Case Study: Dorset

Dorset is a county in the south of England, which has a variety of landforms along its coastline. This case study can help you find examples of both erosional and depositional landforms that you can draw on as evidence in your exam.

Swanage is an area of Dorset that has a variety of landforms along its coastline, most of which are due to its varied geology.

Studland Bay 

Studland Bay has incredible sandy beaches, which draw in tourists from across the UK. The Bay has formed due to rapid erosion, a stark contrast to its neighbour, Ballard Point, which is a headland. 

It is composed of clay and sand, similar to Swanage Bay. This composition results in very little resistance to erosion there, helping the bay form and producing its sandy beach.

Ballard Point

Ballard Point is a headland that sits between Studland Bay and Swanage Bay. The headland is made up of far stronger rock than the two bays, which has led to it dramatically extending out from the mainland, while the bays retreat. 

Ballard Point is made of chalk, which is extremely resistant to erosion, unlike the clay that forms the geology of the Bays. Notably, erosion has helped caves form in the headland, which helps house local wildlife. 

Old Harry and His Wife

Between Studland and Swanage Bays lies the Foreland, a headland composed of chalk, which is a hard rock. Here, erosion and weathering have sculpted distinctive features. 

Old Harry, as it is known, is a stack while his wife is a stump. The rock was strong enough to form an arch, which collapsed and transformed into a stack and a stump.

Chemical, mechanical and biological weathering, including the action of vegetation, contribute to the gradual breakdown of these structures.

Swanage Bay

Swanage Bay has formed between two headlands. This is because the two headlands are formed of hard, resistant rock, while the Bay’s clay and sands erode at a much faster rate. The Bay faces rapid erosion that changes the geography of the area over time. The sandy beach is a favourite for tourists, although even that is under threat. 

  • Clay Cliffs – The cliffs bordering Swanage Bay are composed of soft clay, a rock vulnerable to erosion. Vegetation covers the bay’s northern end, protecting the cliffs from erosion. However, wet weather weakens the cliffs in other areas lacking vegetation, leading to slumps and mass movements.
  • Longshore Drift – A main process in Swanage Bay is longshore drift, which transports gravel from the south to the north, gradually causing the beach to lose material year after year.

Durlston Head

Durlston Head is another headland, to the south of Swanage Bay. It is made up of limestone, a very resistant and strong rock. Durlston head presents a contrast to Swanage Bay and helps give the Swanage coastline its distinctive pattern of Bay-Headland-Bay-Headland. 

The beaches at Durlston Head are rocky, rather than sandy, due to the mass movement of materials from the cliff. The beaches are less accessible, and tourists tend to prefer a hike rather than a relaxing sit on the beach. 

Chesil Beach

To the West of Swanage, near Weymouth, you can see the distinctive feature that is Chesil Beach. 

Chesil Beach is an example of a tombolo, as it is a spit that connects the Isle of Portland to the mainland.

Created by the relentless action of longshore drift, Chesil Beach traps and transports sediment, forming a protective barrier between the mainland and the island. Behind the beach lies a lagoon known as The Fleet Lagoon.

Factors affecting the shaping of the landscape

Climate and Geology – The rate of coastal land-shaping processes is largely determined by both the climate conditions and the type of rock formations beneath the surface. The presence of softer rocks, their susceptibility to erosion and changing weather patterns impact the rates of erosion.

Human Activity and Coastal Management – Human interventions such as coastal management strategies interact with natural processes to shape the coastal landscape. For example:

  • Groynes, which are barriers perpendicular to the coast, trap sediment to create larger beaches, reducing erosion rates.
  • Sea walls reflect waves but lead to a strong backwash, removing sediment from the beach.
  • Beach replenishment efforts widen and add sediment to widen the beach, protecting against erosion.