Date | November 2021 | Marks available | 6 | Reference code | 21N.1.bp.1 |
Level | SL and HL | Paper | 1 | Time zone | |
Command term | Suggest | Question number | 1 | Adapted from | N/A |
Question
The satellite image shows part of the Red Rock River in Montana, USA.
[Source: U.S. Geological Survey, n.d. Site map for Montana. [online] Available at: https://waterdata.usgs.gov/mt/nwis/
nwismap/?site_no=06011500&agency_cd=USGS [Accessed 1 October 2020]. Source adapted.]
State the direction from point A to point B.
Estimate the percentage of the satellite image that is covered by dense vegetation.
Outline the relationship between river discharge and hydraulic radius.
Suggest two landform changes that could be caused by river processes in an environment such as this.
Markscheme
South-east
About 20 % (accept 10–30 %)
Award [1] for the basic relationship and [1] for further development (either explanation or other outlined development, e.g. mention of Bradshaw model).
For example: The relationship is positive [1] / they both increase with distance downstream [1] as the river’s size and energy increases [1].
Do not award marks for definitions.
In each case, award [1] for a valid landform change resulting from fluvial processes, and up to [2] for development / explanation / exemplification.
For example: a meander develops into an ox-bow lake [1] when river erosion cuts through the neck of the meander [1] and deposition continues to isolate the lake [1].
Other possibilities which are appropriate for the lowland fluvial environment shown in the photograph include:
- Meanders - accept increasing, more sinuosity, formation implying change
- Levees - formation implying change
- Floodplains - formation implying change
- Deltas
- Slip-off slope / river cliff
- River terraces.
Examiners report
These caused no problems.
These caused no problems.
Most could identify a positive relationship but lacked development; often just defining the terms instead of explaining the relationship.
The key word in the question was "changes" which was often ignored; many just described the formation of a landform. The main landforms used were meanders, oxbow lakes and levees. A few candidates tried to use waterfalls, which are unlikely to be found in a floodplain landscape such as the one depicted in the image.