National Year 10 Geography
Chapters: 3
1. 3.1.1 The challenge of natural hazards
Natural hazards · Tectonic hazards · Weather hazards · Climate change
- Natural Hazards – A natural hazard is a natural event that can harm people and property, such as an earthquake, volcano, landslide, flood, drought or cyclone. It becomes a disaster when it hits people who are not ready. Geological hazards come from inside the Earth; meteorological (weather) hazards come from the air and water. Risk = hazard × vulnerability ÷ capacity to cope, so warning systems, strong buildings and trained people cut the damage.
- Distribution of Oceans and Continents: Drift, Spreading and Plates – In 1912 Alfred Wegener said all continents were once one landmass, Pangaea, surrounded by one ocean, Panthalassa, and that they drifted apart. Matching coastlines, rocks, fossils, glacier deposits and placer gold supported him, but he could not explain the force. Mapping the ocean floor showed ridges, plains and trenches; Harry Hess then proposed sea-floor spreading: new crust forms at mid-ocean ridges and old crust sinks at trenches. This led to plate tectonics: the lithosphere is broken into rigid plates that move on the soft asthenosphere and meet at divergent, convergent and transform boundaries. The Indian plate broke away from the south, moved north, and collided with Asia to raise the Himalayas.
- Weather and Climate: From the Atmosphere to the Monsoon – The atmosphere is a blanket of air around the Earth: 78% nitrogen, 21% oxygen and 1% other gases. It has five layers; all weather happens in the lowest, the troposphere. Weather is the state of the air on one day: temperature, pressure, wind, humidity, clouds and rain. Climate is the average weather of 30 years or more. India has four seasons, and the monsoon winds bring most of its rain. Burning fuels adds carbon dioxide, which warms the Earth and brings more floods and heatwaves. Our carbon footprint is how much of this gas our life adds.
- Climate Change and the Greenhouse Effect – Climate is the average weather of a place over about 30 years. Greenhouse gases like carbon dioxide and methane trap some of the heat the Earth gives off. Humans have added a lot more of these gases by burning fossil fuels and cutting forests, so the Earth is warming. This causes melting ice, rising seas and more extreme weather. We can cut emissions (mitigation) and prepare for changes (adaptation).
2. 3.1.2 The living world
Ecosystems · Tropical rainforests · Hot deserts (option: hot deserts OR cold environments) · Cold environments (option: hot deserts OR cold environments)
- Tropical Rainforests: Life in the Hot, Wet Forest – Tropical rainforests grow near the equator where it is hot (about 27 °C) and very wet (over 2,000 mm of rain a year) all year. The forest has layers: emergent, canopy, under-canopy and shrub layer, and forest floor. Plants adapt with buttress roots, drip-tip leaves, lianas and epiphytes; animals adapt with camouflage, climbing and special diets. Nutrients cycle fast, so the soil is thin and poor. Deforestation for farming, cattle, logging, mining and roads causes soil erosion, loss of biodiversity, climate change and harm to local people. Sustainable management (selective logging, replanting, agroforestry, ecotourism, protected areas, international agreements) uses the forest without destroying it.
- Hot Deserts: Climate, Life, People and Desertification – Hot deserts are places that get less than about 250 mm of rain a year and are hot for most of the year. They lie mostly in two belts around 15–30° north and south of the equator, where dry air sinks from high up. Other causes of dryness are cold ocean currents, rain shadows behind mountains and great distance from the sea. With no clouds, days are very hot (often over 40 °C) and nights can be cold, so the daily range is large. The aridity index (P ÷ PET) tells how dry a place is: below 0.2 is arid. Soils are thin, sandy or stony and low in humus. Plants survive by storing water, having spines and wax, and deep or wide roots; animals by being active at night, burrowing and saving water. Deserts offer solar energy, minerals, farming with irrigation and tourism, but bring heat, water shortage, remoteness and flash floods. Desertification is good land turning into desert, caused by drought and climate change plus overgrazing, cutting trees, over-farming and population growth. It can be slowed by planting trees, careful grazing, water harvesting and new technology.
