Social Science (087) — AI-generated practice question

Construction of dams affects the aquatic ecosystem and agricultural land in the following ways:

1. Aquatic ecosystem: Regulating and damming rivers causes poor sediment flow and excessive sedimentation at the reservoir bottom, resulting in rockier stream beds and poorer habitats for aquatic life. Dams fragment rivers, making it difficult for aquatic fauna to migrate, especially for spawning.

1. Agricultural fertility: Flood plains are deprived of silt — a natural fertiliser — as sedimentation occurs within the reservoir instead of being deposited downstream. This leads to land degradation and loss of natural soil fertility in surrounding agricultural areas.

Source: Multi-purpose River Projects and Integrated Water Resources Management, Chapter 3

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The examiner expects two clear impacts — one on the aquatic ecosystem and one on agricultural land fertility — each explained with specific details from the textbook. Key terms to include: sediment flow, sedimentation, spawning, silt, natural fertiliser, land degradation. Avoid generic statements; use textbook language. Since it is 3 marks, 3 distinct points (or 2 well-explained points) work well. Do not write about displacement or other unrelated dam impacts.