Question
Option A — Freshwater
The map shows the major wetland areas within the Murray–Darling river basin in the state of New South Wales in Australia.
Answer either part (a) or part (b).
Either
(a) Examine the view that it is increasingly difficult to predict river flooding.\([10]\)
Or
(b) Examine why water management issues might be a cause of conflict between stakeholders.\([10]\)
▶️Answer/Explanation
Ans:
(a) Marks should be allocated according to the markbands.
Prediction of frequency and magnitude of river flooding is increasingly difficult,
especially with the impact of climate change on weather systems and uncertainty
in climate modelling. Human activity within drainage basins can also increase the
risk of flooding in unpredictable ways. However, it may be argued that with the
increasing power of computer technology, weather satellites, remote sensing and
monitoring stations, river floods are easier to predict. But this may only apply to
advanced industrial societies.
Possible applied themes (AO2) demonstrating knowledge and
understanding (AO1):
• River flooding is an increasing problem, partly due to the effects of climate change
on weather systems and rainfall patterns, and also because of human activities
altering the characteristics of drainage basins.
• Flood prediction involves: weather forecasting, to determine precipitation inputs
(amount, intensity and duration), and analysis of the hydrograph characteristics
of drainage basin to determine river responses and the possibility of flooding.
• Weather forecasting, using data collection, satellite technology, and computer
modeling is becoming more accurate. Also, instrumentation of drainage basins
makes flood prediction (timing and intensity) more reliable.
• Possible long-term changes to weather systems caused by climate change has
increased the uncertainty of climate modeling and unpredictability of weather
systems.
• The increasing impact of human activity on drainage basins, (including
deforestation, urbanization and channel modification) impacts on characteristics
of storm hydrographs and increase the risk of flooding.
Good answers may be well-structured (AO4) and may additionally offer a critical
evaluation (AO3), which examines processes and systems affecting the accuracy and
reliability of forecasting flood events in different places. Another approach might be to
examine how future risks may increase over longer time scales.
For 5-6 marks, expect some weakly-evidenced outlining of the difficulties and/or ease of
predicting river flooding.
For 7-8 marks, expect a structured account which includes:
• either an evidenced explanation of the difficulties and/or ease of predicting flooding due
to climate change, human activity, technology.
• or a discursive conclusion (or ongoing evaluation of the different views) grounded
in geographical concepts and/or perspectives.
For 9-10 marks, expect both of these traits.
(b)
(b) Examine why water management issues might be a cause of conflict between
stakeholders. [10]
Marks should be allocated according to the markbands.
Water management issues include agricultural activities, tourism, domestic and
industrial use, all of which can have a significant impact on water quality. The focus
should be on the problems of water management and the differing, sometimes
conflicting, views of stakeholders.
Possible applied themes (AO2) demonstrating knowledge and understanding (AO1):
• Management of water may give rise to conflict between different stakeholders. These include farmers, tourism, local communities, agribusiness, planners, water authorities, government agencies, scientists and national governments.
• Stakeholders, of different powers, may have conflicting views and perspectives regarding the management of water.
• Agricultural activities adversely affect water quality through eutrophication and irrigation/salinization.
• The differing views of stakeholders must be reconciled in order for water to be managed for a sustainable future.
• There could be cooperation between stakeholders to manage water use. Good answers may be well-structured (AO4) and may additionally offer a critical evaluation (AO3), which examines the power of different stakeholders in relation to the conflicts caused by water management issues, and the possibilities for management at different scales and places.
For 5-6 marks, expect some weakly-evidenced outlining of at least one water management issue.
For 7-8 marks, expect a structured account which includes:
• either an evidenced examination of the difficulties of managing water and the roles/power of different stakeholders
• or a discursive conclusion (or ongoing evaluation) grounded in geographical concepts and/or perspectives. For 9-10 marks, expect both of these traits.
Question
Outline how water is transferred through a drainage basin by:
(i) infiltration;
(ii) throughflow.
Suggest how a change in the balance of water stored in oceans and ice could result in:
(i) one environmental consequence with positive effects for people;
(ii) one environmental consequence with negative effects for people.
“The benefits gained from the construction of large dams outweigh any costs.” Discuss this statement with reference to one or more major dams.[10]
▶️Answer/Explanation
Markscheme
(i)
Award [1] for a simple description and [1] for some development.
For example:
Infiltration is the downward movement of water [1] from the surface/into the soil [1] / may be influenced by vegetation cover/slope angle/human impact [1].
(ii)
Award [1] for a simple description and [1] for some development.
For example:
Throughflow is the sideways/lateral movement of water within the soil [1] where downward movement is restricted [1] / moves through pores/cracks/fissures or natural pipes in the soil [1].
(i)
Consequences include: retreat of glaciers and ice shelves / ice caps; accessibility to more land (for farming); new sea floor resources found; increased water supply; changes in tourism; new shipping routes.
Award [1] for the consequence and [2] for development and/or exemplification.
For example: Arctic ice melting [1] is allowing the discovery of previously unknown oceanic resources [1], eg oil [1].
(ii)
Consequences include: rising sea levels caused by ice melt; flooding in low-lying areas; drowned features on coastlines or emergent features; coastal inundation; increased river flows; water insecurity; changes in tourism; environmental refugees.
