About HEPEX

"Hydrological Ensemble Prediction EXperiment (HEPEX) – What lies ahead?"

Short report on HEPEX meeting in Bejing, China, October 22-24, 2012

New HEPEX Governance
Good-bye and Welcome, John Schaake!
John Schaake founded the HEPEX initiative in 2004 and has been a relentless promoter of HEPEX throughout the years. Without his energy and dedication, the initiative would not have developed into the enthusiastic research network we now have established. In August 2011, John Schaake resigned from HEPEX as chair—but not from supporting the initiative! Quite the contrary, as he is now dedicating his time to developing an ensemble based flood forecasting system for the City of New York—which is likely to become a dynamic test bed for HEPEX.
We thank John for the years of support, energy and ideas with which he has fueled HEPEX over the years and we are counting on many, fruitful discussions in the future.

It would be very difficult for anyone else but John to continue this in the same fashion. That’s why HEPEX in the future will be carried on three co-chair shoulders that represent operational hydrology, operational meteorology and applied research. The new co-chairs of HEPEX are



As chairs of HEPEX we will advise our colleagues on useful links to other researchers and facilitate exchange of results, ideas and possible collaborations within the HEPEX network. We also promote the work done within the network at various conferences and meetings and try to increase the outreach of our network, possibly integrating it or linking it up with other existing networks. This provides the research with an increased visibility, more collaborations and subsequently a good chance to increase the number of relevant publications. Although HEPEX is does not currently have a funding mechanism to support research, we will seek opportunity also for financial support.

In an open meeting on HEPEX during the last EGU Conference in April this year, HEPEX members agreed to the following mission statement: To demonstrate the added value of hydrological ensemble predictions (HEPS) for emergency management and water resources sectors to make decisions that have important consequences for economy, public health and safety.

There is no change in the principle aims of HEPEX. The key questions addressed are still:

• What adaptations are required for meteorological ensemble systems to be coupled with hydrological ensemble systems?
• How should the existing hydrological ensemble prediction systems be modified to account for all sources of uncertainty within a forecast?
• What is the best way for the user community to take advantage of ensemble forecasts and to make better decision based on them

New Organization of HEPEX
In the past, HEPEX efforts were oriented toward the development of testbeds. Testbeds were a vehicle to collect data, propose experiments and connect researchers in the sharing of ideas and data. HEPEX testbeds proved useful for adding a practical context for scientific questions that needed to be addressed to advance a skillful HEPS for a variety of operational needs. While they remain a useful pillar for HEPEX, the activities of the network are increasingly driven by more explicitly defined experiments that aim to compare techniques and approaches to improve accuracy and reliability of ensemble forecast systems.

HEPEX is now organised around six major themes:

1. 1. Input and pre-processing (chair: F. Pappenberger)
2. 2. Ensemble techniques (chair: F. Pappenberger)
3. 3. Data assimilation (chair: A. Wood)
4. 4. Post-processing (chair: A. Wood)
5. 5. Verification (chair: J. Thielen)
6. 6. Communication and use in decision making (chair: J. Thielen)

HEPEX themes are led by the chairs of HEPEX, who help to coordinate and encourage researchers to propose, define and conduct

• HEPEX experiments or establish
• HEPEX testbeds

Under the umbrella of one or several HEPEX themes. HEPEX experiments and testbeds may connect with several of the overarching HEPEX themes as can be seen in the diagram below. Anyone wishing to contribute to the HEPEX initiative can propose an experiment or testbed.

Meeting HEPEX Members
HEPEX is increasingly an international project that brings together hydrological and meteorological communities from around the globe interested in building research projects that focus on advancing probabilistic hydrologic forecast techniques. Click here to view current HEPEX members HEPEX encourages the community to communicate their research results in scientific workshops and conferences. Research related to HEPEX has been presented at EGU 2009, EGU 2010, EGU 2011
In 2012, emphasis is put on strengthening collaboration with Asian partners:

• The 2nd international workshop on data assimilation for operational hydrologic forecasting and water resources management, Incheon, Republic of Korea, September 2012. Deadline registration 1 June 2012
• The 2012 International Workshop on Hydrological Ensemble Prediction Experiment (HEPEX) will be held in Beijing, October 2012

Participation in HEPEX is open to anyone wishing to contribute to its objectives. Individuals interested in becoming involved in HEPEX can do so as a member of the HEPEX Science Steering Group, User Council, or an affiliated international organization, or through participation in the HEPEX projects and activities.

For more information click on the Contacs page.
Click on HEPEX Newsletter registration to join it.
Click here to see the current list of HEPEX Committees.