If a river’s velocity suddenly decreases, what will it do with its carried load?

Correct answer: It will start depositing it

The governing concept is the relationship between river velocity, carrying capacity and deposition. Faster water has greater energy and can transport larger or heavier particles. When the velocity suddenly decreases, the river loses some of its transporting power. The load may then become too heavy or too large to remain suspended or move along the bed, so sediment begins to settle. Therefore option C is correct: the river starts depositing its carried material. Erosion is more likely where flowing water gains energy, not where it slows. Sediment is not changed into vapour, and although some substances can dissolve in water, a river does not always dissolve its load; much of the load consists of solid sand, silt, gravel or clay.