Coastal Landscapes as Systems

This section introduces the concept of coastal systems in Geography. It explains how coastal landscapes can be viewed as open systems with various inputs, outputs, and processes.

Coastal systems are characterized as open systems, allowing energy transfer between neighboring cells. The key components of these systems include:

Definition: Open systems in coastal landscapes allow energy transfer between neighboring cells, creating a dynamic environment.

Inputs:

• Kinetic energy from wind and waves
• Thermal energy from the sun
• Potential energy from material on slopes

Outputs:

• Marine and wind erosion from beaches and rock surfaces
• Evaporation

Processes:

• Stores, including beach and nearshore sediment accumulation
• Flows, such as longshore drift

The concept of system feedback in coastal landscapes is introduced, highlighting the importance of equilibrium:

Highlight: When inputs and outputs are equal, the coastal system is in equilibrium. Any disturbance triggers self-regulation to restore balance, demonstrating negative feedback.

The section also covers sediment cells, which are crucial components of coastal systems:

• Stretches of coastline found nearshore
• Involve movement of sediment
• Can be closed systems with no sediment transfer between cells
• 11 large sediment cells exist around the coast of England and Wales

Example: The coastline of England and Wales is divided into 11 large sediment cells, each representing a distinct coastal system with its own sediment dynamics.

Wave Transformation in Shallow Water

This section examines how waves change as they approach the shore, a crucial process in understanding coastal systems and their impact on landforms.

Wave transformation stages:

1. Initial contact with shallow water:

   • Occurs when water depth is half the wave height
   • Deepest water molecules drag against the seafloor

2. Changes in wave characteristics:

   • Wave slows down due to friction with the seafloor
   • Wavelength decreases
   • Successive waves bunch up

3. Wave steepening:

   • Deepest part of the wave slows down
   • Wave crest advances ahead of the base

4. Wave breaking:

   • Occurs when water depth is less than 1.3 times the wave height
   • Significant forward movement of water and energy

5. Swash and backwash:

   • Swash: water moves up the shore after wave breaking
   • Backwash: water travels back down the beach due to gravity

Highlight: The process of wave transformation in shallow water is crucial for understanding erosion and deposition patterns in coastal systems.

The section includes a visual representation of wave motion and breaking patterns, illustrating the complex dynamics of coastal systems.