AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
(B) Increase in natural fertilisation of flood plains due to silt deposit
Building dams actually deprives flood plains of silt (a natural fertiliser), leading to land degradation — the opposite of increased fertilisation.
Source: Water Resources, Chapter 3 (Multi-purpose River Projects and Integrated Water Resources Management)
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The passage clearly states that "sedimentation also meant that the flood plains were deprived of silt, a natural fertiliser." Options A, C, and D are all directly listed as consequences of large dams in the source text. Option B describes a benefit that dams actually destroy, making it the "NOT a consequence" answer. Watch for trick questions where the opposite of a stated effect is given as an option.