Describe the process of river capture and its effects, using evidence from a case study.

1.1.1

River capture, also known as river piracy, is a geomorphological process where a stronger, more energetic river erodes its watershed boundary (divide) through headward erosion and diverts the headwaters of a weaker, less energetic river into its own channel.

1.1.2

*a) The high-lying area labelled A: Watershed or Interfluve

*b) A resultant feature of river capture labelled B: Elbow of capture

1.1.3

The evidence from the case study is: "whereas the Mohlapitse, deprived of the previously strong flows is now a soggy and confused wetland, uncertain of how it will gather strength and flow down into the distant Olifants River."

1.1.4

After river capture, the Great Lethaba River will experience:

• An increase in its volume of water because it has captured the headwaters of the Mohlapitse River.
• An increase in its velocity and erosive power due to the greater volume of water. This is supported by the text stating, "Today the Lethaba River flows fast and clear at this spot".

1.1.5

The impact on farming activities along the Mohlapitse River after river capture would be significant and negative:

• Reduced water availability: The Mohlapitse River, having lost its headwaters, will have significantly less water, making irrigation for crops difficult or impossible.
• Changes in river characteristics: The river will become a "soggy and confused wetland" as described, leading to waterlogging in some areas and insufficient flow in others, which is unsuitable for most farming practices.
• Economic hardship: Farmers dependent on the Mohlapitse River for water will face crop failure, reduced yields, and potential abandonment of agricultural land, leading to economic losses.