multiple rocks so there’s a large sample size
what were the limitations of the sediment size method
- only measured one side/axis
- some bias in the fact that people picking rock (instead of computer)
how did we measure sediment shape
We selected a random rock at regular, systematic intervals and used the power’s index of roundness to decided how rounded/ angular. We wrote down the score and repeated this process every 5m
justification for sediment shape method
- allowed us to cover whole slope
- reduces bias (random selection)
- tried to quantify something quite subjective
how did we ensure accuracy/reliability in sediment shape method
- same person judging roundness of rock
- measured multiple pebbles (large sample size)
- different ppl randomly selected pebbles, so less bias
limitations of sediment roundness method
subjective (not a clear scale, based on opinion)
Advantages of random sampling
- can cover larger area
- eradicates bias
disadvantages of random sampling
- can lead to poor representation of population
- may not be time efficient
