Date | November 2014 | Marks available | 4 | Reference code | 14N.2.hl.7 |
Level | HL only | Paper | 2 | Time zone | |
Command term | Describe | Question number | 7 | Adapted from | N/A |
Question
The chart shows the total number of hurricanes that struck a country per decade from 1851 to 2010.
Describe the trends shown on the graph.
(i) Outline the essential characteristics of drought.
(ii) Explain the cause(s) of one named drought event.
“The level of economic development is the most important factor that influences the vulnerability of a population to environmental hazard risks.” Discuss this statement.
Markscheme
Award [1 mark] for each of the following trends, and exceptions to/clarifications of the trends identified:
- general trend is up to 1941–51, then down to 1991–2001
- or may see a rise to 1891–1900, then general decline to 2010 but with some marked exceptions
- recent upturn 2001–2010, or since 1971–80 (with exceptions)
- rising trend is interrupted by anomalies at 1861–70, or 1901–10, 1921–30
- may view lows at 1921–30 (18) and highs at 1941–50 (34) as interrupting a trend of some sort
- after 1941–50 there were fewer than 25 hurricanes
- 1941–50 showed a sharp rise in the number of hurricanes [1 mark]
- a fluctuating trend
- other valid comments that identify a trend, or exceptions/anomalies to that trend.
(i) Award [1 mark] for a valid definition of drought, and an additional [1 mark] for development. For example:
Lower rainfall than the long-term average [1 mark] for a prolonged period of time [1 mark]
OR
With resulting impacts on the environment or human activity as a result of water shortages [1 mark].
(ii) Award [1 mark] for the timing (accept some margin of error) and general location of one drought event eg 2008–09 in Australia. Award up to [3 marks] for the explanation that follows.
For instance, credit any of the following ideas, if applied in a valid context:
- El Niño event [1 mark] when Pacific trade wind reversal [1 mark] increased air pressure in Australia 2008 [1 mark] bringing dry, subsiding air [1 mark]
- La Niña event [1 mark] when Pacific trade wind strengthening [1 mark] resulted in colder eastern Pacific Ocean and high pressure [1 mark] leading to drought in Texas in 2011 [1 mark]
- Excessive use of water by humans [1 mark]. Over-extraction of groundwater, or over-irrigation [1 mark] resulted in water shortages [1 mark] and drought in Australia in 2010 [1 mark].
Credit other valid examples and approaches.
Credit all content in line with the markbands. Credit unexpected approaches wherever relevant.
Most responses will support the statement but high-scoring answers must present an argument to support their viewpoint that also examines other factors. Answers could refer to factors such as investment in warning systems, public education/awareness, effective lines of communication, preparedness and quality of emergency response, insurance, building codes, ability to coordinate the above. These are usually better developed in richer societies. Very good answers may refer to the fact that even in richer countries, some sections of the population are more vulnerable than others (may use case study of New Orleans, for example).
Other factors not related to economic development could include population density, knowledge of the area, culture, the magnitude of the hazard and the type of area (eg coastal) that the population inhabits.
For band D candidates must describe how economic development affects vulnerability with reference to at least one hazard type.
Band E should either provide much greater detail of a range of hazard risks that are related to economic development or discuss the concept of vulnerability in relation to at least one additional factor, such as population distribution.
At band F, expect both elements.
Examiners report
There were some very good responses showing the numerous trends on the graph. However, some identified patterns rather than trends.
Drought was generally misunderstood, with many simply stating that it was a period of low rainfall. Causes seemed to be for arid regions rather than for specific drought events. There were, however, some good answers referring to recent drought in Australia and its physical and human causes.
This was done well with some comprehensive responses including good contrasting case studies. Weaknesses included not applying the answer to a range of hazards or writing at length about other factors.