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Difficulty: Very hardEnvironmental Hazards and Resource Management in Nigeria

Environmental degradation in Nigeria exhibits distinct spatial patterns across its ecological zones. While the southeastern scarp lands of Anambra and Imo experience severe gully erosion driven by friable sedimentary formations and intense torrential rainfall, the low-lying Atlantic coastline of Lagos and the Niger Delta suffers from coastal surge flooding and rapid shoreline retreat. Which of the following resource management measures offers the most structurally effective long-term defense against coastal erosion and beach loss along Nigeria's Atlantic shorelines?

  1. A
    Establishing dense shelterbelt belts of drought-resistant Acacia and Eucalyptus species along the littoral margin.
  2. Constructing heavy coastal engineering structures such as groynes, seawalls, and artificial beach nourishment.Answer
  3. C
    Mandating targeted oil spill remediation procedures under the statutory enforcement scope of NESREA.
  4. D
    Practicing contour ploughing and slope terracing along littoral agricultural land gradients.

Answer

Constructing heavy coastal engineering structures such as groynes, seawalls, and artificial beach nourishment.
The correct answer emphasizes direct physical coastal engineering interventions (groynes, seawalls, breakwaters, and beach nourishment). Coastal erosion along Nigeria's Atlantic coastline (such as the Bar Beach and Lekki coastal areas in Lagos) is driven by persistent high-energy wave action, ocean tides, and longshore drift. Installing groynes traps moving sand along the beach, seawalls shield coastal property from wave impact, and replenishment restores eroded shoreline buffers.

Step-by-Step Solution

1
Analyze the spatial hazard type and geographical setting presented in the stem.
The hazard is marine coastal erosion and shoreline retreat along Nigeria's southern Atlantic coastline (Lagos and Niger Delta).
Different ecological zones in Nigeria require hazard management tailored specifically to the dominant destructive forces operating in those environments.
2
Evaluate the coastal mechanics driving beach loss and marine inundation.
Marine shoreline erosion is driven by high-energy ocean wave action, longshore drift, tidal surges, and coastal land subsidence.
Mitigation measures must directly counteract or dissipate marine kinetic energy and stabilize littoral sediment movement.
3
Assess candidate management strategies for coastal engineering suitability.
Groynes trap littoral sediment along the shore, sea walls act as hard barriers reflecting storm wave energy, and artificial nourishment restores lost beach material.
Hard coastal protection structures combined with soft nourishment constitute the standard engineering response to marine coastal recession.

Key Concept

Spatial Zonation of Environmental Hazards and Targeted Management Strategies in Nigeria
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Topics

Environmental Hazards and Resource Management in Nigeria

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