🌍 Year 9 Geography

Coastal Processes & Landforms

Coastal Erosion Processes

• Hydraulic action: the force of waves hitting the cliff; air is forced into cracks, compresses, and blasts rock apart
• Abrasion (corrasion): sediment carried by waves is used like sandpaper to grind and scrape the cliff face
• Attrition: rocks and pebbles in the sea knock against each other, breaking into smaller, rounder fragments
• Solution (corrosion): slightly acidic seawater dissolves soluble minerals in rocks (e.g. calcium carbonate in limestone and chalk)

Coastal Transport

• Longshore drift: waves approach the beach at an angle (the angle of the prevailing wind). The swash carries sediment up the beach at that angle; the backwash returns it perpendicularly back down due to gravity. Net movement of sediment along the beach.
• Traction: rolling large boulders along the seabed
• Saltation: bouncing smaller pebbles along the seabed
• Suspension: fine sand and silt carried within the water
• Solution: dissolved minerals transported in the water

Erosional Landforms

• Headlands and bays: form where alternating bands of hard and soft rock meet the coast. Soft rock (clay, sand) is eroded quickly → bays. Hard rock (chalk, limestone) erodes slowly → headlands. The headland focuses wave energy → further erosion of the headland.
• Wave-cut platform: waves attack the cliff at the base, forming a wave-cut notch. The rock above collapses. The cliff retreats, leaving a flat rock platform at the base.
• Caves, arches, stacks, stumps: waves attack weaknesses (joints/faults) in a headland → cave forms. Wave attack from both sides → arch forms through the headland. The arch roof collapses → stack (isolated pillar). Stack erodes to sea level → stump. Old Harry Rocks (Dorset) is a classic example.

Depositional Landforms

• Beach: sediment deposited where wave energy is low (bays); may be sand (fine, sheltered) or shingle (exposed, coarser)
• Spit: longshore drift continues past a change in the direction of the coastline (e.g. a river mouth), depositing sediment as an elongated ridge. The end is often curved by secondary winds. e.g. Spurn Head (Humber estuary)
• Bar: a spit that grows all the way across a bay, cutting off a lagoon behind it
• Tombolo: a spit connecting the mainland to an island

Coastal Management

• Hard engineering: sea walls (concrete barriers — expensive, reflect waves increasing erosion of the beach below), groynes (wooden/rock barriers perpendicular to the beach — prevent longshore drift, build up beach), rock armour (large boulders — absorb wave energy), offshore breakwaters
• Soft engineering: beach nourishment (dredging sand from offshore and pumping it onto the beach — temporary, expensive, but more natural), dune stabilisation, cliff drainage
• Managed retreat: allowing low-value land to flood; compensate landowners; creates salt marshes which are important habitats and reduce wave energy naturally. Increasingly favoured by engineers as cost-effective long-term strategy.
• Holderness Coast (Yorkshire): fastest eroding coastline in Europe — up to 2m per year. Soft boulder clay easily eroded. Some areas protected (Mappleton), causing faster erosion elsewhere (Cowden).

Resource Management

Water Scarcity

• Physical water scarcity: not enough freshwater available (arid regions — Middle East, sub-Saharan Africa)
• Economic water scarcity: water exists but infrastructure or money to access it is lacking (parts of sub-Saharan Africa)
• Causes of water stress: population growth, economic development (more industry and agriculture), pollution reducing clean water supply, climate change altering rainfall patterns
• Virtual water: the water embedded in the production of goods — importing water-intensive products (e.g. cotton, beef) is effectively importing water
• Solutions: dams and reservoirs, desalination (expensive, energy-intensive), water transfer schemes (e.g. the South-North Water Transfer Project in China), grey water recycling, demand management (metering, pricing)

Food Security

• Food security: when all people at all times have access to sufficient, safe, nutritious food
• Approximately 800 million people are food insecure (2023)
• Causes: rapid population growth, poverty, climate change reducing agricultural productivity, land degradation, political instability and conflict, globalisation of food supply chains
• Food miles: the distance food travels from producer to consumer — raises environmental (carbon footprint) and sustainability concerns
• Intensive farming: high yields but environmental costs (fertiliser run-off, pesticide use, habitat loss)
• Sustainable approaches: agroforestry, crop rotation, permaculture, reducing food waste (up to one-third of food produced globally is wasted)

Energy

Energy Mix and Security

• Energy mix: the combination of different energy sources a country uses (fossil fuels, nuclear, renewables)
• Energy security: having reliable access to affordable energy. Countries reliant on energy imports are vulnerable.
• UK's changing energy mix: decline of coal (from 40% of electricity in 2012 to near zero by 2024), rise of wind and solar (renewables exceeded 50% of UK electricity generation in 2023)

Non-Renewable Energy Sources

• Fossil fuels (coal, oil, natural gas): energy-dense, reliable, established infrastructure. But finite, polluting (CO₂, NOₓ, SOₓ), contributing to climate change and geopolitically risky.
• Nuclear: low-carbon electricity, reliable baseload power. Issues: high capital cost, radioactive waste storage, public perception of risk, long construction times.

