Reference
Pekarova, P., Miklanek, P. and Pekar, J. 2003. Spatial and temporal runoff oscillation analysis of the main rivers of the world during the 19th-20th centuries. Journal of Hydrology 274: 62-79.
What was done
The authors analyzed the annual discharge rates of selected large rivers of the world for recurring cycles of wet and dry periods. For those rivers with sufficiently long and accurate data series (primarily European rivers), they also derived long-term discharge rate trends.
What was learned
In the words of the authors, "the trend analysis does not show any significant trend change in long-term discharge series (1810-1990) in representative European rivers," including the Goeta, Rhine, Neman, Loire, Wesaer, Danube, Elbe, Oder, Vistule, Rhone and Po.
What it means
It is interesting that even over the 180-year time period that saw the demise of the Little Ice Age and the ushering in of the Modern Warm Period, there were no long-term trends in the discharge rates of the major rivers of Europe. Does this observation suggest that earth's hydrologic cycle may not be as sensitive to global warming as climate alarmists claim it is? It's difficult to say for sure, due to inadequate river discharge data from many parts of the world; but the discharge data of Europe's major rivers sure don't support the contention!
Reviewed 19 November 2003