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This question is based on the hypothetical scenario described below - NSC Marine Sciences - Question 5 - 2024 - Paper 1
Question 5
This question is based on the hypothetical scenario described below. Kwaaihoek is a coastal region found along the east coast of South Africa near East London. This... show full transcript
Worked Solution & Example Answer:This question is based on the hypothetical scenario described below - NSC Marine Sciences - Question 5 - 2024 - Paper 1
Step 1
Explain how dunes are formed.
Answer
Dunes are formed through a process where sediment is transported from inland rivers by longshore drift towards the coast. This sediment is then deposited when wind action slows down and the sediment falls to the ground. The primary process involves:
- Sediment transportation: Winds carry sand from the beach inland.
- Formation of ridges: As the wind deposits the sediment, it creates ridges known as dunes.
- Gradients of wind: The size and shape of dunes are influenced by wind direction and speed.
- Vegetative stabilization: Vegetation plays a crucial role in stabilizing the dunes, preventing erosion.
Step 2
Discuss the role vegetation plays in the formation of a stable dune ecosystem.
Answer
Vegetation is crucial in maintaining the integrity of dune ecosystems. Key roles include:
- Root systems: The roots of plants like grass and shrubs help anchor the sand, reducing erosion and sand movement.
- Moisture retention: Vegetation increases the retention of moisture in the dunes, aiding in the growth of more plants.
- Biodiversity: A stable dune ecosystem supports various species, enhancing ecological diversity.
- Nutrient cycling: Decomposing plant matter enriches the soil, providing nutrients essential for plant growth.
Step 3
Describe the TWO different engineering approaches that can be used AND compare their effectiveness for this site.
Answer
The two engineering approaches include:
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Hard Engineering: This involves constructing artificial structures such as seawalls, groynes, or breakwaters to combat erosion and control sand movement. While effective in stopping immediate erosion, it may have high costs and can disrupt natural sediment flow.
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Soft Engineering: This includes methods such as planting vegetation or creating sand fences to naturally stabilize the dunes. It is less intrusive and is more sustainable, offering long-term stability without significantly altering the natural landscape.
Comparison:
- Effectiveness: Hard engineering is often quick and visually impactful but may lead to unforeseen consequences like increased erosion down the coast. Soft engineering, while slower to establish, promotes a healthy ecosystem and can be more adaptable to changes in the environment.
Step 4
Motivate whether it is important to conduct an environmental impact assessment (EIA) before deciding on the type of engineering approach to use.
Answer
Conducting an EIA is vital as it allows specialists to assess the potential negative impacts of the proposed engineering solutions. It ensures that:
- Sustainable practices: Evaluates how the project would affect local ecosystems, guiding towards environmentally-friendly options.
- Community involvement: Engages stakeholders, ensuring that local communities are informed and their concerns are considered.
- Long-term effects: Provides a thorough understanding of how the proposed solutions will interact with existing ecosystems over time.
Step 5
Justify whether constructing an engineering structure would benefit the local municipality.
Answer
Constructing an engineering structure could benefit the local municipality by making tourist locations more accessible, which would likely enhance local tourism and economic growth. However, it is essential to consider:
- Initial costs vs. long-term benefits: While the construction may require significant investment, the return could foster job creation and increased revenue from tourism.
- Environmental consequences: If the chosen structure leads to ecological degradation, the long-term costs may outweigh immediate benefits.
- Social impacts: Improved accessibility could increase local crime rates or over-tourism, necessitating careful planning and consideration of community impacts.