2025 Cambridge IGCSE Geography (0460) 模拟试题及答案详解

(i) Natural Increase = Birth Rate - Death Rate = \(29.5 - 7.5 = 22.0\) per 1,000 per year (or 2.2%).

(ii) Total Dependency Ratio = \(\frac{\text{Number of Dependants (0--14 + 65+)}}{\text{Economically Active Population (15--64)}} \times 100\)
Total dependants = \(16,800 + 4,800 = 21,600\) (or \(35.0\% + 10.0\% = 45.0\%\))
Calculation = \(\frac{21,600}{26,400} \times 100 = 81.818...\% \approx 81.8\%\) (or \(\frac{45}{55} \times 100 = 81.8\%\)).

(i) 22.0 / 22 per 1,000 (or 2.2%) [1 mark]
(ii) Correct method / working shown (e.g. \((16800 + 4800) / 26400 \times 100\) or \(45 / 55 \times 100\)) [1 mark]; Correct final answer: 81.8% / 81.82% / 82 (accept range 81.8 to 82) [0.5 mark]

Sample Answer (Case study: London, UK):

London experiences severe traffic congestion due to high vehicle ownership and commuters travelling into the central business district (CBD) each day.

Problems caused by traffic congestion:
- High levels of atmospheric pollution, notably nitrogen oxides and particulate matter (PM2.5), causing respiratory health issues such as asthma among residents and pedestrians.
- Significant economic losses due to delayed deliveries, lost working hours, and wasted fuel while drivers are stuck in gridlock on major routes such as the M25 and Euston Road.
- Increased noise pollution and visual blight, degrading the quality of life in inner-city neighbourhoods.
- Delays to emergency services (ambulances, fire engines), slowing response times to critical incidents.

Strategies used to manage congestion:
- Implementation of the Central London Congestion Charge (currently £15 per day), which charges private vehicles entering the zone between 07:00 and 18:00 on weekdays, reducing private car volume entering central London by over 15%.
- Introduction of the Ultra Low Emission Zone (ULEZ), penalising vehicles that fail to meet strict emissions standards to reduce air pollution and discourage older, high-polluting vehicles.
- Investment in high-capacity public rapid transit, including the Elizabeth Line (Crossrail) and expanded London Underground services, providing fast, reliable alternatives to driving.
- Expansion of dedicated infrastructure for non-motorised transit, such as Santander Cycles (dockless bike-hire scheme) and segregated Cycle Superhighways (e.g. along the Victoria Embankment), encouraging active commuting.

Level 1 (1–3 marks):
Simple, generic statements describing traffic problems or listing strategies without elaboration.
- e.g. There is air pollution from car exhausts. (1)
- e.g. People are late for work because of jams. (1)
- e.g. They build more cycle lanes and introduce bus lanes. (1)

Level 2 (4–6 marks):
Developed statements describing problems or explaining how strategies reduce congestion/impacts.
- e.g. High concentrations of particulate emissions from idling vehicles cause respiratory conditions like asthma among local residents. (DEV)
- e.g. Charging drivers a daily congestion fee to enter the inner city discourages non-essential car journeys and shifts commuters onto public transit. (DEV)
- e.g. Developing segregated cycle superhighways provides a safe, alternative route for commuters, reducing the number of private cars on the main roads. (DEV)
(Note: Max 5 marks if no named urban area or an inappropriate example is chosen; Max 6 marks if only problems OR only strategies are addressed).

Level 3 (7 marks):
Candidate achieves Level 2 with at least 3 developed points covering both problems and strategies, plus comprehensive place-specific detail (e.g. named locations/schemes, specific local public transit systems, policies, or relevant statistical data).

(i) Location X represents the outer bend of a river meander where lateral erosion forms a steep river cliff.
(ii) At Location X, the thalweg (line of fastest flow) runs along the outside bend where water depth is greatest (3.4 m) and friction is lowest, resulting in high velocity (0.95 m/s) and energetic erosion (abrasion/hydraulic action). At Location Y, on the inside of the bend, water depth is shallow (0.5 m), increasing friction and reducing velocity (to 0.20 m/s); this loss of energy prevents transport and causes sediment to be deposited as a slip-off slope/point bar.

(i) River cliff / river bluff / undercut bank [0.5]
(ii) 1 mark for explanation of deposition at Y, 1 mark for explanation of erosion at X:
• Inner bank (Y): lower velocity / slower flow (0.20 m/s) / shallower water (0.5 m); river loses energy / cannot carry load / increased friction with bed (1)
• Outer bank (X): higher velocity / faster flow (0.95 m/s) / deeper water (3.4 m); river has more energy / hydraulic action / abrasion / undercutting / reduced friction (1)
Note: Must link processes to energy/velocity/depth differences shown in Fig. 3.1.

