Why do natural hazards happen where they do, and how can their impact be reduced?
The causes of selected environmental hazards (earthquakes, volcanoes and tropical storms), their effects on people and the environment, and the strategies used to predict, prepare for and respond to them, with their limitations.
An SQA Higher Geography answer on the Environmental Hazards global issue, covering the causes of earthquakes, volcanoes and tropical storms, their social, economic and environmental effects, and the prediction, preparation and response strategies used to manage them, with named examples and their limitations.
Reviewed by: AI editorial process; not yet individually human-reviewed
Have a quick question? Jump to the Q&A page
Jump to a section
What this key area is asking
Environmental Hazards is one of the six Global Issues options in SQA Higher Geography, and a centre may choose it as one of its two studied issues. The SQA wants you to explain the causes of selected hazards (the spec centres on earthquakes, volcanoes and tropical storms), describe their effects on people and the environment, and assess the strategies used to manage them. The key idea running through the topic is that the impact of a hazard depends not just on its physical strength but on how developed and prepared the place it strikes is, so the same magnitude event can be a disaster in one country and a manageable shock in another.
The causes of hazards
Earthquakes happen where plates lock together under friction, stress builds, and the sudden release of that stress shakes the ground. The point underground where it starts is the focus; the point directly above on the surface is the epicentre. They occur at destructive boundaries (where one plate is subducted), at conservative boundaries (where plates slide past, as at the San Andreas Fault), and along faults near constructive boundaries.
Volcanoes form where magma reaches the surface. At a destructive boundary the subducted plate melts and the gas-rich magma rises and erupts violently. At a constructive boundary plates move apart and runny lava rises gently into the gap, building new crust, as in Iceland on the Mid-Atlantic Ridge. Hot spots such as Hawaii produce volcanoes away from boundaries, where a plume of heat rises through the plate.
Tropical storms (hurricanes, cyclones, typhoons) form over oceans warmer than about . Warm, moist air rises rapidly, and as the water vapour condenses it releases latent heat, which powers the storm, while the Earth's rotation spins it. They need a deep layer of warm water and a position a few degrees from the Equator, which is why they strike particular coasts in particular seasons.
The effects of hazards
The scale of these effects depends heavily on development. A wealthy country with strong buildings, warning systems and emergency services suffers far fewer deaths than a poor country where buildings are weak, warnings do not reach people, and there is little money to respond and rebuild.
Managing hazards
Prediction works well for tropical storms, which can be tracked by satellite for days, giving time to evacuate; it is moderate for volcanoes (monitoring tremors, gas and bulging ground) but weak for earthquakes, which cannot be reliably timed. Preparation includes aseismic (earthquake-resistant) building design, cyclone shelters and sea walls, land-use planning that keeps people off the worst ground, and public education and drills. Response covers search and rescue, emergency aid, temporary shelter and the longer rebuilding effort, including early-warning systems that buy seconds or minutes.
Examples in context
Example 1. Contrasting earthquakes. A large earthquake striking a well-prepared, high-income area with strict building codes and drills typically causes far fewer deaths than a smaller earthquake in a low-income area of poorly built housing and weak emergency services. The contrast is the classic Higher example of why development, not magnitude alone, decides the death toll, and why preparation (building design and planning) is the most effective management strategy for a hazard that cannot be predicted.
Example 2. A tropical storm. A tracked tropical storm gives days of satellite warning, so mass evacuation and cyclone shelters can save lives even in a developing country, as Bangladesh's improved warning and shelter network has shown over successive cyclones. This illustrates that where prediction is reliable, preparation and response together can sharply cut deaths, even where wealth is limited.
Try this
Q1. Explain the formation of a tropical storm. [4 marks]
- Cue. Warm ocean over ; rapid rising of warm, moist air; condensation releases latent heat that powers the storm; the Earth's rotation spins it; it forms a few degrees from the Equator and needs a deep warm layer.
Q2. Describe the social and economic effects of a named environmental hazard. [5 marks]
- Cue. Social: deaths, injuries, homelessness, disease from broken water and sanitation. Economic: destroyed homes, roads and businesses, lost income and jobs, the cost of aid and rebuilding, and lost tourism or trade.
