The next IAHS decade on hydrological change (2013-2023)

panta_rheiThe success of PUB (see related blog post here) lead IAHS to start a new decadal initiative starting in 2013 during the IAHS General Assembly held in Göteborg, Sweden. This new decade focuses on hydrological change and its connection to society. It is named Panta Rhei meaning “Everything flows”. This expresses that everything (above all, water) is in a state of never ending change. Similar to the HEPEX Science and Implementation Plan, the Panta Rhei science plan was written through community crowd sourcing (lead by Alberto Montanari).

The new IAHS decade has three main targets:

Target 1 – Understanding, to improve the knowledge and understanding of hydrological systems;
Target 2 – Estimation and prediction, to estimate and predict the behaviors and patterns of hydrological systems, with uncertainty assessment to support risk evaluation;
Target 3 – Science in practice, to address societal needs, policy making and implementation.

In addition, several science questions are formulated which do include core HEPEX themes. The initiative asks for example: “How can we advance our monitoring and data analysis capabilities to predict and manage hydrological change?” – something which is important for ensemble generation, hydrological modeling, pre-processing, post-processing and data assimilation (to name a few). Panta Rhei also aims to set up strategies for estimating and communicating uncertainty and solutions for reducing decision-making and operational uncertainty (which is another of the HEPEX science questions).

For the complete Panta Rhei science plan, see:

How do HEPEX and Panta Rhei complement each other?

Panta Rhei complements HEPEX by focusing on many aspects which are important for operational hydrology. It explicitly states that it “will place emphasis on transferring science development into practice through encouraging the direct involvement of policy makers, operational services and research institutes in the scientific work and discussion”. Many of us in HEPEX know how difficult that can be, in particular merging operational reality and cutting edge research.

Our community’s strength lies in focusing on a specific topic and addressing the components which form part of it. The HEPEX community consists of many practitioners, researchers and policy makes from a wide background. Panta Rhei takes a broader hydrological scientific approach than HEPEX, but is born out of the midst and strength of hydrological science at IAHS. Of course there is overlap and we should harvest this to engage new members in our community and build better Hydrological Ensemble Prediction Systems.

What do you think?


  1. Dear Colleagues,
    Thank you for the attention you are puntting on Panta Rhei. I think HEPEX and Panta Rhei are extremely relevant each other and I would very much welcome the contribution of the HEPEX community to Panta Rhei, by proposing a research theme or a working group.
    An open call for research themes and working groups will be issued soon on the Panta Rhei web site, at Please keep an eye on the web site and do not hesitate to contact me if you need more details.
    All the very best,
    Alberto (Chair of Panta Rhei 2013-15)

    1. Thank you Alberto for your comment – we will be proposing a working group as soon as this is possible!


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