Coastal Systems and Landscapes
ESSENTIAL OVERVIEW
“Coastal landscapes are dynamic systems shaped by the interaction of energy inputs, material transfers, and geomorphological processes.
This topic examines the coastal system as a set of interconnected components; inputs, throughputs, and outputs; where equilibrium is maintained through feedback mechanisms.
It covers the formation of distinct landforms resulting from erosion, deposition, and sea-level change, while also addressing the human management of these high-energy environments in the face of climate change.”
CRUCIAL KEYWORDS
Longshore Drift
The process by which sediment is moved along a coastline in a zig-zag manner due to waves approaching the shore at an oblique angle.
Eustatic Change
A global change in sea level caused by a rise or fall in the actual volume of water in the ocean, often linked to climate change.
Isostatic Change
A local change in land level relative to the sea, caused by the crust rising or sinking due to the weight of ice or tectonic activity.
Sediment Cell
A distinct area of coastline within which the movement of coarse sediment is largely self-contained, usually bounded by headlands.
Infiltration
Landscapes created when rising sea levels flood existing coastal areas, resulting in features like rias, fjords, and dalmatian coasts.
Core Processes & Theories
1) Sediment Budgets
The balance between sediment added to and removed from a coastal system. A positive budget leads to accretion (beach growth), while a negative budget leads to erosion.
2) Negative Feedback
A process that acts to neutralise or counteract a change within the coastal system, pushing the environment back towards a state of equilibrium.
3) Constructive vs Destructive Waves
Constructive waves have a strong swash and weak backwash, depositing sediment. Destructive waves have a weak swash and strong backwash, removing sediment.
CASE STUDY EVIDENCE
- The Holderness Coast in Yorkshire is the fastest eroding coastline in Europe, retreating at an average rate of approximately 2 metres per year due to its soft boulder clay geology.
- In Odisha, India, the Integrated Coastal Zone Management (ICZM) project focuses on ‘soft’ engineering, such as planting mangroves to reduce cyclone impact and prevent coastal erosion.
- The 1953 North Sea Flood caused sea levels to rise by 5.6 metres above mean sea level in some areas, leading to the creation of the Thames Barrier.
EXAM ESSENTIALS
- In 20-mark essays, always categorise your factors into ‘human’ and ‘physical’ to demonstrate a balanced geographical argument.
- Use the term ‘Dynamic Equilibrium’ when discussing how coasts respond to change; it shows the examiner you understand the coastal system is always adjusting.
- When describing landforms like Spits or Tombolos, you must mention ‘fluvial’ (river) or ‘aeolian’ (wind) processes if they contribute to the sediment supply.