Free Flow

While IAHS is developing its science plan for the next

decade, UNESCO is developing the 8th Phase of the

International Hydrological Programme (IHP) covering

the period 2014-2021. The emphasis here is on water

security, recognized as a key challenge for the 21st

century. The plan envisages actions to address the need

to mobilize international cooperation to improve knowl-

edge and innovation to address water security challenges;

to strengthen the science policy interface to reach water

security at local, regional and global levels; and to develop

institutional and human capacities for water security and

sustainability. Specific aspects of hydrology and human

needs are identified in the plan: water-related disasters

and hydrological changes; groundwater in a changing

environment; addressing water scarcity and quality;

water and human settlements of the future; ecohydrol-

ogy – engineering harmony for a sustainable world; and

education as a key to water security.

It is very clear that the Panta Rhei initiative of IAHS

and the 8th Phase of the IHP of UNESCO, commenc-

ing in 2014, not only overlap in timing but also, more

importantly, coincide in purpose. IHP has, from its

inception in 1975, recognized the importance of

understanding hydrological processes as fundamental

to underpinning water resources management. IAHS

has always worked very closely with IHP (and with the

complementary programmes of WMO and IAEA and

with many of the other organizations within UN-Water)

in a symbiotic relationship. IAHS and UNESCO work

closely with governments, with national and sub-

national institutions, and with individual scientists,

practitioners and policy makers. Cooperation of this

sort and the principle of working together is of great

benefit to society at large.

mentation. The fact that hydrology is relevant to society implies the

identification of societal needs for water – for the various water uses

– as well as the threats that water poses in terms of flooding, land

degradation and droughts. Here, we need a shift in paradigms of

modern water management based on equities between demand and

supply driven activities.

Panta Rhei recognizes the feedback between each of the three

targets: improved understanding may potentially lead to more accu-

rate predictions, which helps sustainable management. However,

management itself can contribute to the cycle of understanding.

The study of change in hydrological systems and society implies

fundamental science questions that in Panta Rhei have been delib-

erately kept few and concise. They have been formulated after an

extensive consultation with members of the hydrological and water

resources community. The major science questions are:

• What are the key gaps in our understanding of change?

• How do changes in hydrological systems interact with and affect

natural and social systems driven by hydrological processes?

• How to identify and represent the occurrence and drivers of

change in hydrological systems?

• How to improve knowledge of hydrological systems including

indeterminacy assessment for improving modelling, prediction

and uncertainty estimation?

• How can we advance our monitoring and data analysis

capabilities of hydrological processes?

• How can we support societies to adapt to changing conditions

by considering the uncertainties and feedback mechanisms

between natural and human-induced changes?

The science questions of Panta Rhei are rooted in the fundamental

concepts of hydrology and are focused on society and environmental

management. They propose a compelling synthesis between basic and

applied research.

The IAHS VIIth Scientific Assembly participants, Foz de Iguassu, Brazil, 2005

Image: IAHS

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