Using Figure 4 and your own knowledge, assess the relative importance of factors leading to the development of this landscape - AQA - A-Level Geography - Question 2 - 2021 - Paper 1

To assess the relative importance of factors contributing to the development of the barchan dunes in the Namib Desert, we need to evaluate key environmental conditions and processes that have played a significant role.

Key Factors Influencing Development

1. Wind Patterns: The consistent wind direction and velocity are crucial in shaping the barchan dunes. Winds come predominantly from the northwest, which helps in the transportation of sand. The steady winds also lead to a regular shaping of the dunes, causing them to migrate over time.

2. Sediment Supply: The Orange River serves as a primary sediment source, delivering sand that is deposited in the desert. The availability of sand is essential for the formation and growth of barchan dunes. Without a sufficient supply of sediments, the dunes cannot develop.

3. Erosion and Deposition Processes: Erosion caused by wind action is vital in sculpting the landscape. The processes of deflation (removal of loose particles) and deposition (accumulation of sand) work together to create and maintain these unique landforms. Erosional patterns allow for the migration of sand, contributing to the dynamic nature of the barchans.

4. Geographical Location: The arid environment of the Namib Desert is ideal for the formation of barchans. The lack of vegetation reduces the stability of sand, while the dry climate ensures minimal moisture intrusion, allowing for continuous erosion by wind.

Conclusion

In summary, while sediment supply is essential for initial dune formation, wind patterns play a significant role in their ongoing development and movement. The interplay between these factors highlights the relative importance of geological and environmental processes in shaping the landscape of the Namib Desert.