Coastal Landscape Overview

Overview

This lecture covers key terminology, processes, landforms, and management strategies relating to coastal landscapes in A-Level Geography.

Backshore: area between high watermark and landward limit.
Foreshore: area between high and low watermarks.
Inshore: between low watermark and the point where waves no longer affect the seabed.
Offshore: beyond the influence of waves on the seabed.

The coast is a system with inputs (wind, waves, tides, currents), flows (movement of material), and stores (energy/matter held).
Wave movement: friction with seabed slows waves, swash moves water up the beach, backwash returns it to sea.

Constructive waves: low height, low frequency, strong swash, weak backwash (build beaches).
Destructive waves: high height, high frequency, strong backwash (erode beaches).
Wave refraction: waves bend towards shallower water, increasing erosion on headlands and deposition in bays.
Longshore drift: movement of sediment along the coast due to angled wave approach.
Rip currents: strong currents moving away from the shoreline.

Tide: periodic rise and fall of sea level (spring tide after new/full moon; neap tide after first/third quarter).
Tidal range: difference between high and low tides.
High energy coastlines: high wave energy, more erosion, headlands, cliffs.
Low energy coastlines: low wave energy, more deposition, beaches, spits.

Marine processes: erosion, transportation, deposition.
Sub-aerial processes: weathering, mass movement.
Landforms: caves, arches, stacks, stumps, wave-cut notches/platforms, runnels, cusps, spits, bars, mudflats, salt marshes.
Spits: simple (straight), compound (curved).
Bars: ridge of sand shingle joining headlands, may form lagoons.
Mudflats: develop into salt marshes under suitable conditions.

Eustatic change: due to water volume/ocean basin shape (global).
Isostatic change: due to land movement (local).
Submergent coastlines: formed by sea level rise (rias, fjords, Dalmatian coasts).
Emergent coastlines: formed by sea level fall (raised beaches, marine platforms, relict cliffs).

Aims: prevent flooding, coastal erosion, stabilize beaches, protect habitats.
Shoreline Management Plans (SMP): four options—hold the line, managed realignment, no active intervention, advance the line.
Drawbacks: time-consuming, costly, sometimes unpopular or unsustainable.
Integrated Coastal Zone Management (ICZM): considers environment, economy, and stakeholders at all scales.

Pevensey Bay: uses beach recharge, recycling, groyne bypassing, and ongoing review; involves multiple stakeholders.
Sundarbans: risks from natural hazards and human activity; responses include resilience, mitigation, and adaptation strategies.

Backshore — area above high tide affected only during storms.
Foreshore — area between high and low tide.
Longshore Drift — transport of sediment along the coast by waves.
Rip Current — strong, narrow current moving seaward.
Eustatic Change — global sea level change from water volume.
Isostatic Change — local sea level change from land movement.
Shoreline Management Plan (SMP) — local plan for managing a coast.
Integrated Coastal Zone Management (ICZM) — holistic strategy involving multiple stakeholders.