Overview
This lecture provides a comprehensive overview of key topics needed for AQA Geography Paper One, covering natural hazards, ecosystems, climate change, and physical landscapes, along with specific case studies and essential terminology.
Natural Hazards
- A natural hazard is a natural event with social impact, such as damage or loss of life.
- Types: tectonic (earthquakes, volcanoes), atmospheric (hurricanes), geomorphological (floods, landslides), biological (forest fires).
- People may live in hazardous areas due to economic, social, or knowledge reasons.
- Human activities, especially CO2 emissions, increase the frequency and severity of hazards.
Plate Tectonics & Earthquakes
- Earth's crust consists of tectonic plates moving atop the mantle due to convection currents.
- Plate boundaries: constructive (move apart), destructive (move together), conservative (slide past).
- Destructive margins (oceanic meets continental) cause earthquakes and volcanoes; conservative margins cause earthquakes only.
- Primary effects: immediate impact on people/buildings; secondary effects: later impacts like landslides.
- Case studies: Chile (2010), Italy (2009), Nepal (2015)—primary/secondary effects, responses, and recovery strategies.
Managing Tectonic Hazards
- Mitigation: mapping risk areas, emergency planning, evacuation, education, and stockpiling supplies.
- Earthquake-resistant building design and drills can reduce risk.
- Volcanic eruptions are easier to predict than earthquakes using monitoring technology.
Weather Hazards & Climate
- Global atmospheric circulation causes different climatic zones and affects hazards like storms.
- Tropical storms need warm deep seas and specific conditions; they are named by region (hurricane, cyclone, typhoon).
- Storm structure: calm eye, high winds, and heavy rain.
- Climate change increases storm frequency/severity, sea levels, and extreme weather events.
- Case study: Typhoon Haiyan (2013)—effects, responses, and rebuilding.
Managing Weather Hazards
- Preparation: storm shelters, disaster kits, education, and family plans.
- Prediction: satellites, computers, warnings.
- UK experiences extreme weather: snow, droughts, floods, and storms; Somerset Levels floods (2013/14) as case study.
Climate Change
- Evidence: rising global temperatures, melting ice, rising sea levels.
- Causes: mainly human—greenhouse gas emissions from fossil fuels, agriculture, and deforestation.
- Effects: flooding, crop failure, habitat loss, health impacts, and species extinction.
- Mitigation: renewable energy, carbon capture, replanting trees, and international agreements.
- Adaptation: water management, crop changes, coastal defenses, and risk reduction strategies.
Ecosystems & Biomes
- Food webs: energy flows from producers (plants) to consumers; decomposers recycle nutrients.
- Factors affecting ecosystems: biotic (living) and abiotic (non-living) components.
- Main biomes: tropical rainforest, desert, grassland, temperate forest, polar, tundra.
Tropical Rainforests
- Hot, wet, little seasonal variation; layers: lower, middle, top canopy.
- Soils are infertile; nutrients cycle rapidly.
- Plant and animal adaptations for survival.
- Deforestation causes: farming, mining, logging, infrastructure, energy.
- Impacts: biodiversity loss, climate impacts, soil erosion, pollution, displacement.
- Management: conservation, ecotourism, selective logging, debt reduction, replanting.
Hot Deserts
- Located 30° N/S; extreme temperatures, sandy soils.
- Plant/animal adaptations: water storage, root types, dormancy, and physical defenses.
- Case studies: Thar Desert, Western US Desert—economic uses and challenges.
- Desertification: due to climate change and human activities; solutions include planting trees, using alternative fuels, and soil management.
Cold Environments
- Polar and tundra regions: low temperatures, poor soils, specialized plant/animal adaptations.
- Case studies: Svalbard, Alaska—economies based on extraction, tourism, fishing, challenges of remoteness, infrastructure, and environmental concerns.
- Protection: treaties, conservation, limiting development impacts.
Physical Landscapes in the UK
- Waves: constructive (build beaches, gentle), destructive (erode, steep).
- Weathering: mechanical, chemical, biological; leads to mass movement and cliff collapse.
- Erosion and transportation shape coastlines—features include beaches, dunes, spits, bars.
- Coastal management: hard (sea walls, groynes) and soft (beach nourishment, managed retreat).
- Rivers: long/cross profiles, processes (erosion, transportation, deposition).
- Flooding: factors (physical/human), hydrographs, flood management (hard/soft engineering).
- Case studies: Jubilee River, Banbury.
- Glacial landscapes: processes (plucking, abrasion, freeze-thaw), landforms (corrie, tarn, U-shaped valleys), and impacts (tourism, farming).
- Conflict arises between economic activities and conservation.
Key Terms & Definitions
- Natural Hazard — a natural event causing social impact.
- Tectonic Plate — rigid section of Earth's crust moving over mantle.
- Primary Effect — immediate consequence of a hazard.
- Secondary Effect — later or indirect impact of a hazard.
- Mitigation — reducing the severity or impact of hazards.
- Biotic — living elements of an ecosystem.
- Abiotic — non-living elements of an ecosystem.
- Desertification — land degradation turning productive land into desert.
- Biome — large scale global ecosystem (e.g., rainforest, desert).
- Hydrograph — graph showing river discharge over time after rainfall.
Action Items / Next Steps
- Review case studies relevant to your selected options.
- Practice drawing and labeling key diagrams (e.g., plate boundaries, hydrographs, food webs).
- Complete checklist and workbook questions provided by your teacher or revision guide.
- Review key term definitions and practice applying them to real examples.