Exam-style practice questions
Practice questions written in the style of SQA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
SQA Higher style6 marksExplain the causes of earthquakes and volcanoes with reference to plate tectonics.Show worked answer →
Worth 6 marks, so develop the plate-boundary processes rather than just naming boundaries. Split it roughly evenly between earthquakes and volcanoes.
Earthquakes (about 3 marks). The Earth's crust is broken into plates that move on the mantle, driven by convection currents. At a destructive (convergent) boundary an oceanic plate is forced beneath a continental one (subduction); the plates lock together under friction, stress builds, and when it is suddenly released the ground shakes - an earthquake, whose origin is the focus and whose surface point is the epicentre. At a conservative boundary, such as the San Andreas Fault, plates slide past each other and stick, then jerk free, again releasing energy as an earthquake.
Volcanoes (about 3 marks). At a destructive boundary the subducted plate melts in the heat of the mantle, and the molten rock (magma), being less dense, rises through cracks and erupts as a volcano, often violently because the magma is thick and gas-rich. At a constructive (divergent) boundary plates move apart, magma rises into the gap, and gentler eruptions of runny lava build new crust, as along the Mid-Atlantic Ridge in Iceland. Hot spots, such as Hawaii, produce volcanoes away from plate boundaries.
SQA Higher style8 marksFor a named environmental hazard, evaluate the effectiveness of strategies used to manage its impact.Show worked answer →
Worth 8 marks. Choose one hazard and one or two named events, give strategies under prediction, preparation and response, comment on how well each works, and reach a judgement. Use earthquakes here.
Strategies and their effectiveness (about 6 marks). Prediction is weak for earthquakes: seismographs, gas and groundwater monitoring and historical records can map risk but cannot give a reliable warning of the exact time, so prediction saves few lives directly. Preparation is far more effective: aseismic (earthquake-resistant) building design with deep foundations, cross-bracing and counterweights keeps buildings standing, and Japan's strict building codes and drills meant a large quake there caused far fewer deaths than a similar-magnitude quake in Haiti, where buildings were poorly built. Land-use planning keeps the most vulnerable buildings off the worst ground. Response - trained search-and-rescue teams, stockpiled aid, and earthquake early-warning systems that give seconds of alert to stop trains and surgeries - reduces deaths after the event but depends on a country being able to afford it.
Judgement (about 2 marks). Preparation, especially building design and planning in advance, is the most effective strategy, because the hazard cannot be stopped or reliably predicted. The gap in deaths between rich and poor countries shows that effectiveness depends as much on a country's wealth and governance as on the technology itself.
Related dot points
- The physical and human causes of climate change, the local and global effects, and the management strategies and their limitations.
An SQA Higher Geography answer on climate change, covering the physical and human causes including the enhanced greenhouse effect, the local and global effects on people and environments, and the management strategies from international agreements to renewable energy, with their limitations.
- The characteristics of a selected natural region (climate, soils, vegetation and wildlife), the human use of that region, the conflicts and changes that result, and the strategies used to manage them sustainably.
An SQA Higher Geography answer on the Natural Regions global issue, covering the climate, soils, vegetation and wildlife of a selected natural region such as the tropical rainforest, how people use and change it, the conflicts that result, and the management and sustainability strategies, with named examples.
- Indicators of development and their validity, the reasons for differences in development between and within countries, and a study of a disease including its causes, impact, management and strategies.
An SQA Higher Geography answer on development and health, covering social, economic and composite indicators of development and their validity, the reasons for development differences between and within countries, and a case study of a disease such as malaria including its spread, impact and management.
- The processes of glacial erosion and deposition and the resulting upland landforms, and the processes of coastal erosion and deposition and the resulting features of erosion and deposition.
An SQA Higher Geography answer on the lithosphere, covering the processes of glacial erosion and deposition and landforms such as corries, aretes and U-shaped valleys, and the processes of coastal erosion and deposition that create headlands, stacks, beaches and spits, with Scottish examples from the Cairngorms.
- The need for management of recent urban change in a developed-world city such as Glasgow and in a developing-world city, including housing, transport and the environment.
An SQA Higher Geography answer on urban change, covering the need to manage recent change in a developed-world city such as Glasgow and a developing-world city such as Mumbai, including problems and solutions in housing, transport and the urban environment, and the growth of shanty towns.
Sources & how we know this
- SQA Higher Geography Course Specification — SQA (2018)