Long-term properties of annual maximum daily river discharge worldwide
Bouziotas, D., G. Deskos, N. Mastrantonas, D. Tsaknias, G. Vangelidis, S.M. Papalexiou, and D. Koutsoyiannis,
European Geosciences Union General Assembly 2011, Geophysical Research Abstracts, Vol. 13, Vienna, EGU2011-1439, European Geosciences Union, 2011.
We use a database of annual maximum daily discharge time series (World Catalogue of Maximum Observed Floods, IAHS Press, 2003) and extract those with length greater than 50 years. We analyse extreme floods at several stations worldwide focusing on their long-term properties of the time series including trends and persistence (else known as Hurst-Kolmogorov dynamics), which characterizes the temporal streamflow variability across several time scales. The analysis allows drawing conclusions, which have some importance, given the ongoing and intensifying discussions about worsening of climate and amplification of extreme phenomena.
Analysis of trends and of aggregated time series on climatic (30-year) scale does not indicate consistent trends worldwide. Despite common perception, in general, the detected trends are more negative (less intense floods in most recent years) than positive. Similarly, Svensson et al. (2005) and Di Baldassarre et al. (2010) did not find systematical change neither in flood increasing or decreasing numbers nor change in flood magnitudes in their analysis. READ PAPER