Physical Fieldwork- Dawlish Warren Flashcards
(18 cards)
TITLE
Investigating the effects of natural processes and human management on Dawlish Warren
Location
Dawlish Warren is located in the South West of England in Devon
On the western bank of the River Exe opposite Exmouth at the mouth of the river.
Hypothesis 1
Dawlish Warren is a low energy environment
Hypothesis 2
Lonshore drift operates from west to east
Hypothesis 3
The beach narrows near the distal end of the spit
Hypothesis 4
Coastal engineering strategies are effective
Explain the advantage(s) of the location used for your fieldwork enquiry
(2)
manageable in one day as the spit was a small size
easily travelled distance as only 1 hr away with accessible caoch parking
Risk Assessment
We collected data at Groyne 1, 4 ,7, 10 ,13
the sea and drowning = only collecting data on a falling tide and only teachers went into the water
exposure to the elements resulting in heatstroke or hypothermia = look at the weather forecast and dress appropriately with hats or coats
Methodology:
Wave frequency
count the number of waves breaking on the shore in 60 seconds. Tally score
repeat X3 to reduce anomolous data
Dawlish Warren is a LEE
+ve easily collected data, no complex equipment
-ve room for human error as counting could be wrong
Methodology:
Longshore drift
1 person throws an orange into the swash and stands in line with it on the beach
it stays in the water for 60 sec
2nd person walks in line with the orange and stops at 60s where it reached
a staff member collects the orange from the sea
3rd member uses a measuring tape to measure the distance between person 1 and 2
Repeat X3
Longshore drift operates from West to East
-ve throwing the orange at different points into the wave may distort results
Methodology:
Beach profile
person 1 stands on sand next to sea
person 2 travels 5m up the beach or until gradient changes
person 1 levels the clinometer at 2nd person’s top of head reading the angle
repeat until reached the beach end
The beach narrows towards the distal end of the spit
use 2 people of same height to reduce errors in angle from height difference
-ve the person holding the clinometer may innacurately read the angle
Methodology:
Bi-polar survey
fill out the survey at different aspects of the Hard or Soft engineering strategy.
calculate the total and mean score
Groyne, Sand dune replenishment, Geo tubes, Sea wall
Caostal engineering startegies are effective
+ve scores for each strategy can be easily compared
-ve subjective and based on opinion reducing validity of results
CAN ALSO BE USED AS THE CASE STUDY FOR COASTAL DEFENCE SCHEMES
Data presentation
Located Beach profiles
Located LSD proportional arrows
wave frequency bar graph
bi-polar divergent bar graph
Located Beach profiles:
the gradient is drawn using a protractor and the scale is drawn for each meter until the side profile of the beach is made and how long the width of the beach is 1mm=1m
next to the groyne on the map
Located LSD proportional arrows:
each arrow is the same length with the length following a scale of 1cm=1m
next to the groyne on the map
they also show the direction of orange movement
wave frequency bar graph:
each groyne had a bar
bi-polar divergent bar graph:
The strategy was graded in 10 sections from -3 to 3 with the most positive result being most effective all colour coded
State the title of your physical enquiry and why it was suitable
(2)
investigating the effects of natural processes and human management at Dawlish Warren
it was suitable as recently there had been new beach management schemes built such as geo tubes = plenty of defences to analyse
Justify the use of one of the following in your enquiry:
Maps <-
Photos
Field sketches
Maps
-navigate to primary data collection sites = stops us getting lost in unfamiliar coastal terrain
-show the location of the enquiry = giving clear visual representation of the 5 data collection sites along the spit
-plot data on = locate beach profiles and spot easy visual patterns
Assess how effective your presentation techniques were
(6)
Located beach profiles:
+ve drawn to scale and easily highlights the gradient of the beach allowing for comparison, locating on the OS map let changes along the spit become visible
-ve hard to hand draw so errors may have been made so profiles are incorrect and misrepresnt the beach gradient
Located LSD proportional arrows:
+ve effective at presenting LSD data as they convey the distance and direction the orange travelled
-ve not as effective for sites that recorded different directions of orange movement across the 3 tests, this would have needed double headed arrows making the data presentation cluttered and difficult to read.
Bi-polar divergent bar graph:
+ve allowed for a range to be calculated and easy to see if a section was positive or negative
Overall the data presentation techniques were generally effective
Conclusions
Dawlish Warren is a LEE:
TRUE OVERALL
-the waves were lapping constructive waves and conditions were calm with long wavelengths
The beach narrows towards the distal end of the spit
DISPROVEN OVERALL
-the set of beach profile data was inconclusive with groyne 10 being the 2nd widest at 30m despite being at the distal end
LSD operates from West to East
TRUE OVERALL
-during all our LSD tests the orange travelled from West to East for groynes 1, 4, 7 ,10, 13
Coastal engineering strategies are effective
TRUE OVERALL
-sand dune restoration
-sea wall
-geo tubes
-RipRap
Most strategies were +ve on the bi-polar analysis
-groynes being effective against erosion and sand dunes being good at maintaining natural habitats and processes
-with the sea wall being most effective against overtopping at a score of +3 for that section