(i) Longshore drift transports shingle and sand along the shoreline via zig-zag movement (swash at an oblique angle and backwash perpendicular to the shore under gravity).
(ii) The recurved end (Feature B) develops due to a change in the dominant wind/wave direction (or wave refraction around the end of the spit). Behind the spit at Feature C, the area is sheltered from prevailing waves, creating a calm, low-energy body of water where fine sediment drops out of suspension to form mudflats and salt marshes.

(i) Longshore drift / littoral drift [0.5]
(ii) [2 marks max]:
• Curved end (Feature B): secondary wind direction / change in wind or wave direction / wave refraction pushes sediment into estuary / sheltered waters (1)
• Sheltered zone (Feature C): low energy / sheltered from prevailing winds/waves; fine sediments/mud/silt deposit; salt marsh / mudflat develops (1)

(i) Annual temperature range = Maximum mean monthly temperature (28°C) - Minimum mean monthly temperature (27°C) = 1°C.
(ii) Adaptations to the hot, wet equatorial climate:
- Drip-tip leaves: smooth, pointed tips shed excess water rapidly to prevent mold/rot and leaf damage under heavy rainfall.
- Buttress roots: large, flanged above-ground root structures support tall emergent canopy trees in waterlogged, shallow nutrient-poor soils.
- Evergreen broad leaves: year-round warmth and moisture allow continuous photosynthesis without an annual leaf-shedding season.

(i) 1°C [0.5] (Accept 28 - 27)
(ii) 1 mark for each adaptation clearly linked to climatic conditions (maximum 2 marks):
• Drip tips / waxy cuticle (1) - to shed heavy rainfall rapidly / prevent leaf damage / stop fungal growth (1)
• Buttress roots / shallow root network (1) - to support tall trees / absorb nutrients in topsoil in wet conditions (1)
• Broad leaves / evergreen nature (1) - maximizes sunlight capture / continuous growing season due to constant heat and high precipitation (1)
• Epiphytes / lianas (1) - climb tree trunks to access light in dense canopy (1)

(i) Oceanic crust is composed of dense basaltic rock, making it heavier and denser than the lighter, granitic continental crust, causing it to sink into the mantle.
(ii) As the oceanic plate subducts and melts, water and sediment are dragged down, creating silica-rich and gas-rich magma. This high-viscosity magma prevents gas bubbles from escaping easily, building immense pressure that results in explosive eruptions. The thick lava does not travel far before solidifying, layering with pyroclastic material/ash to form steep-sided composite cones.

(i) Oceanic plate is denser / heavier (than continental plate) [0.5]
(ii) [2 marks max]:
• Magma is viscous / thick / sticky / high in silica (1)
• Traps dissolved gases / water / steam, building high pressure leading to explosive eruptions (1)
• Lava solidifies quickly / does not flow far from the vent, forming steep slopes / alternating layers of ash and lava (composite cone) (1)

To achieve full marks (Level 3, 7 marks), candidates must provide:
1. A correctly named, valid example of a tropical rainforest (e.g., Amazon Rainforest, Borneo Rainforest).
2. Developed statements explaining the causes of deforestation (e.g., cattle ranching, soy farming, infrastructure, logging, mining).
3. Developed statements describing the impacts on the natural environment (e.g., loss of biodiversity/habitat fragmentation, topsoil erosion and siltation of rivers, reduction in evapotranspiration altering microclimate, carbon cycle disruption and enhanced greenhouse effect).
4. Authentic place-specific detail (e.g., named regions like Mato Grosso, specific infrastructure like the Trans-Amazonian Highway/BR-163, named rivers like the Xingu/Tapajós, or specific species affected).

Level 1 (1–3 marks):
- Simple, generic, unelaborated statements describing causes or impacts of deforestation.
- Examples:
- Trees are cut down for timber / farmland.
- Roads are built through the forest.
- Animals lose their habitats / plants die.
- Soil is washed away by rain.
- Carbon dioxide is released.
(1 mark for each valid simple point, up to 3 max)

Level 2 (4–6 marks):
- Developed statements explaining causes and/or describing environmental impacts in detail.
- Examples:
- Large areas are cleared for cattle ranching and commercial soy farming to meet rising international export demand (DEV).
- The removal of the dense canopy exposes bare soil to heavy downpours, leading to rapid leaching of nutrients and topsoil erosion (DEV).
- The reduction of forest cover reduces evapotranspiration rates, leading to drier local microclimates and increased risk of forest fires (DEV).
- Felling and burning trees releases large volumes of stored carbon into the atmosphere, reducing the global carbon sink and accelerating global warming (DEV).
(1 developed point = 4 marks, 2 developed points = 5 marks, 3+ developed points = 6 marks. Max 5 marks if no named example or inappropriate example is used).

