Hydrological forecasting at EGU 2018 – what not to miss next week!

The EGU 2018 Annual General Assembly will take place next week, from 8–13 April 2017 in Vienna as usual. The HEPEX community will be represented in many ways, and below you will find a quick guide to the most relevant sessions for hydrometeorological forecasters throughout the week. The sub-session on hydrological forecasting consists of 5 oral and poster sessions and 1 pico session. Get the EGU app now and tag the sessions!

The very first day will kick off with two very interesting sessions just after lunch, the sub-seasonal to climate, and after that the hydrometeorological forecasting session

13:30–15:00 / Room 2.15From sub-seasonal forecasting to climate projections: predicting hydrologic extremes and servicing water managers – Learn more about everything from seasonal to decadal predictions, reservoir and water resources management

15:30–17:00 / Room 2.15Ensemble hydro-meteorological forecasting and predictive uncertainty estimation – Grab a coffee and return to the same room for a very diverse session on forecasting and uncertainty estimation. Then make your way to the poster session for both sessions.

POSTER SESSION 17:30–19:00 / Hall A: Come to discuss with poster presenters for flash floods and ensemble forecasters and meet colleagues of the Hydrological forecasting sub-division.

On the second day, we dive into flash floods in the morning and the afternoon offers the very popular PICO session on operational forecasting and warning system for natural hazards:

08:30–10:00 / Room B: Flash floods and associated hydro-geomorphic processes: observation, modelling and warning – This session offers a number of highlighted talks, such as near real-time flash flood impact forecasting, validating impacts from insurance data and monitoring of ungauged catchments with photogrammetric methods

The  meeting of the Sub-Division on Hydrological Forecasting will be convened by MH Ramos, on Tue, 10 Apr, 10:30–12:00 / Room 2.83
It is open to everybody. Come and join us, notably if you want to meet colleagues or get more involved in the organization of sessions

13:30–17:00 / PICO spot A: Operational forecasting and warning systems for natural hazards: challenges and innovation – as last year, this interactive PICO session aims to bridge the gap between science and practice in operational forecasting for different water-related natural hazard

POSTER SESSION 17:30–19:00 / Hall A: The posters for the flash flood session is as always a good venue to discuss science and enjoy the hospitality

Wednesday is another packed day, with the session on droughts and water scarcity in the morning and games and statistical post-processing in the afternoon. Do not forget the HS division meeting at lunch!

08:30–12:00 / Room 2.44: Drought and water scarcity: monitoring, modelling and forecasting to improve hydro-meteorological risk management – the session includes everything from megadroughts in Chile to crop vulnerability in Kenya alongside presentations on new techniques to monitor and model droughts.

10.30-11.30 / Room L6: Towards forecasts and early warnings of natural hazards everywhere – for the Plinius Medal Lecture, Hannah Cloke will illustrate some of our recent successes, the best future opportunities and the critical challenges in forecasting and providing early warnings of natural hazards at the global scale.
The Division meeting for Hydrological Sciences (HS) will be convened by Elena Toth, on Wed, 11 Apr, 12:15–13:15 / Room B. It is the opportunity  to learn more about the way sessions related to Hydrological Sciences are organized at the EGU Assembly. You’re all welcome!

15:30–17:00 / Room 0.49: Advances in statistical post-processing for deterministic and ensemble forecasts – learn more about Bayesian post-processing techniques, post-processing of spatial extremes and proper scoring rules.

Other sessions that are of great interest:

13:30–15:00 / Room L7: Games for Geoscience – Learn how games can be a good way to promote science and practice! As you know, games has long been a part of HEPEX activities.

13:30–15:00 / Room L7: Coupled atmosphere-hydrological modeling for improved hydro-meteorological predictions – A very interesting session on coupled atmosphere-land experiments and effects of feedbacks.

POSTER SESSION  15:30 – 17:00 Hall X1  for the games and 17:30–19:00 Hall A for the droughts and Hall X4 for post-processing

Even though the hydrological forecasting sessions are already over, there are plenty of more interesting presentations to look forward to:

08:30–10:00 / Room 2.95: Advances in socio-hydrology, which attempt to better understand the dynamic interactions and feedbacks within diverse coupled human-water system

13:30–17:00 / Room C: History of hydrology – brush up on your hydrological history and learn more on hydrology in ancient Greece and India, and of course the history of HEPEX!

