The coast at Barton-on-Sea is particularly well-known for its geological content, being home to many fossils. The cliff tops are home to a scenic golf course.
A cliff-top path runs between Barton and the village of Milford on Sea. From there, the Solent path stretches all the way to Emsworth, on the West Sussex border. It is also well known for the fact that it was the first place in England to try out rock groynes.
- Population = 24,500
- Land use = almost all residential area.
- Fact = the area has been designated a ‘Site of Special Scientific Interest’ because of its rock formation.
- Fact = there has been some speculation that the 2007 Kent earthquake may have caused a 300 metre (948ft) crack in a cliff at Barton-on-Sea creating fears of a landslide.
Coastal processes
Fetch
Fetch, often called the fetch length, is a term for the length of water over which a given wind has blown. It is used in geography and meteorology and is usually associated with coastal erosion. It plays a large part in longshore drift as well.
The fetch length along with the wind speed (or strength) determines the size of waves produced. The longer the fetch length and the faster the wind speed, the larger and stronger the wave will be. For example, the fetch for south england comes all the way from south america
The Different types of coastal erosion
Corrasion/abrasion is when waves pick up beach material (e.g. pebbles) and hurl them at the base of a cliff.
When waves hit the base of a cliff air is compressed into cracks. When the wave retreats the air rushes out of the gap. Often this causes cliff material to break away. This process is known as hydraulic action.
Attrition is when waves cause rocks and pebbles to bump into each other and break up.
Corrosion/solution is when certain types of cliff erode as a result of weak acids in the sea.
Longshore Drift
Longshore drift (sometimes known as shore drift, LSD or littoral drift) is a geological process by which sediments such as sand or other materials move along a beach shore. Due to the fetch, the beach sediment is carried downcoast. This process is usually caused by destructive waves. Due to Bournemouth having groynes this process is stopped in this area but the same process carries on down coast in Barton-on-Sea. This results in the beach sediment being taken away from Barton and the cliffs being exposed to the seas.
Constructive waves
Constructive waves bring in sediment fron the sea, otherwise known as a strong swash. The wave doesn’t drag the sediment away because of its weak backwash.
Destructive waves
Destructive waves are totally different. Because the wave breakes onto the sand, it has a weak swash. As it breaks, the wave crashes into the sandand claws back beach sediment.
Coastal management
Groynes
Groynes are wooden, concrete and/or rock barriers or walls at right angles to the sea. Beach material builds up on the updrift side, where Longshore drift is predominately in one direction, creating a wider and a more plentiful beach, therefore enhancing the protection for the coast because the sand material filters and absorbs the wave energy. However, there is a corresponding loss of beach material on the downdrift side, requiring that another groyne be built there. However, groynes do not protect the beach against storm-driven waves and if placed too close together will create currents, which will carry sand material offshore.
Groynes are extremely cost-effective coastal defence measures, requiring little maintenance, and are one of the most common coastal defence structures. However, groynes are increasingly viewed as detrimental to the aesthetics of the coastline, and face strong opposition in many coastal communities.
Cost – est. at £200,000 per groyne
Beach Nourishment
Beach nourishment or replenishment is one of the most popular soft engineering techniques of coastal defence management schemes. This involves importing alien sand of the beach and piling it on top of the existing sand, the imported sand must be of a similar quality to the existing beach material so it can integrate with the natural processes occurring there, without causing any adverse effects. Beach nourishment can be used along side the groyne schemes. The scheme requires constant maintenance: 1 to 10 year life before first major recharge.
The limitations of beach nourishment are the re-application because it is reclaimed by the sea via longshore drift.
Cost – est. £5,000-£200,000 per square100m, plus control structures, ongoing management and minor works.
Rock Armour And Sea Walls
The main difference between rock armour and seawalls is that rock armour is permeable. It is this permeability that allows it to dissipate the energy of storm waves and prevent erosion. A similar effect may be created through the use of precast concrete units that are designed to be permeable.
Cost - High, but with relatively low maintenance (£100,000-£300,000/100m length)
Section 2:Methodology
Section 4: Data Interpretation
Key Questions
1). How are the areas of Bournemouth and Barton–on Sea currently managed?
