Outline four ways in which urbanization may influence processes in the hydrological cycle.

Hydropower is a resource that can be exploited from rivers. Explain how the value of this resource to a society may vary over time.

To what extent are water scarcity issues better addressed through changing human behaviour than through technological development?

urban (paved) surfaces/reduced veg cover will lead to increase in run-off;
…and thus increase stream-flow/flooding;
urban (paved) surfaces/reduced veg cover will reduce infiltration of water into soils;
…and thus reduce inputs to groundwater/aquifers/water table level;
urbanization can increase heat/local temperature leading to greater evaporation/downwind precipitation;
urbanization will reduce vegetation cover and thus reduce evapotranspiration/regional precipitation;
urbanization will increase local water extraction reducing river flows/increasing outputs from groundwater storages/aquifers;
urbanization may lead to increased emission of greenhouse gases/global warming /climate change that may result in multitude of changes in hydrological cycle e.g. increased melting of glaciers/shifting precipitation patterns/increased evaporation etc.;
urbanization may lead to increased emissions of NO_x/SO_x leading to acid precipitation;

Note: Ensure that each markpoint includes an explicit link to a direct consequence of urbanization and how this influences a process in the hydrological cycle.
Award [1] max for changes associated with global warming.

Positive changes promoting the value of hydropower:
rise in environmental awareness/need for renewable energy may increase value of hydropower;
need for industrial development entails increased demand for energy, thus increasing value of hydropower;
improved/more efficient technology of dam building making the political decision more attractive to voters / increasing the margin of profit / reducing the initial investment for LEDCs / making overall project more sustainable;
technological development of small scale/damless projects may render hydropower more aesthetically appealing / cheaper to implement in LEDCs / more environmental-friendly / more fit to ecocentrists;
hydropower may become favoured due to depletion in local non-renewable sources/need for energy security;

Negative changes reducing value of hydropower:
impacts of hydropower on aquatic systems / local human settlements cause increasing conflict with cultural values/local needs;
other renewable resources may become more favourable through technological development/reduced costs;
decreasing rainfall/increased evaporation due to climate change renders an existing dam less efficient / profitable;
energy security reasons / political change / economic recession dictate shift from hydropower to more dense nuclear power / cheaper coal;
societal values/EVS may stop seeing damming of a river as sustainable and demand shift away from river dams to wind/solar power;
society realizing it was unethical to relocate a local tribe and demanding the restoration of the river;

Note: Do not credit general arguments on dynamic nature of natural capital, unless explicitly linked to hydropower or clearly discussed in the context of hydropower.
Do not credit any argument relating to the high value (monetary, intrinsic, aesthetic, environmental, cultural, economic, ethical, social, spiritual, technological) of hydropower, if not explicitly shown how this value has changed over time. (e.g. local Native American tribe resents river diversion due to its spiritual value; this is not a valid MP, as no change shown, just a different value system).

Refer to paper 2 markbands, available under “your tests”  tab > supplemental materials Positive changes.

The following guide for using the markbands suggests certain features that may be offered in responses. The five headings coincide with the criteria given in each of the markbands (although “ESS terminology” has been conflated with “Understanding concepts”). This guide simply provides some possible inclusions and should not be seen as requisite or comprehensive. It outlines the kind of elements to look for when deciding on the appropriate markband and the specific mark within that band.

Answers may include:

• understanding concepts and terminology of water accessibility, distribution, security, scarcity; approaches of different EVS to water management; management policies/legislation; irrigation; domestic use; industrial development; international conflict; water conservation strategies; desalination; artificial recharge of aquifers; rainwater harvesting; grey-water recycling, etc.;
• breadth in addressing and linking changes in human behaviour and technological approaches with a range of water conservation strategies in the context of different societies and geographical locations, etc.;
• examples of water scarcity issues and changes in human behaviour and technological solutions that may address these issues, etc.;
• balanced analysis evaluating the extent to which changes in human behaviour address water scarcity more effectively than technological solutions along with limitations and counterarguments, etc.;
• a conclusion that is consistent with, and supported by, analysis and examples given e.g. “although technological solutions often become necessary when scarcity is particularly severe, changing human behaviours address the root of the problem and have a more widespread affordability”;

The majority of candidates seemed to approach this question with confidence but were often too generalised and failed to specifically identify impacts on 'processes' of the water cycle like percolation, infiltration, run-off, transpiration etc.

The majority of candidates could identify two or three causes of a change in the dynamic value of hydropower but few extended their imagination to gain full credit for this question.

There was a tendency in addressing this question for candidates to prioritise small scale water saving strategies around personal ablutions and laundry rather than more extensive behaviours like those associated with global warming, population growth or food production. While there was generally some understanding of technological strategies like desalination and drip-irrigation these were often assessed as less significant than turning the tap off while cleaning teeth.