The complex and spatially diverse patterns of hydrological droughts
across Europe
Abstract
This study presents a new dataset of gauged streamflow (N=3,224) for
Europe spanning the period 1962 to 2017. The Monthly Streamflow of
Europe Dataset (MSED) is freely available at http://msed.csic.es/. Based
on this dataset, changes in the characteristics of hydrological drought
(i.e. frequency, duration, and severity) were assessed for different
regions of Europe. Due to the density of the database, it is possible to
delimit spatial patterns in hydrological droughts trend with the
greatest detail available to date. Results reveal bidirectional changes
in monthly streamflow, with negative changes predominating over central
and southern Europe, while positive trends dominate over northern
Europe. Temporally, two dominant patterns were noted. The first pattern
corresponds to a consistent downward trend in all months, evident for
southern Europe. A second pattern was noted over central and northern
Europe and western France, with a predominant negative trend during warm
months and a positive trend in cold months. For hydrological drought
events, results suggest a positive trend toward more frequent and severe
droughts in southern and central Europe and conversely a negative trend
over northern Europe. This study emphasizes that hydrological droughts
show complex spatial patterns across Europe over the past six decades,
implying that hydrological drought behaviour in Europe has a regional
character. Accordingly it is challenging to adopt “efficient”
strategies and policies to monitor and mitigate drought impacts at the
continental level.