- Polar Regions: The Arctic and Antarctica – The polar regions lie around the North and South Poles, roughly inside the Arctic and Antarctic Circles (66.5°). The Arctic is a frozen ocean ringed by land; Antarctica is a continent buried under an ice sheet up to about 4 km thick. They are cold because sunlight arrives at a low angle and spreads out, and because white ice reflects most of it. The 23.5° tilt of Earth's axis gives months of daylight (midnight sun) and months of darkness (polar night). Plants are few; animals such as polar bears (Arctic) and penguins (Antarctica) are adapted with fat, fur and feathers. Indigenous peoples like the Inuit and Sami live in the Arctic; Antarctica has only scientists. Ice cores record past climate. The poles are warming fast; melting sea ice speeds warming (albedo feedback) and melting land ice raises sea level. The Antarctic Treaty keeps Antarctica for peace and science, while Arctic sea routes and resources raise new questions of cooperation.
3. 3.1.3 Physical landscapes in the UK (study two of coasts, rivers, glacial)
UK physical landscapes · Coastal landscapes in the UK (option) · River landscapes in the UK (option) · Glacial landscapes in the UK (option)
- UK Physical Landscapes: Uplands, Lowlands and River Systems – The physical landscape of the UK is a tilted island: high uplands in the north and west, low lowlands in the south and east. Uplands are land mostly over 600 m: the Scottish Highlands (Ben Nevis 1,345 m, the highest point), the Southern Uplands, the Lake District, the Pennines (the backbone of England), Snowdonia and the mountains of Wales, and the Mourne Mountains. Lowlands are mostly under 200 m: the Fens, East Anglia, the London Basin and the chalk downs. The reason is geology: the north-west is built of old, hard igneous and metamorphic rocks that resist erosion; the south-east of younger, softer sedimentary rocks such as clay, sand and chalk. Past plate movements and volcanoes lifted the north-west, and ice ages carved upland valleys and dropped clay on the lowlands. Most rivers rise in the wet western uplands and flow to the sea through lowlands: the Severn (longest), Thames, Trent, Tay, Tyne and others. Relief affects climate (wetter, cooler uplands) and land use: sheep, forestry, reservoirs and national parks in the uplands; arable farming and big cities in the lowlands.
- Coastal Landscapes: How the Sea Shapes the Land – A coast is where land meets sea. It works as a system: energy from waves, tides, currents and wind moves sediment between stores such as cliffs, beaches and the sea bed, and each stretch of coast is a sediment cell. Waves form when wind blows over the sea; the fetch controls their size. Constructive waves build beaches; destructive waves remove them. High-energy coasts have big waves and cliffs; low-energy coasts have small waves, beaches and marshes. Weathering (freeze-thaw, salt, chemical) and mass movement (rockfall, landslide, slumping) weaken cliffs. The sea erodes by hydraulic action, abrasion, attrition and solution, transports by traction, saltation, suspension, solution and longshore drift, and deposits where energy drops. Erosion makes headlands and bays, wave-cut notches and platforms, and caves, arches, stacks and stumps. Deposition makes beaches, spits, bars, tombolos, sand dunes, mudflats and saltmarsh, especially in estuaries. Sea level changes (eustatic, isostatic, tectonic) create emergent coasts (raised beaches) and submergent coasts (rias, fjords). Climate change raises sea level and storminess. Coasts are managed by hard engineering, soft engineering, managed retreat, shoreline management plans and integrated coastal zone management.
- Rivers: From Source to Sea – A river is fresh water flowing in a channel from high land (the source) to a sea, lake or bigger river (the mouth). On the way it erodes, transports and deposits rock. The upper course is steep, with V-shaped valleys and waterfalls. The middle course has meanders. The lower course is flat, with floodplains, levees and deltas. Heavy rain can make a river flood; we manage floods with hard (dams, levees) and soft (trees, floodplain zoning) methods. Lakes store water; rivers flow into and out of them.
- Glacial Landscapes: How Ice Shapes Mountains and Valleys – A glacier is a slow river of ice. It works as a system: snow is added at the top (accumulation) and ice is lost at the bottom (ablation). The balance decides whether the snout advances or retreats. Ice erodes rock by freeze-thaw, plucking and abrasion. This makes corries, arêtes, pyramidal peaks, U-shaped troughs, hanging valleys and ribbon lakes. When ice melts it drops till, building moraines, drumlins and erratics; meltwater builds outwash plains, eskers and kames. Next to the ice, frozen ground makes periglacial features such as pingos and patterned ground. People farm, live and holiday in these uplands, and must manage tourism and climate change.