For example, if your five-day study period is May 26–30, you would calculate the average flow of the Lena thus:
5/26/2000 5/27/2000 5/28/2000 5/29/2000 5/30/2000
41454 74880 93720
116471 110207
(41454 + 74880 + 93720 + 116471 + 110207) / 5 = 87,346 m3/s Enter this value in the box under the Lena for the year 2000 in the table at the end of the student page.
5. Repeat this process for each river for the year 2000. Then repeat the entire process for 2001, 2002, and so on.
If a river has no data for your study period on a given year, write NA (not applicable) in the box for that year.
In the end, you should have the entire table filled in for your study period.
6. Now you will turn your data into a chart. Use the y-axis (the vertical line) for cubic meters per second of flow. Use the x-axis (the horizontal line) for years.
Find the highest and lowest values for your y-axis from the chart. Start your y-axis slightly lower than the lowest value and divide it into equal portions until you reach the highest value. The x- axis will consist of the seven years in the study period.
Use a different colored pencil to mark the data for each river on the graph. Then make a line that connects the dots.
7. Compare your chart with the charts of the rest of your group. Is there a trend in the seven-year study period? What conclusions can you draw about the rate of water flow during this period? Is it a large enough sample to draw any conclusions about an increase in freshwater flow? Why, or why not?
Now compare your results with the rest of the class. Can you identify a trend across the seasons?