Coastal Landscapes

Coastal Landscape Systems

Components of Coastal Landscape Systems

Coastal landscapes are dynamic systems with several interacting components. These components include inputs, processes, and outputs. Understanding how these elements interact is essential for analyzing coastal environments.

Inputs

Inputs are the elements that enter the coastal system and initiate change. They can be classified into three main categories: energy, material, and human activity.

  1. Energy Inputs:
    • Wave Energy: Waves are primary energy sources, driven by wind. The energy they transfer to the coast depends on wind speed, duration, and fetch (the distance over which the wind blows).
    • Tidal Energy: Tides, caused by the gravitational pull of the moon and sun, contribute to the coastal energy budget. They influence the extent of coastal processes.
    • Solar Energy: Solar radiation impacts evaporation rates, weather patterns, and ultimately, coastal processes.
  2. Material Inputs:
    • Sediment Supply: Sediments are brought to the coast by rivers (fluvial), waves (marine), and wind (aeolian). These materials are essential for various coastal processes.
    • Organic Matter: Organic materials from marine and terrestrial sources contribute to the coastal ecosystem, influencing biological processes and habitat formation.
  3. Human Activity:
    • Coastal Development: Urbanization, tourism, and infrastructure development introduce materials and alter natural processes.
    • Coastal Management: Activities such as beach nourishment, groyne construction, and sea defenses are significant inputs affecting coastal dynamics.

Processes

Processes within the coastal system are the actions that transform inputs into outputs. They include a range of physical, chemical, and biological activities:

  1. Erosion: The wearing away of land by wave action, currents, and tidal movements. Key processes include:
    • Hydraulic Action: The force of waves compresses air in cracks, causing rock to break apart.
    • Abrasion: Rocks and sediment carried by waves grind against the coastline, eroding surfaces.
    • Attrition: Rocks and pebbles collide and break into smaller, smoother pieces.
    • Solution: The dissolving of soluble materials in seawater.
  2. Transportation: The movement of sediments along the coast by waves, currents, and tides. This includes:
    • Longshore Drift: The zigzag movement of sediment along the shore, driven by wave action at an angle.
    • Traction, Saltation, Suspension, and Solution: Different methods of sediment transport depending on particle size and energy levels.
  3. Deposition: The laying down of sediment when the energy of transporting forces decreases. This forms features like beaches, spits, and bars.
  4. Weathering: The breakdown of rocks in situ by physical (freeze-thaw), chemical (acid rain), and biological (root growth) processes.
  5. Biological Processes: Activities of plants and animals that influence coastal landscapes, such as the formation of coral reefs and mangroves.

Outputs

Outputs are the end products that leave the coastal system, resulting from the interaction of inputs and processes. They include:

  1. Sediment Loss: Sediments transported offshore or along the coast to different locations.
  2. Landform Changes: The creation or alteration of coastal features like cliffs, beaches, dunes, spits, and estuaries.
  3. Energy Dissipation: The reduction of wave energy through processes like breaking, refraction, and diffraction.