A meandering river is flowing in a broad,alluvial valley and the river is silt-laden but also moves sand and a small amount of gravel.The government decides to build a dam across the valley for power and flood control.What will happen to the river downstream of the dam?
A)The river will start to deposit sand and gravel,frequently spilling out of its channel.
B)The river will not change.
C)The river will respond to the new temporary base level and cut laterally outside its valley,widening the valley.
D)The trapping of silt in the reservoir will change the river to a braided stream because it will only have sand and gravel in its sediment load.

Question

Quizplus · Accepted Answer

The dam will trap silt in the reservoir, reducing the fine sediment load downstream. This can lead to a change in the river's sediment dynamics, potentially causing it to become a braided stream due to the remaining coarser sediment like sand and gravel.

A Meandering River Is Flowing in a Broad,alluvial Valley and the River