ACSI 2025 Prelims P1 HL QP - Ans

1 Anglo-Chinese School (Independent) PRELIMINARY EXAMINATION 2025 IB DIPLOMA PROGRAMME YEAR 6 (IBDP 2) Geography Higher Level Paper 1 Tuesday 2 September 2025 2 hours 15 minutes Instructions to candidates • Write your class and candidate number on this cover page. • Do not open this examination paper until instructed to do so. • Answer the questions in three options. • The accompanying geography resource booklet is required for this examination paper. • Use examples, maps and/or diagrams where relevant. • The maximum mark for this examination paper is [60 marks]. • Please attach this cover sheet to the answer script. Class: …………………………………. Candidate number 0 0 2 3 2 9 Marks Option D – Geophysical hazards /20 Option E – Leisure, tourism and sport /20 Option G – Urban environments /20 Total /60 _______________________________________________________________ This question paper consists of 4 printed pages.

2 Answer the questions in three options. When relevant, answers should refer to case studies or examples, and where appropriate include well‑drawn maps or diagrams. Option D – Geophysical Hazards Answer the following question. 1. Refer to the map on page 2 of the accompanying resource booklet. The map shows the lahar hazard zones of Kanloan Volcano in the Philippines. (a) Describe the direction and range of the lahar hazard. [2] The Lahar Hazard Map of Kanlaon Volcano shows that lahar hazards extend radially from the volcano along river valleys and drainage pathways. [1m] [Award 1m for any of the following] West & Southwest (La Carlota City, La Castellana): • High to moderate hazard zones extend up to 16 km, affecting multiple barangays and settlements. South & Southeast (Moises Padilla): • Lahars can reach 10–14 km, with high hazard zones concentrated within ~8 km of the summit. Northeast & East (San Carlos City, Vallehermoso, Canlaon City): • Hazards extend 10–12 km, but generally in narrower pathways following rivers. Northwest (Murcia, Bago City): • Hazard zones stretch up to 12–16 km, with moderate to low hazard levels dominating the outer areas. (b) Outline one reason why some places may be at greater risk of lahars. [2] [1m for the reason, 1m for the explanation] • Proximity to the volcano: Settlements closer to Kanlaon’s slopes face higher hazard levels because lahars are more concentrated and faster-moving near the source. • Location along river valleys: Lahars follow drainage channels, so communities, farms, and infrastructure built along rivers are directly in their path. • Population density and land use: Densely populated towns, built-up areas, and agricultural land in low-lying floodplains are more vulnerable to lahar damage compared to sparsely settled areas.

3 (c) Explain how volcanic hazard risk could be a product of geographic factors. [3] [1m for the geographic factor, 2m for the explanation] • Relief and topography: Steep volcanic slopes and deep river valleys channel hazards such as lahars, pyroclastic flows, and landslides, increasing risk for settlements in these pathways. • Climate and rainfall: In tropical regions with heavy rainfall (like the Philippines), rain can easily mobilize volcanic ash and debris into destructive lahars, raising the hazard risk. • Population distribution and land use: Towns, farms, and infrastructure located on fertile volcanic soils around the volcano face greater exposure, making the risk higher compared to sparsely inhabited or elevated areas. (d) Suggest what governments can do to better manage volcanic hazards. [3] [1m for the factor, 2m for the explanation] • Monitoring and early warning systems: Invest in seismographs, gas sensors, and satellite monitoring to detect volcanic activity early and issue timely evacuation alerts. • Land-use planning and zoning: Restrict settlements and farming in high-hazard zones (e.g., river valleys prone to lahars) and develop safer resettlement areas. • Public education and preparedness: Conduct regular community drills, hazard awareness campaigns, and school-based programs so people know evacuation routes and safety measures. Answer either part (a) or part (b). Either 2. (a) Examine the relationship between plate boundary type and the characteristics of associated tectonic hazards. [10] Core Ideas / Main Points Constructive (Divergent) Boundaries: • Hazards: Mainly effusive volcanic eruptions (basaltic lava, shield volcanoes), shallow earthquakes. • Characteristics: Generally less explosive, lower magnitude earthquakes, hazards often localized but can affect ocean ridges/islands (e.g., Iceland). Destructive (Convergent) Boundaries: • Hazards: Explosive volcanic eruptions (andesitic/rhyolitic magma, composite volcanoes), powerful earthquakes, tsunamis.

4 • Characteristics: High magnitude, wide-reaching impacts, often most destructive (e.g., Japan 2011 earthquake & tsunami, Mount Pinatubo eruption). Conservative (Transform) Boundaries: • Hazards: Frequent, shallow-focus earthquakes; no volcanoes. • Characteristics: Earthquakes can be very destructive if near population centers (e.g., San Andreas Fault, Turkey earthquakes). Intra-plate Hazards (Hotspots & Rifts): • Hazards: Volcanism away from plate boundaries (e.g., Hawaii, Yellowstone). • Characteristics: Can produce either effusive (Hawaii) or explosive (Yellowstone) hazards, showing exceptions to plate boundary patterns. Overall Relationship: • Type of boundary influences magma type, earthquake depth, and hazard magnitude/frequency. • Human vulnerability and preparedness also determine the impact, so plate boundary type explains the hazard characteristics but not the full risk. Or 2. (b) Examine the effectiveness of different hazard-mitigation strategies in reducing loss of life and property damage from mass movements. [10] Core Ideas / Main Points 1. Engineering and Structural Strategies o Examples: Retaining walls, rock bolts, check dams, slope terracing, drainage systems. o Effectiveness: Can significantly reduce slope failure and protect infrastructure in high-risk areas (e.g., Hong Kong slope management). o Limitations: High cost, requires maintenance, may fail in extreme events. 2. Land-Use Planning and Zoning o Examples: Restricting settlements on steep slopes, creating exclusion zones, reforestation. o Effectiveness: Prevents people and property from being exposed to hazards, long-term sustainable solution. o Limitations: Enforcement may be weak, relocation of communities can be politically and socially difficult.

5 3. Monitoring and Early Warning Systems o Examples: Rainfall thresholds, ground movement sensors, satellite imagery, hazard mapping. o Effectiveness: Provides time for evacuation, especially in rainfall-induced landslides and lahars (e.g., Philippines lahar warning systems after Pinatubo). o Limitations: False alarms may reduce trust, not all events can be predicted. 4. Community Preparedness and Education o Examples: Evacuation drills, public awareness campaigns, training in hazard response. o Effectiveness: Reduces loss of life by ensuring rapid, organized responses when hazards occur. o Limitations: Less effective at protecting property, relies on consistent funding and participation. 5. Overall Evaluation o Structural strategies are most effective at reducing property damage. o Non-structural strategies (education, planning, early warning) are often more effective at reducing loss of life. o Best outcomes come from integrated approaches, combining engineering, planning, and preparedness. End o