| Date | May 2012 | Marks available | 2+2+2 | Reference code | 12M.2.bp.1 |
| Level | SL and HL | Paper | 2 | Time zone | |
| Command term | Explain | Question number | 1 | Adapted from | N/A |
Question
The diagram shows the inputs, outputs, stores and transfers that occur within a drainage basin as an open system.
[Source: adapted from http://www.bbc.co.uk/scotland/education/int/geog/rivers/images/basin/diag_processes.gif]
Identify two transfers and two stores shown in the diagram.
Explain three ways in which human activity can reduce the time taken for water to pass through the system.
Examine how an international conflict has arisen as a result of competing demands for freshwater.
Markscheme
Award 2 marks for the correct identification of two stores (interception, surface water, soil moisture, groundwater, channel) and 2 marks for the correct identification of two transfers (soil infiltration, percolation, overland flow, throughflow, groundwater flow). No marks should be awarded for the identification of evapotranspiration or river enters the sea as a transfer.
Answers depend on the human activity/activities chosen which may lead to land use changes (urbanization, deforestation, agriculture), river channel modifications, drainage systems. Marks should not be allocated to “increased rainfall”.
Award 1 mark for correct identification of a relevant human activity and 1 mark for a valid explanation of how it reduces the time taken for water to pass through the system.
The freshwater water resource involved should be clearly identified and located, as should the countries involved in the water conflict.
Answers should clearly describe the nature of the conflict and explain why it occurs.
The associated problems for each of the countries involved should be examined. Attempts to resolve the conflict can lead to further conflict and this can be credited where relevant.
Answers that refer only to a conflict within a country should not move above band C.
Marks should be awarded according to the markbands.
Examiners report
Knowledge and understanding was good.
Weaker candidates often failed to unpack the term "human activity". Popular choices were urbanization, deforestation and river channel modifications.
Many answers were based on the USA–Mexico conflict over usage of the River Colorado, but specific details of this (or other chosen examples such as the Nile basin or the Jordan) were often shaky. Some accounts were overly descriptive and insufficiently focused on the details of the conflict. Where candidates wrote about more than one example, the higher-scoring example was credited.
