Physical Geography and Fluvial Systems

In the sample graph above (from 2011), you can immediately see that the amount of water flowing past the stream gauge has gone down for the last 30 days (the blue line). One interesting thing they include on this graphic is the median statistics. This means that the discharge over the history of the station (57 years in this case) has had as many days over the triangle as below. So, for the last 57 years, there have been 28 years where water has been higher than the triangle, and 28 years when the water has been below the triangle on the same date.

1. Copy and paste this graphic from your site here: (2 points)

2. Explain the discharge curve and how it compares to the median values: (2 points)

The second graph (also from 2011) displays the actually height of the stream at the gage. This is the base information from which all the other data are derived.

The key information on this graph is how high the gage height is above the flood stage. This graph shows that while the stream height has been going down for the last 30 days, it is still almost a foot above the flood stage. The flood stage is the level at which the stream is officially considered flooded. The stream height can go up and down quite a bit and still be considered ‘normal.’
3. Copy and paste your Gage Height graph here: (2 points)

4. Explain how the current gage height relates to the flood stage: (2 points)

5. In general, why do you think the graphs look this way for your site? Are you in a drought? Is it wetter than usual? Explain. (2 points)

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