We investigate changes that occurred in small vs. big flood events and in small vs. large catchments across Europe over 5 decades. Annual maximum discharge series between 1960 and 2010 from 2370 gauges in Europe are analysed. Distinctive patterns of flood regime change are identified for large regions across Europe, which depend on flood magnitude and catchment size.

We investigate the seasonal memory properties of a large sample of European rivers in terms of high and low flows. We compute seasonal correlations between peak and low flows and average flows in the previous seasons and explore the links with various physiographic and hydro-climatic catchment descriptors. Our findings suggest that there is a traceable physical basis for river memory which in turn can be employed to reduce uncertainty and improve probabilistic predictions of floods and droughts.

This study uses remotely sensed river discharge data to correct river storage and discharge in a large-scale hydrological model. The method is based on an ensemble Kalman filter and also introduces an additional technique that allows for better constraint of the correction (called localization). The approach is applied over the entire Amazon basin. Results show that the method is able to improve river discharge and localization to produce better results along main tributaries.

The paper presents an index of summer flood damage in Switzerland from 1800 to 2009 and explores the influence of solar forcing, climate variability and low-frequency atmospheric circulation on flood frequencies. The flood damage index provides evidence that the 1817-1851, 1881-1927, 1977-1990 and 2005-present flood clusters are mostly in phase with palaeoclimate proxies and solar activity minima. Floods are influenced by atmospheric instability related to the principal summer mode.

Natural patterns of water levels in the Mekong are changing as a result of hydropower and irrigation development. Since 1991, significant changes in water level fluctuations and rising and falling rates have occurred along the lower Mekong. The changes were linked to temporal and spatial trends in water infrastructure development and can lead to impacts on ecosystem productivity. Climatic change is also important, but it has not been the main cause of the key water level alternations.