Chapter 28, Problem 7TE

What three variables influence the speed of stream flow?

To determine

The three variables that influence the speed of stream flow.

Answer to Problem 7TE

The three variables that influence the speed of stream flow are stream gradient, stream discharge, and channel geometry.

Explanation of Solution

The variables that are responsible for the influence of the streamflow speed are channel geometry, stream discharge, and stream gradient. Stream discharge is the amount of water that crosses a given point in a particular time period. The speed of streamflow varies linearly to the stream discharge. Moreover, the area of the stream is kept constant, and discharge is increased, the speed also increases.

Channel geometry provides a description of shape of the channel. It greatly influences the amount of discharge that can be carried by a channel and the speed of the stream. If the area of a channel is more, it can carry more discharge. Also, for the same discharge, if the area is less, then the stream's speed will be more.

Stream gradient, or also known as steepness, refers to the slope of the channel stream. The stream speed will be more when the gradient is steep, as the effect of gravity will be greatest. Therefore, the gradient of a stream greatly influences the stream speed.

Conclusion:

Therefore, the three variables that influence the speed of stream flow are stream gradient, stream discharge, and channel geometry.