Summary from the 1st meeting of
Hydrology 2020 Working Group

The Hydrology 2020 working group met on January 23^rd, 2002 for a two and a half day workshop in Edinburgh, Scotland to discuss issues relevant to the future development of hydrology. Initiated by the IAHS and partially supported by UNESCO and the WMO, working group members Taikan Oki (committee chair) of Japan, Jeanna Balonishnikova of Russia, Wolfgang Diernhofer of Austria, Pierre Etchevers of France (absentee), Stewart Franks of Australia, Guobin Fu of China, Kate Heal of the UK, Susan Hubbard of the USA, Harouna Karambiri of Burkina Faso, Johan Kuylenstierna of Sweden, Stefan Uhlenbrook of Germany, and Caterina Valeo of Canada, met with Pierre Hubert, the IAHS General Secretary, to kick off the group's first meeting. For more information on the group and its individual members, please see http://www.cig.ensmp.fr/~iahs/hydrology2020/H2020WG.htm.

Dr. Hubert welcomed the committee and provided initial guidance to the group. While most of the members were nominated from the individual IAHS commissions, Dr. Hubert released any constraints and gave the group the freedom to develop their own guidelines, mandates, agenda and tasks; but with the primary goal of identifying possible and recommended directions for the field of Hydrology over the next 20 years. The meeting began with each member providing a brief overview of their research and perspectives. The committee demonstrated considerable breadth and depth covering many sub-fields of hydrology from global hydrological modelling to microscale estimates of hydrological parameters. The first meeting objective following the presentations was to determine the group's Mission Statement:

"We will explore how hydrological sciences can evolve into a discipline capable of meeting the world water challenges that are expected to prevail by 2020. We will undertake a broad range of tasks, from identifying knowledge gaps and hydrological research priorities to determining ways to improve communication between hydrological scientists and those involved with developing and implementing water policies. Our intention is to formulate a vision that will be embraced by practising hydrological scientists and will also persuade younger scientists to become involved in hydrological science research."

To address the Mission Statement, we began discussing key questions that the Mission Statement naturally invokes. One of the first is what are the world water issues, what will be demanded from society and how will the problems be solved? Increases in human population, urbanized areas, demand for food, development and energy consumption will result in ever escalating stresses on the hydrosphere. In general, the preservation of the world's water resources is vital to coping with anticipated land use and land cover changes, climatic changes, changes in hydrological cycles, provision of ecosystem services, hydrological extremes, deficits of clean fresh water in many regions of the world, and rising water conflicts between stakeholders in common areas and different countries. We need to build robustness and resiliency into our water resource systems.

It is recognized that water plays a key role in all environmental and societal issues, and hydrology is an interdisciplinary science involving ecologists, geologists, (geo)chemists, soil physicists, geophysicists, social scientists, atmospheric scientists, geotechnical and civil engineers, and geographers. But despite this multi-disciplinary nature, it is in itself a unique field with a number of distinguishing qualities. Unlike many other fields, it is believed that all hydrological research has some end use but its development rests on detailed fundamental physics. Hydrology, has been a science that has been successful at providing solutions without fully understanding all governing processes. Principal concepts that are unique to hydrology include hydrological cycles, the conversion of precipitation heights to river discharges; unsaturated flow; contaminated flow of ground water; statistics on the probability of exceedance; soil heterogeneity and the general measurement and modelling of water flow and water quality.

Over the past 20 years, the field of hydrology has seen a number of advances and obstacles. The previous two decades began after the Green Revolution, the concept of fractals, etc.. Several significant advances have occurred including: digital radar rainfall measurements and real time remote logging of field observations; the FIFE experiments; scaling issues; fuzzy computing, neural networks; chaos theory; Bayesian statistics; global warming issues and ENSO concerns. The key question is: How can hydrological science help mitigate the anticipated water crises in the world? To begin addressing this question, the Hydrology 2020 Working Group started identifying several key bottlenecks facing hydrology today. The issues ranged from technical gaps, communication barriers, and funding. As a preliminary working list, the following issues were identified as problem areas or research areas requiring more work.

