coastal environments

Wave action

Waves form when wind transfers energy to the sea surface.

Constructive waves

Low energy, strong swash, weak backwash; deposit sediment and build beaches.

Destructive waves

High energy, weak swash, strong backwash; remove sediment and cause erosion.

Erosion processes

Hydraulic action, abrasion, attrition, and solution are methods of erosion.

Transportation

Movement of material along the coast by waves, including traction, saltation, suspension, and solution.

Longshore drift

Waves approach the coast at an angle; swash moves sediment diagonally while backwash moves it straight down.

Deposition

Occurs when wave energy decreases, often in sheltered areas, leading to the formation of beaches and spits.

Weathering

Breakdown of rock in situ (no movement), including mechanical, chemical, and biological weathering.

Mass movement

Downhill movement due to gravity, including sliding and slumping, often triggered by wave erosion.

Geology

Type of rock affects erosion rates; hard rock is resistant, while soft rock erodes quickly.

Vegetation

Roots stabilize soil and reduce erosion by holding sediment in place.

People

Coastal defences can interrupt natural processes and increase erosion in other areas.

Sea-level change

Rising sea levels increase erosion and flooding risks due to climate change factors.

Headlands and bays

Form where bands of hard and soft rock alternate, with soft rock eroding faster to create bays.

Cliffs and wave-cut platforms

Cliffs erode at their base, causing wave-cut notches, leading to cliff collapses and retreat.

Cave → arch → stack → stump

Sequence of erosion where waves exploit headland cracks, resulting in formations from caves to stumps.

Beaches

Form from deposited sand/shingle, with shapes depending on wave type.

Spits

Form by longshore drift extending from land into the sea, curving due to changing wind directions.

Bars

Spits that extend across a bay, cutting off water and forming lagoons.

Coral reefs

Found in warm, shallow, clear waters; they are extremely biodiverse ecosystems.

Mangroves

Adapted trees found in tropical coastal areas that trap sediment and reduce erosion.

Sand dunes

Formed by wind depositing sand behind beaches, stabilised by vegetation, serving as coastal defence.

Salt marshes

Found in sheltered areas like estuaries; built up from deposited mud and support specialised plants.

Abiotic factors (Mangroves)

High salinity, waterlogged, low-oxygen soils, and regular tidal flooding affect mangrove ecosystems.

Biotic factors (Mangroves)

Mangrove trees have aerial roots and support diverse adapted species, forming complex food webs.

Industrialisation

Pollution from factories harms ecosystems, with oil spills particularly harmful to marine life.

Agriculture

Fertilizers cause eutrophication and land cleared for agriculture leads to habitat loss.

Tourism

Construction destroys natural environments, leading to increased waste and disturbance.

Deforestation

Removal of mangroves for timber or land increases erosion and flooding risk.

Coastal conflicts

Different groups have competing interests, and management decisions create winners and losers.

Example – Holderness Coast

Mappleton's protection with groynes traps sediment, causing faster erosion in nearby areas.

Causes of coastal flooding

Storm surges, tsunamis, and climate change contribute to rising sea levels and flooding risks.

Prediction of coastal flooding

Monitoring weather systems and sea levels and using early warning systems reduce risks.

Prevention of coastal flooding

Implementing sea defences, raised buildings, and public education to mitigate flooding.

Hard engineering

Structures like sea walls and groynes are effective but can cause environmental damage.

Soft engineering

Utilises more sustainable methods like beach nourishment and managed retreat, though requires maintenance.

Shoreline Management Plans

Long-term strategies for coastlines that decide on interventions, including hold the line, managed retreat, or no intervention.

Erosional and depositional processes

Erosional processes remove material from coasts, forming landforms like headlands and bays, while depositional processes accumulate sediment, leading to features such as beaches, spits, and bars.

Distinctive ecosystems

Coastal ecosystems include coral reefs, mangroves, sand dunes, and salt marshes, each with unique characteristics and ecological roles in coastal environments.

Abiotic and biotic characteristics

Abiotic factors are non-living components like salinity and temperature, while biotic factors include plant and animal life. Both influence the dynamics and health of coastal ecosystems.

Impact of human activities

Human activities such as industrialisation, agriculture, tourism, and deforestation threaten coastal ecosystems by causing pollution, habitat loss, and increased erosion.

Case studies of coastal management

Analyzing case studies from developed and developing countries reveals diverse approaches to coastal management challenges, highlighting varying resources and methodologies.

Conflicts in coastal management

Conflicts arise among stakeholders with differing priorities, such as economic development versus environmental conservation, necessitating balanced coastal management approaches.

Causes of coastal flooding

Coastal flooding may result from storm surges, tsunamis, and rising sea levels due to climate change, making it crucial to understand these risks for effective management.

Prediction and prevention of flooding

Predicting coastal flooding involves monitoring weather and sea levels, while prevention focuses on effective urban planning and public education to enhance community resilience.

Coastal management strategies

Strategies include hard engineering methods like seawalls and soft engineering methods such as beach replenishment, aimed at sustainable management of coastal environments.