Geology Labs
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The amount of water flowing in a stream is called its DISCHARGE, which is the volume of water moving in a stream during a given time interval. Time is usually expressed as seconds, but volume can be in cubic feet (ft3) or cubic meters (m3). So, discharge can be either cubic feet per second (ft3/s, also termed cfs) or cubic meters per second (m3/s). We'll be using the metric system for our determinations, but at the end of this activity you have the opportunity to convert from m3/s to cfs.

Click "Start" to observe the block of water move downstream at a rate of 1.0 meters per second. (It takes 10 seconds for the cubic meter block to move 10 meters.) The example stream above is confined to a 1 meter square channel. Discharge here then, is 1.0 cubic meters/s. Later in this exercise you will determine the cross-sectional area of a stream and the stream's velocity through that area. By multiplying the area times the stream's velocity, you will be able to estimate the stream discharge.

Answer these questions:

1. Discharge is an important concept. What statement best describes stream discharge?
It's a measure of stream volume per distance traveled It's a measure of stream velocity It's a measure of how much water is moving past a certain location along the stream each second.

2. If the stream above were moving twice as fast, what would the discharge be?
2.0 cubic meters/s 0.5 cubic meters/s 1.5 cubic meters/s




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