Question

Jean lives in a city where a river flows into the ocean and there is a birdfoot delta. She sees on the news that a reservoir with a dam is going to be built on the river. The water stored in the reservoir will provide for all the local communities. What is most likely to happen to the delta after the reservoir is built?

A. It will get larger.
B. It will get smaller.
C. It will stay the same.
D. It will form a sand dune.

Answer 1

The birdfoot delta is most likely to get smaller after the reservoir is built due to changes in the river's ecology.

Step-by-step explanation:

When a river reaches the ocean or a large lake, the water typically slows dramatically and any silt in the river water will settle. Rivers with high silt content discharging into oceans with minimal currents and wave action will build deltas, low-elevation areas of sand and mud, as the silt settles onto the ocean bottom.

A reservoir and operation of the dam can affect the natural water habitat due to changes in water temperatures, chemistry, flow characteristics, and silt loads, all of which can lead to significant changes in the ecology and physical characteristics of the river upstream and downstream.

Based on these effects, it is most likely that the birdfoot delta in Jean's city will get smaller after the reservoir is built.