ABSTRACT

Describing the evolution of trends from historical hydrological variables, such as streamflow or precipitation, is a difficult task as data are often incomplete in the spatial and temporal domains. Evidence indicates an ongoing intensification of the water cycle, although to date, on a global scale, no consistent trends support an increase in the frequency or intensity of floods. The data set consists of daily runoff series collected from the French Banque Hydro Archive. Streamflow indices were selected in order to describe the evolution of high flows. The trend analysis was carried out applying statistical tests to the time series of the streamflow indices. The idea behind the use of regional tests is that stations located in the same region, that are subject to similar climate, are most likely to behave in the same way to the evolution of climate forcings.