POSTER SESSION 17:30–19:00, will be in Hall A

Another tradition in Vienna: the HEPEX social gathering @ EGU. As in last year, it will be co-organized with partners of the IMPREX H2020 project. It will take place on Thursday evening at 8:30pm at the Restaurant Melker Stiftskeller (Schottengasse 3, A-1010 Wien). There is a limit of the number of places, so if you have not already booked, please do so via this form.

Last day of the EGU Assembly and again a full day of presentations:

08:30–17:00 / Room C: Hydrological extremes: from droughts to floods – Extreme events from floods to droughts and everything in between

13:30–17:00 / Room 0.49: Subseasonal-to-Seasonal (S2S) Prediction: meteorology and impactsa new session dedicated to understanding predictability of forecasts on the sub-seasonal to seasonal scale

POSTER SESSION 17:30–19:00, will be in Hall A for the hydrological extremes and HALL X5 for the S2S session

As you can see there is plenty to see and do in Vienna. See you there!

Posted in announcements-events, floods, forecast communication, forecast techniques, forecast users, meetings | Leave a comment

Calibrating hydrological model by river gender improves model skill

Contributed by Professor Flora Poil

Soon-to-be-published research funded by the international Hits-Sia-Ekoj research programme has shown that hydrological models can be significantly improved by using the link between river name and hydrological behaviour. Professor Poil explains:

“Anecdotally, the name of a river is often determined by its behaviour; a male river is more often turbulent, a female river more often stable. We wanted to investigate this link further.”

Genders of the main rivers in France. Source: Reddit/r/MapPorn 

All across our planet our watercourses have been assigned gender by our ancestors; from ‘Father Rhine’ to the Brahmaputra (Son of Brahma), and from La Dordogne to the Mekong (the mother of all rivers).

Following a year spent mapping river gender globally, Professor Poil’s team used river gender to determine catchment characteristics which were then used to inform setup and calibration of the HYDRO-LOOF distributed hydrological model. For a 5 year validation period they showed a 0104% improvement in skill compared to a control setup of the model.

This £142,018 ($412,018) interdisciplinary project on river gender science has strong implications for the hydrological forecasting community, as project researcher Dr Jo Key explains further:

“We believe that this research has significantly advanced the Prediction in Ungauged Basins research agenda. Using the river name as a guide, accurate models can be constructed without field visits and observations, therefore we could rapidly improve our forecasts at much reduced cost.”

Asked to comment on how this important finding relates to ensemble predictions, Professor Poil was remarkably coy:

“We all know which gender is known for being unpredictable. Let’s just say that this is something we can see in the ensemble spread. We’ve got some additional funding to look at this further, but I can’t say more at this stage”

This research will be published on the 1st of this month in the ‘Fluvial OrthOgonal Learning’ special issue of HESS.

Posted in April fools! | 3 Comments

HEPEX logo competition: reveal your inner artist!

contributed by Shaun Harrigan and Louise Arnal

We need your help! HEPEX (Hydrologic Ensemble Prediction EXperiment) needs a shiny new logo* and we think there is untapped artistic talent bursting to be free within the community, so we are running an online competition seeking the “next top logo”.

Established in 2004, the HEPEX mission is to demonstrate the added value of hydrological ensemble predictions for emergency management and water resources sectors to make decisions that have important consequences for the economy, public health and safety.

HEPEX is looking towards the next decade: better communication with the wider scientific community, practitioners and decision makers, as well as the public, has been identified as a key theme. We think this competition provides the perfect opportunity to engage the community to help us refresh the HEPEX online platform.

