| Date | May 2021 | Marks available | 2 | Reference code | 21M.1.bp.1 |
| Level | SL and HL | Paper | 1 | Time zone | |
| Command term | Outline | Question number | 1 | Adapted from | N/A |
Question
The table shows the location and height, in metres, of the world’s tallest waterfalls.
[Source: Adapted from https://www.worldwaterfalldatabase.com/tallest-waterfalls/total-height. Information presented on the World Waterfall Database is constantly being re-evaluated and while we strive to keep it as accurate as possible, there are entries in our Tallest list(s) which need to be more closely scrutinized and as such the heights we currently have presented may or may not be entirely accurate.]
Identify which country has the most waterfalls between 780m and 860m in height.
State the mode for height from the table.
Outline the main features of one landform, other than a waterfall, created by river erosion.
Explain two reasons why rates of erosion could vary at different waterfalls, such as those shown in the table.
Markscheme
USA.
840 (“m” not needed).
Award [1] for a basic outline of a valid landform and [1] for further development of its main feature(s) or the process relating to its formation.
For example: A meander is a winding/sinuous section of a river [1] with a steep river cliff on the outside bend [1].
Other erosional landforms include:
- gorges
- v-shaped valleys
- plunge pools
- rapids
- potholes
- terraces
- ox-bow lakes.
In each case, award [1] for a valid reason and [2] for further explanation/development of variation in rates of erosion at different waterfalls.
For example: If the drop in height is great [1], the water will be very fast [1]; therefore, there will be more rapid abrasion/hydraulic action [1].
Other possible reasons include:
- geology
- scale / size of drainage basin
- variations in discharge levels
- load causing abrasion in plunge pool.
Examiners report
1 (a)(i) and (ii) Very few issues here.
1 (a)(i) and (ii) Very few issues here.
Many named a landform, e.g. meander, correctly but did not outline the main feature(s) of the landform. Some candidates outlined features of river deposition.
Most made a good attempt at this although many asserted that velocity and discharge were two different factors.
