Using this graphic and referring to it is encouraged, and please use it in presentations, web pages, newspapers, blogs and reports.
For any form of publication, please include the link to this page and give the cartographer/designer credit (in this case Philippe Rekacewicz, UNEP/GRID-Arendal)
Igor A. Shiklomanov, SHI (State Hydrological Institute, St. Petersburg) and UNESCO Paris, 1999.
Uploaded on Saturday 25 Feb 2012
Trends in continental river discharge
Philippe Rekacewicz, UNEP/GRID-Arendal
River flow is cyclical in nature, with alternating cycles of wet and dry years. This graphic uses bar graphs to show the average annual volumes of river runoff in cubic kilometres for each continent from 1921 to 1985. Over the time period the discharge there has been no obvious trends, but a certain degree of fluctation, the level dependent on the area of the basins and the precipitation over the area. The sizes of the bars in this graph reflect the level of precipitation over the respective continents.