1. Data problems: increased accuracy of spatial information; cuts in monitoring programs
2. Better use and understanding of satellite information and remote sensing.
3. Tracers: better methods and better understanding of residence times
4. Increased attention to field experiments: better development of experimental hydrology and a balance between modelling and field experiments is necessary.
5. Process understanding: understanding of variability and response to changes
6. Space-time patterns
7. Accuracy and uncertainty
8. Climate and hydrologic variability
9. Holistic, integrated models that involve coupled systems and appropriate feed-back mechanisms.
10. Scale Processes: scaling up or down and climatic impact assessments
11. Regionalization: hydrological data from non-monitored river basins and the transferability of models
12. Water productivity, mitigation and adaptation.
13. Soil characteristics and heterogeneity.
14. Hydro-ecology and understanding the responses of aquatic flora and fauna to changes in the water regime; dissolved particulate partitioning of substances, freshwater ecosystem research and better links between water quality and quantity issues.
15. Two-tier hydrological research: the lack of hydrological research institutes and the hydrological research environment of developing countries.
16. FUNDING: Development of general long-term research programmes; creation of national hydrological associations to coordinate research programmes and the appropriate allocation of substantial funds.

We feel that particular attention to the following areas can assist in addressing the above points:

Hydrological Data:

We need to combat the decline in monitoring networks and somehow increase availability and decrease cost. There needs to be a standardization of data quality and formats, increased research into the limitations and use of remote sensing (thermal, visible, microwave, radar) and a better understanding of data requirements in models with regard to scale.

Model Testing:

Greater research is required into the need for a robust physical basis, the need for calibration, calibration approaches, validation and verification, uncertainty estimation, and hypothesis testing.

Technology and Information Transfer:

Some of the expected technological and theoretical developments that may be expected to benefit hydrology include geomatics technology such as remote sensing, Geographic Information Systems and Global Positioning Systems. This technology can provide higher spatial, temporal, and spectral resolutions. In addition, finer resolution numerical modelling; improved data transmission, communication and visualization, bio- and nano-sensors, systems theory which can synthesize and integrate components more efficiently (industrial engineering) and uncertainty modelling are expected to provide greater advances. However, do we do enough to promote adoption of the "best" science and should we consider ourselves responsible for disseminating insights? Are we failing the less developed countries? Do new solutions filter through to practice and is there any value in standardized approaches? This leads to another issue dealing with the role of hydrological science in society.

It is evident that we are dealing with an "economically driven science" so who decides what is important? What is the role of scientist in affecting change? We believe that better communication and better relationships should be forged between the hydrological scientist/engineer and those that develop policy. This means that it is important to account for the policy impacts of new research results and this means breaking down the barriers to integrating hydrology with water resources management. We need to assist in satisfying the water demands of society, which means that hydrological science should service decision and policy makers. This means that we need increase social responsibility for scientists and researchers. To this end, we consider the role of education in hydrology. What should we tell people about hydrology? Education to all levels of the public should include both the natural and artificial hydrological cycles, hidden hydrological cycles, such as salty ground water intrusion, the state of the art of water resources and anticipated catastrophes of the world water crisis, the interactions between scales in time and space, the cause and effects manifested on local, regional, and global levels, and demonstrate that a long term view is necessary. In turn, we believe that society has a responsibility to the hydrological engineer and scientist. We need funding and recognition of excellent research.

As part of our Mission Statement we intend to provide information to a variety of groups including the IAHS, scientists, engineers, technicians, water managers, policy and decision makers, funding institutions, and the general public. The methods of disseminating this information will include an IAHS Red Book in 2005 (to provide specific recommendations); workshops, press articles, flyers, and newspapers articles. They will include information such as recommendations for action, summaries for policy makers and research priorities. The group will also be soliciting input and comments from others in the hydrological community both nationally and internationally.

The committee expects to produce a variety of outputs and to meet at least 2 more times in person but to correspond by email regularly. We will meet prior to the 6th Kovacs Colloquium in Paris in June, 2002, at the IUGG/IAHS assembly in 2003 in Sapporo, and again in 2004 and 2005.

Member tasks over the next six months include providing succinct reviews of knowledge gaps in ecohydrology and water quality; assessment and forecast of global water resources and their use; ground water; downscaling/impact assessments; snow hydrology; application of hydrology to water resources management; remote sensing; hydrology and SVAT models; runoff process and tracers; linkage between hydrology and policy making and how hydrological sciences contributes to the economy; international collaboration and erosion. The evaluation will be both critical of gaps and praising of milestones. Comments on the working group's mission statement and goals are welcome and may be submitted to taikan@iis.u-tokyo.ac.jp.

(drafted and edited by Caterina Valeo)

Hydrology 2020 Working Group
We are:

Jeanna BALONISHNIKOVA	Russia/Ukraine
Wolfgang DIERNHOFER	Austria
Pierre ETCHEVERS	France
Stewart FRANKS	Australia
Guobin FU	China
Kate HEAL	UK
Susan HUBBARD	USA
Harouna KARAMBIRI	Burkina Faso
Johan KUYLENSTIERNA	Sweden
Taikan OKI	Japan
Stephan UHLENBROOK	Germany
Caterina VALEO	Canada