Competition guidelines and details

  • The logo* should reflect the essence of HEPEX
  • It will be used across all HEPEX online platforms (e.g., website, Twitter, Facebook, YouTube, LinkedIn)
  • It should be colour-blind friendly
  • Entries can be a polished vector graphics file or an image of a hand-drawn sketch (which can be made into professional logo based on the original design)
  • The word “HEPEX” doesn’t necessarily have to be written within the logo
  • Final logo copyright must be open by creative commons licence
  • Up to 3 entries per person
  • Deadline: Thursday 31 May 2018


Submit sketches, images, and vector graphics files by email to: blog@hepex.org

Voting, selection, and prize!

  • A vote will take place online and HEPEX-ers far and wide will be invited to vote for their favourite design (voting will close 1 week after deadline)
  • The top 3 logos with the most votes will go through for final judging by the HEPEX Chairs
  • The winner’s prize is the knowledge that their beautiful design will be the new face of HEPEX, and they will also receive a mug with their winning HEPEX logo printed (nice!)

Technical hint

If you do not have the expensive Adobe Illustrator programme, there are free and open source alternatives, e.g. GIMP image editor with many tutorials on YouTube.

What do we mean by a logo?

*A ‘logo‘: “a small graphic design that can be worked into a website banner or a letterhead; or printed on a button, sticker, a tshirt, etc.”  It doesn’t need to have a particular shape, e.g square, rectangular, circular – whatever you like!

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What are the challenges for HEPEX over the next decade?

The question sounds grand and may be a bit difficult to give a simple answer to, but that was the question put forward to the participants at the HEPEX workshop in Melbourne in February. HEPEX was founded as an initiative in 2004 with the goal of bringing the hydrological and meteorological communities to “demonstrate how to produce reliable …hydrological ensemble forecasts that can be used to assist the water resources sector to make decisions that have important consequences for the economy and for public health and safety“. The achievements in ensemble forecasting up until today have been discussed in workshops and blogs, and the success of implementing hydrological ensemble predictions is unquestionable — and HEPEX has clearly contributed. This success, however, prompts the question: has HEPEX fulfilled all of its goals, and if so should we disband the community and go our separate ways?

Top: Participants at the 2nd HEPEX workshop in Boulder, Colorado in 2005. Bottom: Participants at the 7th HEPEX workshop in Melbourne, Australia in 2018. The community is apparently growing.

What is the future of HEPEX?

The answer  to the posed questions is hopefully no — we still have a role to play. But the focus may need to shift from the technical implementation of operational systems towards the wider use and impact of hydrological ensembles. To help us answer this we took the opportunity to pick the brains of some of the sharpest researchers, forecasters and decision makers during the 2018 workshop . The goal was to gauge where the starting point of reformulating the role of HEPEX. The task was to discuss the question in small groups (4-5 people) and try to formulate 1-2 challenges for hydrometeorological ensemble predictions over the next decade. The groups were asked to formulate the challenges as specifically as possible so that they could be ideally be measurable. The groups were then asked to select a champion to pitch their idea in front of the rest of the workshop. Through the marvels of technology, the entire HEPEX assembly was then asked to rate each idea via their mobile phones, selecting from “A. Very interesting” to “E: Not interesting at all”. The votes were collated, and after translating the letters into numerical rankings from 1 to 5 (the higher the more interesting), we could quantify which ideas were received as extremely topical and important, and which received only lukewarm support.

Education, communication and dissemination

The most popular idea to emerge was “to produce a curriculum to help train the next generation of ensemble forecasters”, which reached an impressive average score of 4.6. Clearly there is a need to develop outreach and training material for the next generation scientists and forecasters and to make sure that ensemble techniques are embedded into graduate and post-graduate training. As a community we can help by developing training materials such as the Handbook and training material, but perhaps also aim to organize more training courses. Good examples include the short course in hydrological forecasting  organized last year at EGU, and the data assimilation workshop following the HEPEX Quebec City meeting in 2016.

The “Peak-box game” created by Massimiliano Zappa and Käthi Liechti. An example of training material downloadable from the HEPEX web site.

In places 2-6, all with a score above 4, were suggestions on improved communication to support better uptake of ensemble forecasts; a community toolbox of methods and techniques; a focus on risk-based decision making; user-friendly (event-based) verification measures; and better data in support of global hydrological modelling. Although the toolbox and better datasets are technical suggestions, the other three suggestions are focused on the users of our forecasts. Also just below (3.9) was a suggestion that HEPEX needs to better describe the value of ensemble forecasts. Collectively, these results implied that a lot more effort is needed at interface between developers and users.