Bournemouth is managed by wooden groynes and beach nourishment which protects the sediment from longshore drift, thus keeping beach full. Barton-on-Sea has coastal protection for an entirely different reason. Due to Bournemouth’s greediness, Barton is starved of sediment so its cliffs are at the mercy of the cliffs. Barton has rock armour and rock groynes. The data used comes from the Bi-Polar scores because it shows my opinion on the various issues in both areas.
2). Why Do Bournemouth And Barton-on-Sea have different forms of coastal defence?
Bournemouth’s method is superior to Barton’s because of the financial gap between the two areas. Also because the need the defence for different reasons i.e. Barton for defending its cliffs and Bournemouth for protecting its beach. The data I used for this question came from my questionnaire results as it showed the opinions of some of the visitors or local residents. I also used my Bi-Polar for a subjective view.
3). Is the current coastal management sustainable?
In Bournemouth yes, because the current strategies are working very well and they are investing in new defences i.e. the underwater artificial reef at Boscombe. In Barton no, because the current strategies there are failing fast. Lots more land sliding have caused some areas of the Barton coastal path to be closed off to the public. I think the most sustainable method is the beach nourishment at Bournemouth because it has had the most effect on its area than the other techniques. I used my Bi-Polar data to evaluate the current coastal management techniques.
4). In what ways are Barton-on-Sea disadvantaged in tourism due to Bournemouth’s ‘collection’ of beach sediment?
Due to the coastal erosion, Barton’s only strong point, its beach, is a sorry-looking sight. The beach is almost non-existent with the cliff slumping reveals rough, dirty cliffs. The aesthetic value is very low and this lets down the town as it calls itself a ‘seaside resort’. I used my Bi-Polar because it shows a subjective view. I also used my questionnaire to get peoples opinions.
Section 5: Evaluation
The Limitations of the results
Cost Benefit Analysis
The results can be affected by the opinion of the person asked, otherwise known as a subjective view. This makes them unreliable.
Environmental Survey
These results are totally subjective due to the approach of collecting the results. This means the data could be unreliable
Bi-Polar Analysis
Again, the bi-polar analysis is a subjective view, just like the environmental survey.
Questionnaire
The questionnaire involved asking 50 people a set questionnaire as well as a few of your own personal questions. Again this is a subjective method because it collects the opinions of the people in the study area.
Answering the key questions
1). How are the areas of Bournemouth and Barton–on Sea currently managed?
Bournemouth is managed by wooden groynes and beach nourishment which protects the sediment from longshore drift, thus keeping beach full. Barton-on-Sea has coastal protection for an entirely different reason. Due to Bournemouth’s greediness, Barton is starved of sediment so its cliffs are at the mercy of the cliffs. Barton has rock armour and rock groynes.
2). Why Do Bournemouth And Barton-on-Sea have different forms of coastal defence?
Bournemouth’s method is superior to Barton’s because of the financial gap between the two areas. Also because the need the defence for different reasons i.e. Barton for defending its cliffs and Bournemouth for protecting its beach.
3). Is the current coastal management sustainable?
In Bournemouth yes, because the current strategies are working very well and they are investing in new defences i.e. The underwater artificial reef at Boscombe. In Barton no, because the current strategies there are failing fast. Lots more land sliding have caused some areas of the Barton coastal path to be closed off to the public..
4). In what ways are Barton-on-Sea disadvantaged in tourism due to Bournemouth’s ‘collection’ of beach sediment?
Due to the coastal erosion, Barton’s only strong point, its beach, is a sorry-looking sight. The beach is almost non-existent with the cliff slumping reveals rough, dirty cliffs. The aesthetic value is very low and this lets down the town as it calls itself a ‘seaside resort’.
Evaluation
Bournemouth is thriving from its trapped beach nourishment. Its full beach attracting hundreds of thousands of people all year round to its area, boosting the local economy.
Barton-on-Sea on the other hand is trapped in a vicious circle. How ever much they spend on coastal protection they will still lose there cliffs through the lack of beach nourishment.
Bournemouth has a huge upper hand over Barton and will always ‘call the shots’ due to its coastal defence strategies.