Coastal Practical Skills (Edexcel IGCSE Geography): Revision Note

Aims, sampling, equipment & risk assessment

Coastal fieldwork enquiry

• To undertake a coastal fieldwork enquiry there are a range of practical skills and methods that will be used

• These can be applied to any coastal fieldwork

• The fieldwork enquiry should be linked to geographical theory and/or example:

  • In the coastal fieldwork enquiry the theories of how coastlines vary in terms of their processes, landforms and/or the effectiveness of management strategies

Aims and hypothesis

• The aims and hypothesis come from general questions asked about the coast such as:

  • Does geology affect the shape of a stretch of coastline and its landforms?

  • How and why is hard engineering more effective along a particular stretch of coastline?

  • How and why is soft engineering used along a stretch of coastline?

  • Does beach morphology change because of wave energy?

  • Does coastal protection along a stretch of beach consider stakeholder views?

• Aims are focused on a particular place as you cannot measure everywhere

• Examples of an aim would be: 

  • To explore the impact of coastal processes on Y beach 

  • To investigate how wave energy along X beach changes beach morphology

  • To explore how geology affects the shape and landforms of W beach

• Hypotheses are statements that are tested through fieldwork

• Examples of a hypothesis would be:

  • Coastal management strategies used at beach Y have taken conflicting views into account

• A null hypothesis is a statement that is opposite to a hypothesis 

• This ensures there is no bias when collecting the evidence

  • You are not ignoring evidence because it doesn't prove the statement

• If you cannot prove the statement then the opposite must be true

• Examples of a null hypothesis would be:

  • Coastal management strategies used at beach Y have not taken conflicting views into account

• After the aims and hypothesis of the fieldwork have been established the next steps include:

  • Select the sites - this will involve sampling

  • Decide on the equipment to be used

  • Consider health and safety issues - complete a risk assessment

  • Data collection methods to be used

Site selection and sampling

• It is not practical or feasible to collect data along all parts of the coast as there would be too much data

• To select coastal sites, getting a true sample reduces bias

• There may be situations where access to a stretch of the coast is limited due to a rock fall or unstable cliffs etc.

• Therefore, an opportunistic approach to sampling needs to be taken

• This needs to be as close as possible to the site selected using sampling 

• The most commonly used sampling strategies for a coastal enquiry are:

  • systematic - sampling of sites at regular intervals means that all parts of the stretch of coast are covered

  • random - the use of random sampling means that all sites have an equal chance of being selected which eliminates bias

  • stratified - by dividing each sampling site into groups e.g. three sites from each sample section

• Site location can be recorded using GPS to give an accurate location using latitude and longitude

• Or through grid reference from an Ordnance Survey map

Equipment

• To complete the coast measurements a range of equipment is needed 

• The equipment includes the following:

  • Surveyor’s 25+ meter tape - measuring distances on a beach or between ranging poles when completing beach transects

  • Compass to measure direction

  • Ranging poles for beach transects

  • Clinometer - calculate the angle of a beach

  • Callipers - measuring pebble size

  • Quadrat - used to select sediment for sampling

  • Clipboard for holding recording sheets

  • Recording sheets

  • Roundness or angularity charts 

  • Pencil for writing in data, particularly useful if the paper becomes damp

  • Camera to take photographs of sites and coastal features

Risk assessment

• Any fieldwork will involve consideration of health and safety using a risk assessment

• Risks associated specifically with coastal fieldwork may include:

  • tide times

  • weather conditions

  • slippery rocks

  • polluted water

  • working in an unfamiliar place

  • misuse of equipment

Using equipment in the field

Data collection methods

• The data collection methods will depend on the aims/hypothesis of the fieldwork

• The starting point with most coastal fieldwork is a question on 'what is needed to answer the enquiry question?'

• Data collection should include both quantitative and qualitative methods

• The collection of quantitative data can be completed in several ways in a coastal study

Beach profile

• Beach profiles use distance and angle measurements to identify the shape of the beach

• Follow a transect line from the edge of the sea to the end of the  beach

• Split the line into segments where the slope angle changes

• Each reading is taken from one break in a slope to the next break of the slope

  • Student A stands, at a safe distance from the edge of the sea, holding a ranging pole

  • Student B stands holding a second ranging pole, further up the beach where there is a break of slope

  • Measure the distance between the two ranging poles using a tape measure

  • Measure the angle between the matching markers on the ranging pole using a clinometer

  • Repeat the process at each slope break until you reach the top of the beach

Sediment analysis

• Sediment analysis is used to examine how beach material is sorted across the width of a beach

  • This links to longshore drift processes

• Depending on the size of the sediment being measured, random, systematic and/or stratified sampling is used to take a sample of beach sediments (such as sand, gravel and pebbles)

• The sediment is measured at the beach using callipers to measure the axes of each pebble

• The a-axis is the shortest axis

• The b-axis is the widest axis at right angles to the c-axis

• The c-axis is the longest axis

Measuring pebble shape

• The easiest way to measure pebble shape is to classify the stone as either very angular, angular, sub-angular, sub-rounded, rounded or very rounded using a Power’s Scale of Roundness

• This is judged by eye

• Using a card with a concentric circle or a protractor, measure the minimum radius of curvature

• This is the sharpest corner on the c-axis

Measuring longshore drift

• Choose 25 to 40 pebbles of various shapes and sizes from the beach

• Using waterproof paint, mark each pebble so you can identify them

• Spread the pebbles out in the swash zone, and place a marker to show the start point for the pebbles

• Using a stopwatch, wait for 20 minutes then search for as many pebbles as you can 

• Measure how far each has travelled from the start point

• Some of the pebbles may have disappeared from the beach or gone off in a different direction, but it doesn't mean that your results are ‘wrong’

• Record what happened to each pebble (including ‘disappeared’)

• Repeat the process 3 times, or until you judge that the 'mean' for the distance travelled by a pebble indicates that you have taken an adequate sample

Measuring groynes

• Use a tape measure and find the height of beach material on either side of a groyne

• Measure a minimum of three heights along the beach profile of each groyne

• Compare a series of groynes along the length of the beach

Measuring rip-rap

• Rip-rap or rock armour data can be used to measure the effectiveness of coastal defence

• Use a measuring tape to measure the length, height and width of each boulder

• Measure the angle of the boulder and note if the widest face is facing straight into oncoming waves or at an angle

Photographs and field sketches

• Photographs and field sketches are qualitative data 

• Just as with any data collection and presentation they have strengths and weaknesses

• In a coastal environment enquiry, photographs and field sketches can be used to show landforms and particular features such as beach slope

• Photographs are also ideal for illustrating the data collection methods used