But do not forget the data!

The other suggestions that were not as popular, but still had a score of >3, were dominated by recommendations revolving around data: big data, data assimilation for initial conditions, using new data sources and data-driven analysis. Other suggestions dealt with integrating and coupling forecasting systems, for example by running high-resolution inundation models forced by large-scale models, interating high resolution deterministic with ensemble predictions, or including local knowledge in the forecasts. Also there was also a suggestion for a forecast glossary (which supports the better communication theme).

Is HEPEX still needed?!

And so, returning to the question:  do we continue with the HEPEX mission? The answer is, thankfully, unequivocal:  YES … but we need to broaden our activities. We are already involved in a lot of work on communication, dissemination and education, but it is clear that these areas will have to be emphasized strongly in the next decade. The number of operational hydrological ensemble forecasting systems running today is impressive compared to a decade ago, and yet there is still an enormous opportunity for more systems and a lot of technical improvements (for example using new datasets and exploiting the ones we already have to improve our forecasts). However, the focus on our 6th topic in the science implementation plan, Communication and Decision Making needs to receive more attention.

The future users of hydrological ensemble forecasts need our guidance!

We welcome your thoughts!

This post was a short summary of the discussions held at the HEPEX 7th Workshop in Melbourne, Australia in February 2018.

Posted in meetings, opinion, science plan | 1 Comment

Bridging the gap between forecasters and operational hydrologists: an OzEWEX summer institute project

Contributed by Melanie Loveridge, Bex Dunn and Yiling Liu

How often do we assume that we understand the users’ needs, which may later be proven untrue? At the recent OzEWEX Australian Climate and Water Summer Institute – held in Canberra, Australia – we got the chance to bridge the gap between forecasters and operational hydrologists.

Fifteen of us were invited to the OzEWEX summer institute, which provides early career researchers the chance to see the current and emerging data and technologies in use within government departments. Following some initial intensive training, we were given the opportunity to use this technology in an innovative but practically useful way.

In the end, we landed a group of three to understand the forecast needs of river and storage operators. We felt that there are so many amazing datasets that it’s unnecessary to create more. Instead, we thought – how do we make existing data more useful to the people who are actually using it? What better way to do this, than going back to basics and defining our end users’ needs.

Discovery of user requirements was performed through an online survey. It was designed to gauge current usage and desirable additions or improvements, and capture associations with different demographics. To date we have received 29 responses throughout Australia – keeping in mind that there is only a small Australian population of river and storage operators. This was then supplemented by follow-up phone interviews and four focus groups.

Our operator’s responses to forecast information have given rise to some very interesting initial findings. Existing forecast information (provided primarily by the Bureau of Meteorology in Australia) is clearly valued, with 79% of users satisfied with the service. Most operators also believed that enhancements could be made to existing forecast information.

More effective communication is key!

Operators wanted to see three key areas of communication addressed. This consistently came up when speaking with operators, as they want to be better enabled to interpret hydro-meteorologic forecasts. Most critically being confidence in forecasts or prediction uncertainties.

Similarly, where multiple forecasts of the same hydro-meteorologic variable is available, they wanted to understand the differences between those estimates. This could also be addressed through an increased understanding of the skill or uncertainty of predictions.

Lastly, they wanted more information about the technique used to create the forecast. This finding was curious as information about the underlying techniques are all provided on the Bureau of Meteorology’s website. It might be more related to the level of understanding of the forecast methods, i.e. maybe it would be more appropriate to have simplified explanations with supporting media (videos, illustrations, etc.).

Additional nationally consistent forecasts.

Communication is often seen as the biggest challenge for operators, however, additional nationally consistent forecasts were sought after. Although already in existence, operators wanted improved reliability for 7-day forecasts and beyond.

One dataset that several operators were particularly passionate about getting is an irrigation demand forecast. Amongst other things, these forecasts can predict the volume of irrigated water required in a catchment, valley or irrigation district. These predictions prove crucial to driving water efficiencies where there is ferocious competition and demand for this valuable resource. Others forecasts included potential and actual evapotranspiration, soil moisture and reservoir levels.

