Date | November 2018 | Marks available | 6 | Reference code | 18N.2.bp.2 |
Level | SL and HL | Paper | 2 | Time zone | |
Command term | Explain | Question number | 2 | Adapted from | N/A |
Question
The map extract shows part of the Sagarmatha National Park in Nepal. The scale is 1:50 000 and the contour interval is 40 metres.
State the direction of flow of the Phungi Khola river at A.
Using map evidence, outline one reason why the Phungi Khola river is likely to have seasonal variations in its discharge.
Using map evidence, state why river discharge at B is likely to be significantly higher than at C throughout the year.
Explain two hydrological changes that may result from the construction of a dam in an area such as the Sagarmatha National Park.
With reference to one named river basin, discuss the different strategies used to meet the competing demands on the water supply.
Markscheme
North West [1]
The river flows from the glacier [1], which melts more in the summer [1].
Award [1] for stated evidence that two rivers join between the two points / there is a confluence.
In each case, award [1] for identifying a change, and [2] for further explanation.
For example: The reservoir behind the dam would function as a water store [1], which allows control of the flow of water over the year [1], resulting in a more even seasonal discharge downstream [1].
Other possibilities include:
- less erosion/more deposition downstream
- or more erosion if sediment has been trapped by dam
- increased sedimentation in the reservoir
- increased evaporation
- decreased river flow
- increased storage
- increased infiltration.
Responses will depend on the river basin chosen. The river basin should be named and located.
The competing demands should be outlined and could include farming, industry, domestic supplies, recreation and power supply.
Strategies could include:
At a local scale – reducing demand by water metering, customer advisory services, regulation of the efficiency of water-using appliances, especially in new buildings, water-use restriction (temporary or permanent), leakage detection and repair programmes and pressure reduction.
National scale – dams and reservoirs, transfer of water, zoning, the use of incentives for installation and/or retrofitting of water-efficient equipment, reduction of water use by the water utility, use of reclaimed water (eg waste water/grey water) to reduce the need for fresh water supplies.
Good answers may discuss the varying power and/or perspectives of different user groups in relation to how a resolution is arrived at (commercial/human need for water may ultimately take precedence over the needs of ecosystems/wetlands, for instance). Another approach might be to evaluate the importance/success of strategies/actions or look at different scales of approach.
Answers that do not refer to a named river basin and focus on demands only should not move beyond band C.
At band D, expect description of some strategies used to tackle water demand problems in a recognizable river basin.
At band E, expect either more in-depth explanation of strategies, or some critical evaluation of how successful the strategies have been in relation to meeting competing demands.
At band F, expect both.
Marks should be allocated according to the Paper 2 markbands (available under the "Your tests" tab > supplemental materials).