Award [1] for the consequence and [2] for development and/or exemplification.
For example:
Ice melt is causing rising sea levels [1] which are inundating coastal areas/low-lying islands, eg Pacific atolls [1] leading to migration [1].
At least one example of a major dam should be named and located. Both benefits and costs should be discussed.
Costs could include: biodiversity loss; increased siltation; changing river load downstream (and water temperature change with ecosystem impacts); loss of water through increased evaporation; increased chances of diseases (such as bilharzia); loss of nutrients due to flood control; salinization; seismic activity; increased landslides; forced migration/displacement of population; loss of farmland; loss of historic sites; drowning of settlements; disruption of transport links.
Benefits include: power generation; industrialization; economic spin-off; prestige, water supply; irrigation; transport/navigation; flood control; supplements low river levels; fishing; recreation and tourism.
Good candidates may question from whose perspective the statement is made or may apply concepts. Another approach may be to apply scale or timescale, ie many people benefit over a broad area while only local people lose their homes, or the benefits and costs may only become clear over time.
To access band D, there should be description of some costs and benefits – do not expect balance.
For band E, there should be either explanation of a greater range/depth of costs and benefits or some discussion of the statement (considers perspective, scale, time, etc).
For band F, expect both.
Marks should be allocated according to the markbands.
Examiners report
The meanings of the terms “infiltration” and “throughflow” were often imperfectly understood. The use of a diagram sometimes helped the answer, and due credit was given.
This was generally well answered. A variety of different consequences was acceptable, but answers were often not sufficiently developed to warrant full marks.
Some excellent responses, mainly using Three Gorges Dam, the Hoover Dam and Aswan Dams as examples. The best answers gave range/variety/detail of costs and benefits, in relation to the particular dams chosen, and were able to make some overall evaluation. Sometimes, however, answers were general and descriptive.
Question
Outline two environmental problems that may occur downstream from multi-purpose dams.[4]
Define the concept of “maximum sustainable yield” of freshwater.[2]
With reference to one named river basin, explain two strategies that have been adopted to meet competing demands for water.[4]
“The negative consequences of river flooding always outweigh the benefits.” Discuss this statement.[10]
▶️Answer/Explanation
Markscheme
In each case, award [1] for a valid problem and [1] for development.
For example: Reduced nutrient transport downstream [1], resulting in decreased agricultural/fisheries yields [1].
Problems could include:
• loss of biodiversity
• increased risk of salinization
• less water for agriculture
• clear water erosion
• decreased fish stocks
• flooding due to dam collapse
Accept other creditable suggestions as long as they are downstream from the dam.
The maximum level of extraction of water [1] that can be maintained indefinitely for a given area [1].
Alternative acceptable definitions include:
• the relationship/balance between inputs and outputs [1] so that water does not run out for the foreseeable future/on an annual basis [1]
• the largest amount of water that can be taken from a resource [1] without depleting the original source or potential for replenishment [1].
In each case, award [1] for a valid strategy, and [1] for further development.
Award a maximum of [3] if no example is given.
One approach is to manage the conflicting needs of different user groups, eg farmers, industries and domestic users. Another approach is to tackle the issue of too many domestic users competing for limited water.
For example: In the Colorado River basin: state administrations impose quotas [1] for different user groups, eg casinos/golf courses [1], restricting consumption in order to conserve water. At the local scale, homeowners in any city are competing for a limited amount of water and have to implement their own conservation measures, eg flushing the toilet less often [1]. This is encouraged by grants for low-flush toilets [1].
Other possibilities include:
• domestic pricing
• rationing
• water metering
• conservation measures, eg shorter showers, re-use of grey water, replacing grass with sand and succulents, more efficient irrigation systems – drip rather than sprinkler, desalinization projects
• storage of water: eg dams/reservoirs
• inter-basin water transfer.
Answers would be expected to discuss the advantages and disadvantages of river flooding.
The benefits of flooding could include the formation of floodplains; areas of flat land; fertile alluvial soils suitable for agriculture; areas for human settlement; formation of wetland ecosystems; maintaining ecosystems; re-charging of groundwater. Opportunities may exist, for example, for aquaculture; some economies are closely connected to the flood cycles.
The negative consequences of floods may include loss of life, damage to infrastructure, housing and farmland. Economic and social losses may be substantial, especially in urban areas on floodplains.
It may also be argued that the information gained from a river flood helps guard against future inundations, and that frequent monitoring and management strategies may reduce the impact of flooding. Similarly, it may be argued that river flooding is largely beneficial and that many ancient civilizations depended on the regular flooding of rivers. However, because of climate change and other human factors, flood frequency and magnitude has increased.
Good answers would be expected to discuss in detail the potential advantages and disadvantages of flooding in a way that arrives at a final evaluation. An alternative approach would be to provide a structured discussion of the statement from different perspectives, as these may differ on what constitutes a benefit or cost.
At band D, expect a description of some consequences of river flooding.
At band E, expect either more detailed explanation of the advantages and disadvantages of river flooding or a structured discussion of the statement.
At band F, expect both of these elements.
Marks should be allocated according to the markbands.