(i) Define the term groundwater.

(ii) Estimate the percentage of groundwater shown on the diagram.

State two major types of natural surface freshwater (other than rivers).

Explain three consequences of a reduction in the volume of ice caps.

Discuss the relative importance of the factors affecting the characteristics of hydrographs.

(i) Water found below the surface of the earth [1 mark].

(ii) Accept answers in the range 25–30 % (inclusive) [1 mark].

Accept lakes, wetlands (marshes or swamps), depression storage/surface storage.

Award [1 mark] for each source identified.

Accept any of the following. In each case, award [1 mark] for a valid consequence and [1 mark] for a valid explanation. For example:

• coastal flooding/inundation [1 mark] due to rising sea levels/more water stored in oceans [1 mark]
• relocation of coastal settlements [1 mark] due to heightened long-term flood risk [1 mark] (but do not credit suggestion that massive flooding occurs “overnight” leading to death and destruction)
• accelerated global warming [1 mark] due to albedo reduction as ice melts [1 mark]
• loss of productive agricultural land [1 mark] due to saline intrusion/contamination of freshwater
• landscape changes as land-based glaciers retreat [1 mark] due to moraine deposition etc [1 mark]
• possible river flooding [1 mark] due to melting of ice caps/glaciers [1 mark].

Credit other valid consequences and explanations.

Credit all content in line with the markbands. Credit unexpected approaches wherever relevant.

One approach would be to look at a single river: temporal variations are based on factors such as precipitation (amount, intensity, type), antecedent rainfall and seasonal changes in vegetation/interception. Another approach is to compare a different river: geology, soils and land-use (urbanization), drainage basin size and shape, relief, all play an important role.

Factors should be linked with characteristics that can include rising limb, falling limb, lag-time and peak discharge. Diagrams should be credited.

Certain domain factors could be identified such as geology (when discussing different basins), or antecedent conditions (when discussing variations in response to two similar sized rainfall events). Urbanization over time is a key factor that can transform hydrographs. Clearly, any evaluation of relative importance is context specific.

At band D, a range of factors should be described that are linked to some recognizable hydrograph characteristics.

At band E there should be either a wider or structured discussion of factors (may compare different basins, as well as considering seasonal changes or urban/rural contrasts) or a viewpoint is argued about the relative importance of factors (but for a more limited range of factors/scenarios).

At band F, expect both elements.

(i/ii) No problems encountered.

These had to be natural and surface, for example, lakes, springs. Too many candidates named oceans, aquifers, reservoirs and were therefore unable to identify a second type of freshwater.

Generally done well although the explanations were sometimes very descriptive rather than backing up the consequence.

There were some very good answers showing that hydrographs and the factors affecting their characteristics are being well taught. There were some good annotated diagrams and terminology was clear. The main weakness was not considering the relative importance of the factors. However, many wrote generalized answers on rivers and showed no understanding of the term hydrographs.