Level 3 (7 marks):
- Meets all Level 2 criteria (minimum of 3 developed statements covering both causes and environmental impacts).
- Includes comprehensive, authentic place-specific detail (e.g., named locations such as Mato Grosso / Pará, specific highways such as the Trans-Amazonian Highway / BR-163, named river systems like the Xingu, or specific conservation/species data).

To achieve full marks (Level 3, 7 marks), candidates must provide:
1. A correctly named, valid example of a tropical rainforest (e.g., Amazon Rainforest, Borneo Rainforest).
2. Developed statements explaining the causes of deforestation (e.g., cattle ranching, soy farming, infrastructure, logging, mining).
3. Developed statements describing the impacts on the natural environment (e.g., loss of biodiversity/habitat fragmentation, topsoil erosion and siltation of rivers, reduction in evapotranspiration altering microclimate, carbon cycle disruption and enhanced greenhouse effect).
4. Authentic place-specific detail (e.g., named regions like Mato Grosso, specific infrastructure like the Trans-Amazonian Highway/BR-163, named rivers like the Xingu/Tapajós, or specific species affected).

Level 1 (1–3 marks):
- Simple, generic, unelaborated statements describing causes or impacts of deforestation.
- Examples:
- Trees are cut down for timber / farmland.
- Roads are built through the forest.
- Animals lose their habitats / plants die.
- Soil is washed away by rain.
- Carbon dioxide is released.
(1 mark for each valid simple point, up to 3 max)

Level 2 (4–6 marks):
- Developed statements explaining causes and/or describing environmental impacts in detail.
- Examples:
- Large areas are cleared for cattle ranching and commercial soy farming to meet rising international export demand (DEV).
- The removal of the dense canopy exposes bare soil to heavy downpours, leading to rapid leaching of nutrients and topsoil erosion (DEV).
- The reduction of forest cover reduces evapotranspiration rates, leading to drier local microclimates and increased risk of forest fires (DEV).
- Felling and burning trees releases large volumes of stored carbon into the atmosphere, reducing the global carbon sink and accelerating global warming (DEV).
(1 developed point = 4 marks, 2 developed points = 5 marks, 3+ developed points = 6 marks. Max 5 marks if no named example or inappropriate example is used).

Level 3 (7 marks):
- Meets all Level 2 criteria (minimum of 3 developed statements covering both causes and environmental impacts).
- Includes comprehensive, authentic place-specific detail (e.g., named locations such as Mato Grosso / Pará, specific highways such as the Trans-Amazonian Highway / BR-163, named river systems like the Xingu, or specific conservation/species data).

(i) According to Fig. 3.1, Country Z uses 44% of its water for domestic purposes, which is higher than Country W (8%), Country Y (17%), and Country X (30%).
(ii) Country W agriculture = 82%; Country X agriculture = 18%. Difference = \(82\% - 18\% = 64\%\).
(iii) Low-income countries predominantly have agrarian economies where a large proportion of the workforce is engaged in farming, requiring large-scale irrigation for subsistence and cash crops, while industrial manufacturing and piped household water networks are less widespread.

(i) Country Z [0.5]
(ii) 64(%) [1] (Accept \(82 - 18 = 64\))
(iii) 1 mark for a valid explanation, such as: Large proportion of workforce in farming / primary sector dominance; extensive irrigation required for crops / subsistence farming; lower domestic piped water access / fewer water-intensive domestic appliances; less manufacturing / industrial development to consume water. [1]

(i) Coal decreased from 65% in 2000 to 40% in 2020 (a decrease of 25 percentage points), which is the largest decrease.
(ii) Renewable sources in 2020 = Hydroelectric (12%) + Solar & Wind (13%) = \(12\% + 13\% = 25\%\).
(iii) Burning coal releases greenhouse gases like carbon dioxide and pollutants like sulfur dioxide; reducing coal combustion lowers emissions that cause climate change, smog, and acid rain.

