This session is cosponsored by the International Association of Hydrological Sciences (IAHS) and the World Meteorological Organization's Commission for Hydrology (WMO/CHy) and is related to the new scientific decade 2013–2022 of IAHS, entitled “Panta Rhei – Everything Flows”. Panta Rhei is dedicated to research activities on change in hydrology and society and the study of the changing dynamics of the processes governing the water cycle in connection with rapidly changing human systems.

Water cycle processes are also tightly linked to climate: Water vapour is by far the most important greenhouse gas; conversely, diachronic changes to climate impact hydrology. While hydrological change is influenced by many factors in addition to climate, and climate includes processes other than hydrological, nonetheless it would seem that one has to study water cycle and climate together, particularly if one wants to characterize future hydrological conditions -- e.g. water availability or flood hazards – and uncertainties thereof. However, the two corresponding scientific disciplines employ very different tools, methods and logics. Although a number of sessions focus on assessing impacts of climate and hydrological change, this session seeks papers exploring the more fundamental physical interface between climate and hydrology, focusing on their societal aspects: What can hydrology offer to climate science, and vice versa, and what can both offer to study change and its interaction with the society? Papers that explore how hydrological and climatological data can be employed to improve our understanding of the physical processes associated with climate, to calibrate models, to improve forecasts and predictions, to estimate correspono
ding uncertainties, and to investigate societal concerns about hydrological and climate changes, are particularly sought.