Where to now?

Users are the experts of their own craft, so it is important to understand the goals from their perspective and not our own. These results have suggested that although some additional datasets would be useful, increased communication around existing forecasts is key to increasing user trust (for river and storage operators at least). While not always appropriate, we encourage researchers to engage with end users’ to really understand their genuine needs.

Work continues on this project. However, initial results have already been presented to the Australian Bureau of Meteorology in the hope for future development. Furthermore, we intend to present further conclusions at the forthcoming Hydrology and Water Resources Symposium in Melbourne, Australia.

Posted in case-studies, forecast communication, forecast users, meetings, water management | Leave a comment

Summary of the 2018 HEPEX ‘Breaking the Barriers’ Workshop, Melbourne Australia.

Contributed by David Robertson, James Bennett, QJ Wang, Daehyok Shin, Andy Wood, Maria-Helena Ramos, Ilias Pechlivanidis and Fredrik Wetterhall.

More than 120 HEPEXers from 15 countries descended on Melbourne, Australia, for three days of sunshine, science and applications at the 2018 HEPEX ‘Breaking the Barriers’ Workshop.

The meeting kicked off with a warm welcome from the local organizing team (James Bennett, QJ Wang, David Robertson and DH Shin) and a series of short talks recognizing the importance of water predictions and science, and from an elder of the Wurundjeri people, who stressed the long history of indigenous peoples living in balance with the land and water. The Workshop was supported by CSIRO, the University of Melbourne and the Bureau of Meteorology.

CSIRO’s James Bennett does the honors in opening up the meeting (left), and Uncle Ron Jones welcomes HEPEX to Wurundjeri country (right)

The participants had the opportunity to listen and interact during the 38 oral presentations (including 3 keynote speeches and 10 invited talks), and 40 posters, whilst the open discussion sessions allowed sharing of experiences and insights. Here, we only select and summarize a few out of the numerous high quality presentations.

Hannah Cloke’s keynote talk “Fly me to the moon” set the stage by reviewing the last decade of progress in flood forecasting for the UK and challenges in taking flood forecasts to a global scale. Hannah above all highlighted the need to ‘be brave’ in trying new approaches, which stayed in the minds of participants for the rest of the workshop.

Subsequent presentations on day one reported on projects assessing the quality of global and regional forecasts of flash floods, riverine flooding, drought and seasonal streamflow generated by land system models harnessing and compiling global impact databases to support verification. Florian Pappenberger highlighted that a greater focus on integrating the land surface as part of Earth System prediction is likely to be the key to extending prediction skill.

A healthy diversity of methods were showcased, including multi-model approaches and data assimilation to improve estimates of modeling and forecast uncertainty, the coupling of coarse land surface models (LSMs) to sub-grid routing and high-resolution hydrologic/hydraulic modeling, and the use of GPU-based computing for forecasting.

The second day of the meeting opened with a description of the EDgE Copernicus proof-of-concept, which is comparing the performance LSMs for seasonal to sub-seasonal (S2S) forecasting in Europe and contrasting skill arising from ESP versus GCM-based predictions. The focus pulled back to methodological questions related to downscaling, merging and pre-processing of weather and climate forecasts, investigating predictability at S2S scales, and highlighting the advancement of dynamical national systems in countries such as New Zealand and China.

Talks also delved into using radar-based rainfall and ensemble approaches to flash flood forecasting. Verification was also discussed, with talks showing new systems for meteorological forecast verification in Australia as well as challenging HEPEX’s hydrologists to think more carefully about what we verify, and how event performance may affect user confidence in forecasts and their effectiveness in motivating action.

The keynote talk of the day was a blockbuster, with Dasarath “Jaya” Jayasuriya, the Director of Public Safety for the Bureau of Meteorology, who dispensed rare wisdom on how forecasting fits within Australia’s national services for managing resources and risk, including insights into forecast-related objectives, mindsets and constraints from the producer side to the public user side. Among other topics, his comments on how BoM navigates the path of serving different users while promoting overall acceptance of forecasts (perhaps through hands on case studies that raise awareness in the field), were illuminating.

