physical fieldwork

State the aim / title of your fieldwork enquiry.

How has Longshore Drift affected the morphology of Solent Beach?

Identify your hypothesis (es).

1. The beach will get wider from west to east along Solent Beach

2. The pebble size gets smaller and more rounded from west to east along Solent Beach.

Explain why this is a suitable topic for a geographical enquiry.

The process of LSD is accessible in theory and easy to understand.

You can easily collect primary data.

There are many places along the coastline in the UK where you can study this topic

Outline the theory and / or concepts underpinning the fieldwork. Include key terms.

Longshore Drift Theory

As the prevailing wind direction approaches the shore at an angle so do the waves.

The incoming swash of the waves comes into the beach at an angle, however the subsequent backwash is dragged back out perpendicular to the shore.

Sediment carried by the waves is brought in at an angle and transported out perpendicular to the shore. This process repeats so that sediment is carried in a zig zag fashion along the beach.

Similarly, the waves have the most energy at the beginning of the process and less at the end. This means that the waves are able to carry larger sediment at the beginning (west) and only smaller sediment at the end (east). So they deposit larger sediment first and gradually smaller as they lose energy.  This means that the beach sediment size  is likely to be graded from one end to the other  with large sediment at the south and small at the north.

Describe the location of the fieldwork

Solent Beach in Hengistbury Head. This is located on the South Coast in Dorset near to the town of Christchurch.

Justify why this was a suitable location (explain the advantages of the area where you went to).

1. It is a stretch of coastline which has evidence of longshore drift (transportation), erosion and deposition.

2. It is easily accessible due to safe parking facilities and access onto the beach. Also, clear walking footpaths that get you from visitors centre to the beach

3. It is in an area within travelling distance of the field study centre so we could stay there all day.

4. It is an area of great natural beauty

5. There is a Visitors centre near the beach offering infrastructure.

Suggest why risk assessment is important when carrying our fieldwork and what were the risks and how were they managed?

1. Drowning – risk level 9/10.

How could you reduce the risk. Do not go in the water and stay clear of the edge.

1. Trips, slips & falls – risk level 5/10 How could you reduce the risk. Wear appropriate footwear. Don’t run. Look where you are going.

2. Injury from animals, pet dogs or wild animals, stings from sea life. Do not interact or interfere with animals. Do not go off the path.

3. Danger from strangers including theft or mugging. Be polite and respectful of others and be aware of your surroundings and belongings.

4. Dehydration, sunburn and heat stroke if hot. Hypothermia if cold. Check weather forecast and wear appropriate clothing/ equipment.

Identify your methods of primary data collection and state whether they are quantitative (Qt)or qualitative (Ql).

 

Primary Data - data we have collected ourselves

Secondary Data – data someone else has collected

Qualitative Data - data that is descriptive (subjective)

Quantitative Data – data that is numerical (objective)

Beach profile: QuantitativeTo measure the width of the beach from site 1 -6 and the angle of the beach from the foreshore to backshore.  If the beach gets bigger going East this will suggest LSD as sediment will have been transported from the south at Start point and deposited at the Northern end of the beach

Sediment Size: Quantitative Select random pebbles using a quadrat choosing 5 samples from the corners and the centre. If sediment size gets smaller going East this will suggest LSD as the sediment will have been sorted and graded. This is because the waves will be able to transport finer sediment further as it requires less energy. As the waves travel north their energy reduces and so they drop their load?..

method of beach profile

Beach Profile Follow a straight transect line from the edge of the sea to the end of the active beach. Split the line into segments where the slope angle changes. Each reading is taken from break of slope to break of slope.

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

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

•The distance between the two ranging poles is measured using a tape measure

•The angle between matching markers on each ranging pole is measured using a clinometer

•Repeat this process at each break of slope until the top of the beach is reached.

• From this data the beach profiles can be drawn and the cross sectional area calculated for each site

Advantages of beach profile

• Allows us to quickly and easily measure width and gradient ot beach

• Can find averages for trends

• Simple way of collecting enough data to present in graph

• Easy to use equipment

• Quick and east to do in the day we had

disadvantages of beach profile

• Chance of human inaccuracies as different groups collecting different data for different profiles

• Equipment can be used inaccurately.

• Sometimes people not exactly the same height and hard to see gradient change in the sand when it is quite shallow

method of sediment size

1. Using quadrants select 5 pebbles, taking one from each corner and one from the middle at the first transect site closest to the sea.

2. For each pebble measure the longest axis using callipers

3. Find the average pebble size but adding up all the sizes and divide by 5. Record your results in ArcGIS survey programme on phone.

Repeated at the start of each transect.

Advantages of sediment size

Advantages

• It is simple and quick way to select the rocks to measure in order to find an average

• The quadrat is easy equipment to access or could be made with string and a frame

• Helps geographers help understand sediment sizes from across a beach.

• Lightweight equipment to carry along a beach. 

• Consistent measuring with the longest axis being measured

• Randomised selection using quadrant reduces bias

disadvantages of methods of sediment size collection

Disadvantages

• There could be bias, people tend to choose the rocks that are prettiest or similar in size

• If the person is blindfolded to try and eliminate bias they're still likely to pick up the biggest pebbles

• Measuring can be difficult/inaccurate with a round object

• doesn't cover a large span of testing site

• helps show the effect of LSD on sediment that makes up the morphology of the beach

advantages for photographs

The use of photographs can help provide a visual presentation to better understand the physical geography of an area when descriptions cannot be fully useful.

disadvantages of photographs

Disadvantage

Only a snapshot of one area and at one point in time so they do not show full representation of the area.

Person taking the photo selects what to focus on, so can be biased to show a particular vision/make appoint.

 

Maps are vital to find your way around the beach that you are studying, and without them field work would be much more difficult. Maps help you plan where the sites will be and give you landmarks to measure out your 200m gaps.

field sketch methods

Decide on a frame you want to draw and the purpose of your field sketch. Sketch the background and foreground of the area

• draw features/objects as seen

• label relevant features and add notes/annotations

• include title and information e.g. date, time, place

Advantages of field sketches

• develops ability to record and observe important information by taking time to view and understand the landscape while sketching

• allows you to add notes directly onto the sketch

• easier to label important information

disadvantages of field sketches

• requires more time than taking a photograph

• a sketch doesn't show changes over time