UK Landscape Case Studies: Geomorphic Processes and Landforms

Two distinctive UK landscapes

The Dorset coast in southern England and the River Tees basin in northern England show how moving water creates different landscapes. Waves shape Dorset's cliffs and beaches; river water shapes the Tees's valleys and channel. Both contain landforms made by erosion and by deposition.

The Dorset coastline forms part of the Jurassic Coast, which extends for about 155 km from Exmouth in Devon to Poole in Dorset. Its distinctive features include limestone arches, chalk stacks, sheltered bays and shingle beaches.

The River Tees begins at Cross Fell in the Pennines and flows about 130 km to the North Sea at Teesside. Its drainage basin covers approximately 1,800 km². The basin is more than the main river: it includes the surrounding land and tributaries that supply water to it.

Dorset: headlands and bays with contrasting shapes

A headland projects into the sea, whereas a bay is an indentation in the coastline. Around Swanage Bay and Studland Bay, less resistant sandstone and clay are eroded more readily than the harder chalk of The Foreland, the headland between them. The softer sections retreat further, leaving the resistant headland projecting seawards.

This is differential erosion: neighbouring rocks are worn away at different rates. It helps explain why the coastline is irregular rather than a straight line. Although beaches occupy the bays, their sediment is still moved by waves. At Swanage, longshore drift carries beach material from south to north, so deposition does not mean that a beach is permanent or unchanging.

Lulworth Cove: a narrow entrance opening into a bay

Lulworth Cove is a small bay formed where waves breached a resistant band of limestone. Once water could reach the softer clay behind it, that material was eroded more readily and the bay widened inland.

The entrance remains narrow because the limestone is more resistant than the clay behind it. The contrast between the small opening and the wider bay is therefore a visible result of different erosion rates, not simply a difference in wave direction.

The schematic isolates the key relationship: a breach in the resistant outer rock allows erosion to spread through the less resistant material behind it. It explains the shape of the cove without representing a surveyed map of its shoreline.

Durdle Door and Old Harry: erosion through rock

Durdle Door is a natural arch in a limestone headland. Wave erosion enlarged a crack into a cave, then continued until an opening passed through the rock. Its opening lies unusually parallel to the coastline. The arch is an erosional landform: rock has been removed to create the opening.

At The Foreland, the chalk headland has developed caves, arches and isolated remnants. Old Harry is a stack: a pillar of rock separated from the headland after an arch collapsed. Old Harry's Wife is a stump, a much lower remnant produced by further erosion and collapse.

These features illustrate stages of coastal change rather than a set of permanent shapes. Weathering also weakens the rock in place, while waves remove material. Together, these processes help arches and stacks become unstable.

Chesil Beach and Studland: landscapes built from sediment

Chesil Beach is an approximately 18-mile-long shingle barrier beach, extending north-west from Portland towards West Bay. Its connection between the Isle of Portland and the mainland is described as a tombolo. The Fleet Lagoon, a shallow saltwater lagoon, lies behind much of the barrier, separating it from the mainland.

Unlike an arch, this landform consists of accumulated sediment rather than an opening eroded into bedrock. Longshore drift transports shingle along the coast, helping redistribute the material from which the beach is built.

Studland Bay has about four miles of sandy beaches, backed by sand dunes. Its sheltered beach and dune landscape provides another depositional contrast to Dorset's exposed rock features. The coast therefore contains both places where material is removed and places where sediment accumulates.

Upper Tees: V-shaped valleys, High Force and its gorge

Near its source, the Tees passes through upland terrain with steep slopes. Vertical erosion cuts down into the river bed. Rock fragments carried by the water abrade the bed, helping deepen the channel within the V-shaped valleys of the upper course.

The best-known named feature is High Force waterfall. Here, resistant dolerite, part of the Whin Sill, overlies softer limestone. The rocks do not erode equally: hydraulic action and abrasion remove the softer rock more rapidly, undercutting the resistant layer.

As the undercut grows, an unsupported overhang develops and eventually collapses. Repeated undercutting and collapse move the waterfall upstream. The steep-sided gorge below High Force marks the route along which the waterfall has retreated.

The waterfall and gorge are connected landforms. The waterfall is the active drop in the river; the gorge records the retreat of that drop through the landscape.

Middle and lower Tees: meanders, floodplains and levees

As tributaries join the Tees, its channel becomes wider and deeper. Around Barnard Castle, meanders and floodplains illustrate the growing importance of sideways, or lateral, erosion rather than downward cutting alone.

A meander is a bend in the river. Erosion on the outside of a bend and deposition on the inside shift the channel sideways. Over time, this movement helps widen the valley floor. During floods, water spreads beyond the channel and deposits sediment across the surrounding floodplain.

Further downstream, around Darlington and Yarm, the Tees has larger meanders and a wider floodplain. Continued erosion can narrow a meander's neck; if the river cuts through it and deposition seals the abandoned bend, an ox-bow lake can form. This is a possible development of a meander, not a claim that every Tees bend has become an ox-bow lake.

The lower Tees also has natural levees. When floodwater spills over the banks, it loses speed and deposits sediment. Repeated floods build up raised banks beside the channel. These are depositional landforms, unlike the gorge cut by erosion upstream.

Finally, the river enters its estuary at Teesside, where freshwater meets the saltwater of the North Sea.

Connecting each landscape to its processes

Dorset's arches, coves and stacks show how waves remove rock, while its beaches show the accumulation and redistribution of sediment. Along the Tees, upper-course downward erosion produces deep valleys and the High Force gorge, while lateral erosion and deposition shape downstream meanders, floodplains and levees.

For each named feature, connect three things: where it is, what its shape is, and how the relevant processes produced that shape. This turns a list of places into an explanation of a distinctive landscape.

Dorset coast: location and landforms

Part of the 155 km Jurassic Coast, from Exmouth to Poole.

• Swanage and Studland bays: less resistant sandstone and clay retreat faster than the chalk headland of The Foreland.
• Lulworth Cove: breach in resistant limestone → erosion of softer clay behind → wide bay with a narrow entrance.
• Durdle Door: limestone crack enlarged into a cave and then an arch.
• Old Harry: chalk stack at The Foreland; Old Harry's Wife: stump left after further erosion and collapse.
• Chesil Beach: approximately 18 miles of shingle; connects Portland to the mainland as a tombolo. Fleet Lagoon lies behind much of the barrier.
• Studland Bay: sandy beaches backed by dunes; depositional landscape.

River Tees: location and downstream sequence

Cross Fell, Pennines → North Sea at Teesside; approximately 130 km long; basin approximately 1,800 km².

• Upper course: vertical erosion and abrasion deepen V-shaped valleys.
• High Force: resistant Whin Sill dolerite above softer limestone. Undercutting → overhang collapse → upstream retreat → gorge.
• Barnard Castle: meanders and floodplains; lateral erosion and deposition become important.
• Darlington and Yarm: larger meanders and wider floodplain.
• Lower-course levees: repeated floods deposit sediment beside the channel.
• Teesside estuary: river freshwater meets North Sea saltwater.

Essential distinctions

• Erosional: coves, arches, stacks, valleys and gorges.
• Depositional: beaches, tombolos and natural levees.
• Both erosion and deposition: meanders and floodplain development.
• A gorge records waterfall retreat; a stack records the isolation of rock from a headland.