(i) Coal [0.5]
(ii) 25(%) [1] (Allow 1 mark for correct answer or working showing \(12 + 13\))
(iii) 1 mark for a valid environmental advantage: Reduction in greenhouse gas emissions / \(\text{CO}_2\) / mitigation of global warming; less sulfur dioxide / nitrogen oxides / reduction in acid rain; reduced air pollution / smog; less habitat destruction from coal mining / open-cast extraction. [1] (Do not accept vague answers like 'cleaner' or 'better for environment' without qualification).

(i) Country S has 48% of workers in the secondary sector, which is the highest among all listed countries.
(ii) Country R has 74% in the tertiary sector, which represents the majority (over 50%).
(iii) As a country develops, agricultural mechanisation (tractors, combine harvesters) reduces the demand for farm labour, while industrialisation and the growth of services (retail, banking, healthcare) create higher-paying jobs in urban areas, leading to rural-to-urban migration and a shift in employment structure.

(i) Country S [0.5]
(ii) Tertiary (sector) AND 74(%) [1] (0.5 for sector, 0.5 for percentage)
(iii) 1 mark for a valid explanation: Mechanisation / use of machinery in farming reduces need for farm workers; rural-to-urban migration / pull to factory and service jobs; higher wages in secondary/tertiary sectors; depletion of raw materials / commercialisation of farms. [1]

(i) Quarter 3 had the highest arrivals with 480,000 tourists.
(ii) Total annual expenditure = \(\$90\text{ million} + \$210\text{ million} + \$420\text{ million} + \$120\text{ million} = \$840\text{ million}\).
(iii) During the off-peak quarters (Quarter 1 and Quarter 4), hotels and tour companies cut staff, resulting in seasonal unemployment, inconsistent income, and financial insecurity for local residents.

(i) Quarter 3 / Q3 / Jul–Sep [0.5]
(ii) $840 million / 840,000,000 (US) dollars [1] (Accept 840 with units clearly implied)
(iii) 1 mark for a valid problem: Seasonal unemployment / laid off in low season; fluctuating / insecure income; difficulty budgeting for the entire year; reliance on second / informal jobs during off-peak periods; overwork / long working hours during peak months. [1]

**Example Case Study: Singapore (The Four National Taps)**

* **Local catchment water:** Singapore has constructed reservoirs and an extensive network of drains, canals, and rivers across the island to capture surface runoff. The Marina Barrage created the country's first reservoir in the city centre by damming the Marina Channel, turning saltwater into freshwater and collecting rainwater from a large urban catchment area.

* **Imported water:** Water has historically been imported across the Straits of Johor from the Johor River in neighbouring Malaysia under bilateral water agreements. This raw water is transported via pipelines and treated in Singapore to supplement local reserves.

* **High-grade reclaimed water (NEWater):** Advanced water recycling facilities collect and treat wastewater/sewage effluent using multi-stage membrane technologies, including microfiltration, reverse osmosis, and ultraviolet disinfection. Plants such as Changi Water Reclamation Plant and Bedok NEWater factory produce ultra-clean water mainly used for wafer-fabrication plants, industrial cooling, and indirect potable top-ups in reservoirs during dry periods.

* **Desalinated seawater:** Seawater from the surrounding sea is desalinated at major plants such as the SingSpring Desalination Plant and Tuas Power-Spring Desalination Plant, utilizing energy-efficient reverse osmosis membranes to remove dissolved minerals and salts, ensuring a drought-resilient water source for domestic and industrial use.

**Level 1 (1–3 marks):**
* Simple statements describing or listing methods of water supply without elaboration.
* *Examples:* They build reservoirs to store rain; water is taken from rivers; they clean dirty water; they import water from another country.

**Level 2 (4–6 marks):**
* Developed statements explaining how water is collected, treated, distributed, or managed to provide a supply to people and industry.
* *Examples:* Reservoirs have been constructed in urban catchment areas behind barrages to collect surface runoff and prevent it from flowing out to sea; wastewater undergoes advanced membrane filtration and reverse osmosis to produce high-grade recycled water for high-tech industries and cooling.
*(Max 5 marks if no named example or inappropriate example used)*

**Level 3 (7 marks):**
* Achieves Level 2 (at least three developed statements).
* Includes accurate, authentic **place-specific details** (e.g., named reservoirs/plants, specific geographic locations, accurate project names, or relevant statistics).
* *Example:* References specific facilities like Marina Barrage, Bedok NEWater plant, Changi Water Reclamation Plant, or the Johor River agreement with technical specifics.