Holderness Coast Case Study - AQA A-Level Geography

Summary

The transcript focuses on a presentation about the Hardest Coast, specifically the local case study of Flamborough Head, addressing various hazards including coastal erosion, flooding, and the impact of human activity. The geology of the area, including resistant chalk formations and erosion features like caves and stacks, is discussed. Coastal erosion, retreat, and rising sea levels are major concerns, with solutions like managed retreat and defense strategies, such as groins and seawalls. The impact on local communities and ecosystems, including Spurn Head and the Humber Estuary, is also covered, emphasizing the need for sustainable approaches to coastal defense and erosion management.

Takeaways

• 😀 The Hardest Coast case study focuses on coastal erosion and flooding issues, particularly in the context of AQA A-level geography.
• 😀 Flamborough Head has resistant chalk, creating features like headlands, caves, arches, and wave-cut platforms, while softer boulder clay is more vulnerable to erosion.
• 😀 The coastline experiences significant erosion due to longshore drift, moving material southward and forming features like the Spurn Point spit.
• 😀 The Hardest Coast is retreating at a rate of 1.8 meters per year, with significant coastal erosion due to the erosion of soft clay and lack of natural sediment deposition.
• 😀 Over 200 homes are at risk of being lost to coastal erosion in the next 20 years, and nearly 7,000 properties are at risk of being lost in the next century if no action is taken.
• 😀 Human interventions such as groins and seawalls have been implemented, but they have limited success, and erosion continues in some areas.
• 😀 The Humber Estuary is particularly vulnerable to coastal flooding, with rising sea levels threatening approximately half a million people living below 2 meters above sea level.
• 😀 Managed retreat has been considered in areas like Sunk Island to address coastal erosion, with selective breaching of salt marsh embankments as part of this strategy.
• 😀 Spurn Point, a fragile recurved spit, is growing at approximately 10 cm per year but is threatened by winter storms and erosion despite coastal defenses.
• 😀 The economic viability of coastal defense projects, such as the £6.3 million investment in Mapleton, is questionable, especially if property values continue to decline due to ongoing erosion.

Q & A

What is the significance of Flamborough Head in the context of coastal hazards?

Flamborough Head is significant due to its resistant chalk geology, which forms features like headlands, caves, arches, stacks, and wave-cut platforms. These features are a result of coastal erosion, making it an important case study for studying the effects of erosion on coastlines.

What is the rate of coastal erosion along the Hardest Coast?

The Hardest Coast is retreating at an average rate of 1.8 meters per year. This rate of erosion is accelerated by the presence of soft materials like boulder clay, which are easily eroded by waves.

What is longshore drift, and how does it impact coastal features like Spurn Point?

Longshore drift is the process by which material is transported along the coast by the waves. It impacts coastal features like Spurn Point, where material eroded from other areas is carried down the coast and deposited, forming a spit. This process contributes to the growth of features like Spurn Point.

How much sediment is carried southward along the Hardest Coast each year?

Approximately half a million tons of sediment are carried southward each year along the Hardest Coast in suspension due to the process of longshore drift.

What are the potential consequences of not addressing coastal erosion along the Hardest Coast?

If no action is taken, more than 200 homes are at risk of being lost to coastal erosion within the next 20 years. Additionally, nearly 7,000 properties worth over a billion dollars are predicted to be affected by coastal erosion in this century.

What are some of the environmental benefits of features like Spurn Point?

Spurn Point is a large, fragile spit that is crucial for biodiversity. It forms wetlands, which are important for birdlife and overall environmental health, supporting ecosystems like salt marshes and sand dunes.

What is managed retreat, and how has it been applied at the Hardest Coast?

Managed retreat is a strategy where coastal defenses are removed or allowed to deteriorate in order to let natural processes take their course. At the Hardest Coast, this has been applied in places like Sunk Island, where embankments were selectively breached to reverse increases in erosion and salt marsh degradation.

What role do human activities play in accelerating coastal erosion at the Hardest Coast?

Human activities such as building caravan parks and interfering with natural processes like longshore drift contribute to accelerating coastal erosion. Unsuitable defense strategies, such as the use of groins, can also have adverse effects, leading to further erosion in other areas.

What defense measures have been implemented at Mapleton to address coastal erosion?

At Mapleton, a defense scheme was introduced in 1991, costing £2.1 million. This included the construction of two rock groins and rock armor (revetments) to prevent erosion of the cliffs. The scheme also involved beach nourishment to encourage deposition and reduce the rate of erosion.

What were the challenges faced by the coastal defenses at Spurn Head in 2013?

In 2013, the coastal defenses at Spurn Head, which had been originally constructed by the military, were unable to cope with the largest tidal surge in 60 years. This led to the destruction of groins, the collapse of defenses, and the loss of access to roads, highlighting the challenges of maintaining effective coastal defenses.