manauswater.jpg
This image displays two scientific graphs, labeled A and B, which present data regarding precipitation and water levels of the Rio Negro river. The entire graphic is black and white.

Graph A is a combination chart located at the top. It has an X-axis representing months from January to December. There are two Y-axes. The left Y-axis represents Mean precipitation in millimeters (mm), ranging from 0 to 300. The right Y-axis represents Rio Negro water level, specifically the mean from 1987 to 2007, ranging from 18 to 30.

The legend at the top indicates that white vertical bars represent Precipitation and a black line with diamond markers represents the Rio Negro water level.
- The precipitation bars show high rainfall in February (around 280 mm) and March (around 270 mm). January is around 175 mm, April and May are near 190 mm. From June through September, precipitation drops significantly to below 100 mm. October is the lowest at roughly 60 mm, with November rising slightly to 90 mm and December jumping back up to 200 mm.
- The line graph for water level starts low in January (around 22), rises steadily through spring, peaking in June/July around 28 meters. It then declines sharply through autumn, reaching a minimum in November (around 19) before rising slightly in December.

Between the two graphs is a citation text that reads: From Pia Parolin, Submerged in darkness: adaptations to prolonged submergence by woody species of the Amazonian floodplains, Annals of Botany, Volume 103, Issue 2, January 2009, Pages 359–376. A URL is also visible: https://doi.org/10.1093/aob/mcn216

Graph B is a line chart located at the bottom. The X-axis represents Years from 1987 to 1999. The Y-axis represents Rio Negro water level in meters above sea level (m a.s.l.), ranging from 15 to 29.
- The graph shows a repeating cyclical pattern of peaks and troughs for each year.
- In 1987, the level starts around 23, peaks near 28, drops to roughly 18, then rises again.
- This cycle repeats annually. For example, in 1989, there is a very high peak reaching nearly 29 meters.
- The lowest point on the entire graph occurs in late 1997, where the water level drops below 16 meters.
- The highest peaks generally occur around mid-year (June/July) and reach between 28 and 29 meters.
- The troughs generally occur towards the end of the year (October/November) and drop to between 15 and 17 meters.
This description was generated automatically. Please feel free to ask questions if you have further questions about the nature of the image or its meaning within the presentation.