Renewable Energy Sources

• Solar: photovoltaic (PV) panels convert sunlight to electricity. Best in sunny climates. Cost has fallen dramatically (90% reduction 2010–2020). Variable output.
• Wind: onshore (cheaper) and offshore (stronger, more consistent winds; less visual impact). Intermittent.
• Hydroelectric power (HEP): dams generate electricity from water flow. Reliable, large-scale. Issues: flooding of valleys, impact on river ecosystems, displacement of communities (Three Gorges Dam, China).
• Tidal and wave: consistent in UK waters. Tidal barrages and lagoons; wave energy converters. Expensive and still in development.
• Geothermal: uses heat from the Earth's interior. Very reliable. Limited to volcanic/geothermal areas (Iceland, parts of the USA).
• Bioenergy: burning biomass (wood, crops, waste). Can be carbon-neutral if managed sustainably. Risk of land use change.

Population Dynamics

Demographic Transition Model (DTM)

• A model showing the relationship between birth rate, death rate, and population growth over time as a country develops
• Stage 1 (Pre-industrial): high birth rate, high death rate → slow population growth (most LICs historically)
• Stage 2 (Early industrial): high birth rate, falling death rate (improved medicine, sanitation, food) → rapid population growth (many LICs today)
• Stage 3 (Late industrial): falling birth rate (urbanisation, female education, contraception, children less economically valuable), death rate continues falling → slowing growth (MICs)
• Stage 4 (Post-industrial): low birth rate, low death rate → near-zero growth (most HICs)
• Stage 5: birth rate falls below death rate → population decline (some European countries, Japan)

Ageing Populations

• HICs face ageing populations: falling birth rates + increased life expectancy = growing proportion of elderly
• Challenges: pension costs, healthcare demand, working-age population too small to support retirees, labour shortages
• Responses: raising retirement age, immigration to supplement workforce, encouraging higher birth rates (tax incentives)
• Japan: most extreme case — world's oldest population (28% over 65), shrinking total population, labour shortages, government promoting robotics and immigration

Migration

• Push factors: war, poverty, environmental disaster, persecution, lack of opportunity
• Pull factors: safety, economic opportunities, family networks, better public services, political freedom
• Economic migrants: moving for economic reasons. Refugees: fleeing persecution or conflict — protected by the 1951 UN Refugee Convention.
• For source countries: brain drain (loss of skilled workers) vs remittances (money sent home — crucial for some LIC economies)
• For destination countries: economic benefits (filling labour gaps, entrepreneurship, cultural diversity) vs pressure on housing and services

Globalisation

What Is Globalisation?

• Globalisation: the increasing interconnection of the world's economies, cultures, and populations, driven by trade, investment, migration, and technology
• Accelerated by: improvements in transport (containerisation of shipping, cheap air freight), telecommunications (internet, mobile phones), trade liberalisation (free trade agreements, WTO), growth of TNCs

Transnational Corporations (TNCs)

• Companies that operate in multiple countries, with headquarters typically in an HIC and production in LICs/MICs
• Why locate production in LICs? Lower labour costs, weaker environmental regulations, tax incentives, access to raw materials
• Benefits for host countries: jobs, skills training, tax revenue, improved infrastructure
• Criticisms: exploitation of low wages, "race to the bottom" on workers' rights and environment, profits repatriated to the HIC parent rather than staying in the host economy, sweatshop conditions
• Example: Apple — designed in the USA, components from across Asia, assembled in China (Foxconn factories in Zhengzhou)

Winners and Losers from Globalisation

• Winners: TNCs (profits), consumers in HICs (cheaper goods), some LIC workers (jobs), skilled workers globally (opportunities)
• Losers: unskilled workers in HICs (jobs moved overseas), workers in poor conditions in LICs, the environment (increased production and transport), small local businesses outcompeted by global brands