GCSE 9-1 Geography | Coasts | EVERYTHING you need

Summary

This video covers coastal landscapes in the UK, explaining how waves form and their impact on coastal erosion and deposition. It contrasts constructive waves, which build up beaches, with destructive waves that erode coastlines. Key processes like hydraulic power, abrasion, and longshore drift are detailed, leading to the formation of various coastal landforms such as cliffs, bays, and sand dunes. The video also discusses coastal defenses, highlighting hard engineering methods like seawalls and groins, alongside softer approaches like beach nourishment and dune regeneration. Overall, it provides a comprehensive overview of coastal dynamics and management.

Takeaways

• 🌊 Waves form when wind blows over the sea, creating ripples that develop into larger waves, with the fetch determining their power.
• 🏖️ Constructive waves have a strong swash that deposits sand and pebbles on beaches, typically forming during distant storms.
• 🌪️ Destructive waves are characterized by a stronger backwash that erodes sediment, commonly generated by local storms.
• 💧 Erosion occurs through various processes such as hydraulic power, abrasion, attrition, and corrosion, which weaken coastal structures.
• 🌿 Weathering can be chemical or mechanical, leading to the breakdown of rocks and cliffs, influencing coastal stability.
• 🏞️ Coastal landforms include cliffs, wave-cut platforms, headlands, bays, and erosional features like caves and stacks.
• 🏖️ Sandy beaches form in sheltered areas dominated by constructive waves, while pebble beaches are found in more exposed regions.
• 🏗️ Coastal defenses employ hard engineering methods like seawalls, groins, and rock armor, each with specific advantages and disadvantages.
• 🛡️ Soft engineering techniques, including beach nourishment and dune regeneration, help maintain coastal ecosystems while being more sustainable.
• 🌾 Dune regeneration involves planting marram grass and building protective fences to enhance dune stability and protect wildlife habitats.

Q & A

How do waves form?

Waves form when wind blows over the sea, creating friction with the water's surface, which causes ripples that grow into waves. The distance the wind blows across the water is known as the fetch.

What distinguishes constructive waves from destructive waves?

Constructive waves have a stronger swash than backwash, depositing sand and pebbles onto the beach, while destructive waves have a stronger backwash that erodes the beach and pulls sediment back into the sea.

What are the main types of coastal erosion processes?

The main types of coastal erosion processes include hydraulic power, abrasion, attrition, and corrosion. Hydraulic power occurs when waves compress air in cracks, abrasion involves rocks wearing down cliffs, attrition is when rocks collide and break apart, and corrosion involves weak acids dissolving rock.

What role does weathering play in coastal landscapes?

Weathering contributes to the breakdown of rocks along the coast, which can occur chemically or mechanically. Chemical weathering involves processes like carbonation and hydration, while mechanical weathering includes processes like freeze-thaw action.

What is longshore drift, and how does it affect beach sediment?

Longshore drift is the process by which sediment is transported along the coastline by waves hitting the shore at an angle. It causes pebbles and sand to be moved down the beach in a zigzag pattern.

What are some examples of erosional coastal landforms?

Erosional coastal landforms include cliffs, wave-cut platforms, headlands, and caves. For example, headlands form where hard rock is left standing after softer rock has been eroded away.

How do beaches and sand dunes form?

Beaches form in sheltered bays where constructive waves deposit sediment. Sand dunes form as sand accumulates and is stabilized by vegetation like marram grass.

What is the purpose of coastal defenses like seawalls and groins?

Coastal defenses like seawalls protect the shore from wave erosion, while groins trap sediment to help maintain beach levels and counteract longshore drift.

What are the advantages and disadvantages of using rock armor as a coastal defense?

Rock armor is effective in breaking waves and absorbing their energy, making it a relatively cheap and low-maintenance option. However, it can be expensive to transport, may disrupt local ecosystems, and some people find it unattractive.

What is beach nourishment, and what are its limitations?

Beach nourishment involves adding sand or shingle to widen or heighten a beach. While it is a cost-effective way to combat erosion, it requires constant maintenance to replenish the sediment due to natural processes like longshore drift.