2B.1

The littoral zone (costal zone)

constantly changing due to dynamic interaction between processes operating in the sea, ocean, and on land.

stretches out to sea and onto the shore

The littoral zone is one of dynamic equilibrium, due to the wide range of natural processes interacting with it.

back-shore and the foreshore are where the greatest level of human activity occurs, and physical processes mostly occur.

factors that may influence this zone

Short term factors: individual waves, daily tides, and seasonal storms.

Long term factors: sea level change and climate change.

factors that cause coasts to vary

Geomorphic

Anthropogenic

infrastructure

people

rocktype

Energy of the coast

vegetation

prevailing winds

direction of longshore drift

Processes

inputs

out puts

click to edit

click to edit

Marine (waves, tides, storm surges)

Atmospheric (weather/climate, climate change, solar energy)

Land (rock type and structure, tectonic activity)

People (human activity, coastal management)

click to edit

Weathering (wearing away of material) Mechanical and physical weathering

Mass movement (movement of surface material)

Erosion (wearing away of material)

Transport (movement of sediment)

Deposition (dropping off of sediment)

Erosional landforms (arch, stack, stump, headland, bay)

Depositional landforms (splits, tombolos, beaches)

Different types of coasts (rocky shores, sandy beaches, coastal wetlands, coral reefs)

Dynamic equilibrium
(A state of balance between continuing processes.)


factors which may affect t this

Waves

Dredging

Tides

Climate change

Valentine’s Classification of coasts

Sections of coast can be classified into different types using a variety of criteria, such as geology, sea-level rise and fall, and land-level rise and fall, which cause long-term changes, and erosion and deposition, which cause short-term changes.

Isostatic Land Change

change is a change in local land level.

Rises in local land level causes a fall in local sea level.

click to edit

This may be due to:

Post-glacial adjustment

Accretion

Sink regions in the sediment cell are experiencing net deposition, land is built up, leading to a fall in sea level.

Eustatic Land Change

click to edit

This includes the effects of both naturally and anthropogenically driven climate change:

Warmer atmosphere

Warmer oceans

Ice caps melt

Increases volume of water in sea

SL increases globally (eustatic SLR)

High and low energy coastlines

Low Energy coasts

Constructive waves

Hige enegy coast

Depositional and Transport

Form beaches, spits, salt marshes and sand dunes

located on low land coasts or on costal plain landscapes

Eg: Mediterranean coasts, East Anglian coasts

Sediments from eroded land

Form cliffs, wave cut platforms, sea caves, arches, stacks

Destructive waves

Located on rocky landscapes and on both highland and low land coasts

Eg: Atlantic coasts of Norway and Scotland