Coasts Flashcards
(35 cards)
What are coastal landscape systems?
They are open systems with inputs (e.g., energy, sediment, water), processes (e.g., erosion, deposition), and outputs (e.g., sediment transfer, energy dissipation).
What are sediment cells?
Discrete areas of coastline where sediment movement is largely self-contained, often considered closed systems for management purposes. England and Wales have 11 sediment cells.
What is dynamic equilibrium in coastal systems?
A state where inputs and outputs of sediment and energy are balanced over time. Changes occur due to disruptions like storms or human intervention.
How do negative feedback loops operate in coastal systems?
Restores equilibrium (e.g., erosion forming an offshore bar).
How do positive feedback loops operate in coastal systems?
Amplifies change (e.g., dune erosion leads to further instability).
What are the key sources of energy in coastal systems?
Wind: Determines wave energy, fetch, and direction.
Waves: Formed by wind, with energy influenced by fetch and wind strength.
Tides: The gravitational pull of the moon and sun creates tidal ranges.
Currents: Flow of water transporting sediment and energy.
Geology: Lithology and structure influence wave action and energy dissipation.
What are the key processes shaping coastal landscapes?
Erosion: Hydraulic action, abrasion, attrition, and solution.
Transportation: Traction, saltation, suspension, and solution.
Deposition: Occurs when wave energy decreases, depositing sediment.
Weathering: Breakdown of rocks (mechanical, chemical, biological).
Mass Movement: Downslope movement of material, including rockfalls, slumping.
What factors influence erosion rates?
1.Wave energy.
2.Rock type and structure (e.g., resistance, fractures).
3.Coastal orientation and fetch.
4.Presence of sediment to protect or abrade cliffs.
What are erosional landforms, and how do they form?
Headlands and Bays: Formed on discordant coastlines due to differential erosion.
Wave-Cut Platforms: Created as cliffs retreat.
Caves, Arches, Stacks, and Stumps: Erosion widens weaknesses in headlands, forming sequential features.
What are depositional landforms, and how do they form?
Beaches: Created by constructive waves depositing sediment.
Spits: Longshore drift deposits sediment beyond a headland.
Bars: Spits that extend across a bay, enclosing a lagoon.
Tombolos: Bars connecting islands to the mainland.
Salt Marshes: Formed in sheltered areas behind spits or estuaries.
How are coastal landforms interrelated?
Landforms within a sediment cell are interconnected. Changes in one (e.g., erosion of a cliff) can impact others (e.g., sediment supply to beaches).
What are the causes of sea level change?
Eustatic Change: Global sea level rise or fall due to ice melt or thermal expansion.
Isostatic Change: Local land movement due to tectonics or post-glacial rebound.
What are the effects of sea level change on coastal landscapes?
Rising sea levels create submergent landforms (e.g., rias, fjords).
Falling sea levels create emergent landforms (e.g., raised beaches, marine terraces).
How does human activity intentionally influence coastal landscapes?
Coastal management strategies such as groynes, sea walls, and beach nourishment alter sediment movement and landform development.
How does human activity unintentionally influence coastal landscapes?
Activities such as dredging, dam construction, and urban development disrupt sediment budgets, leading to increased erosion and coastal retreat.
What are the consequences of human activity on coastal systems?
Altered sediment supply, habitat loss, changes in deposition patterns, and increased vulnerability to flooding.
What are the main strategies for managing coasts?
Hard Engineering: Groynes, sea walls, and rock armour to control erosion.
Soft Engineering: Beach nourishment, dune regeneration, and managed realignment to work with natural processes.
What are Shoreline Management Plans (SMPs)?
Strategies for managing risks within sediment cells, with options including:
Hold the Line: Maintain current defenses.
Advance the Line: Build defenses further out to sea.
Managed Realignment: Allow controlled retreat.
Do Nothing: Let nature take its course.
What are the key features of the Flamborough Head to Saltburn coastline?
Features: Chalk cliffs, wave-cut platforms, caves, arches, and stacks.
Processes: High wave energy, hydraulic action, abrasion, and longshore drift.
Sediment Transport: Longshore drift moves material southward.
What are the key characteristics of the Nile Delta?
Processes: Deposition dominates due to low wave energy.
Human Impacts: Aswan High Dam reduces sediment supply, increasing erosion and coastal retreat.
How is Sandbanks managed?
Groynes and beach nourishment protect high-value properties and maintain beaches for tourism.
What is the impact of sand mining at Pakiri Bay?
Coastal retreat, disruption to sediment cells, and increased erosion.
What are the advantages and disadvantages of hard engineering?
Advantages: Immediate and effective protection.
Disadvantages: Expensive, environmentally intrusive, and unsustainable long-term.
What are the advantages and disadvantages of soft engineering?
Advantages: Works with natural processes, sustainable.
Disadvantages: Requires maintenance, less effective in high-energy areas.