Healthy discussions over a healthy lunch: intense days of forecast discussions were balanced by plenty of socializing. The Twitter stream #hepex and the WhatsApp ‘HEPEX in Melbourne’ played a key role in keeping participants in Melbourne and from abroad connected.

HEPEX Day 3 began with a focus on S2S forecasts, with an SMHI effort characterizing predictability (through watershed initial conditions and climate) using collections of geophysical attributes, and work in the UK to understand and enhance climate / drought predictability through the incorporation of NAO variability. The conversation turned toward forecast product development and communication, highlighting the importance of co-development of forecast services with users (see also the SWICCA Copernicus proof-of-concept).

The day’s keynote speaker, Matthew Bethune of the Murray Darling Basin (MDB) Authority, provided a bracing real-world overview of the use of hydrologic models to support decision making in the MDB, highlighting the difficult challenges of making robust release decisions to supply customers at lead times (days to weeks) during which weather, climate and river conditions are highly uncertain. Among the methodological needs raised in the talk, the need to know how climate change may impact current methods for prediction was also raised.

The final talk session of the meeting shifted to examples of real-world predictions for operations, both in flood warning and in hydropower operations for several systems. These talks provide inspiring case studies for effective implementations of ensemble techniques for energy management, underscoring the sense that HEPEX-style forecasting is becoming a reality for groups ready to ‘be brave’ and make the effort to implement ensembles. In addition, the speakers described methodological experiments aimed at finding the best strategies, suggesting that many questions are still of interest. Ensemble research is not a solved problem!

The presentations made available by the authors can be downloaded from here.

Maria-Helena Ramos from Irstea (new Division President-elect of EGU Hydrological Sciences for 2019-2021) announced that she is stepping back from co-chairing HEPEX after 4 years of outstanding leadership and irresistible camaraderie. Ilias Pechlivanidis from SMHI now steps up to fill her shoes, bringing his energy, enthusiasm, and new ideas to help lead HEPEX forward.

HEPEX closed out the meeting with breakout groups, an interactive digital survey, and a closing discussion to take stock of where HEPEX should go. Many aims of HEPEX – including the operational adoption of ensemble hydrologic prediction for the benefit of society – have evolved from being a dream in 2004 to being realized operationally in a number of countries. What then are the key challenges HEPEX should pursue in the next 10 years?

The detailed results of this discussion will be summarized in a future blog, but for now it is clear that challenges do remain (particularly in continuing to communicate the value of ensemble systems), and also many opportunities. This will be an ongoing conversation, so start thinking and contributing – where should HEPEX focus its efforts, what are the big challenges, and how can you help make it happen?

HEPEXers touring the Bureau of Meteorology’s National Operations Centre, where overview of BoM services was presented and the daily weather briefing observed, and Melbourne Water’s Sugarloaf Reservoir, pump station and Winneke water treatment plant, where the challenges of delivering water in a highly variable climate were discussed.

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Melbourne HEPEX “Breaking the Barriers” convention – Twitter feed

This week, the HEPEX traveling circus will descend on Melbourne, home of the Bureau of Meteorology, the University of Melbourne, Monash University and the CSIRO. HEPEX-ers will be tweeting their way through the convention – and these Tweets will be assembled in below Twitter stream. Feel free to add your thoughts, ideas and observations – just make sure they’re summarized in 140 280 characters max – and don’t forget to include the #hepex tag!

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Forecasts of water variables – interview with Ilias Pechlivanidis

I can’t exactly remember the first time I met Ilias, but I can remember that every time we have the opportunity to sit together, we end up having great talks about hydrology, modelling and Greece (including its food/drink specialities and beautiful places to visit!).

Ilias is a senior hydrologist at the Swedish Meteorological and Hydrological Institute (SMHI) since 2012. He has broad experience in hydrological modelling and forecasting, and has been recently appointed Scientific leader of the theme “Forecasts of Water Variables” at SMHI’s R&D department.

I had the opportunity to ask him some questions about this new challenge and the future of hydrological forecasting for water managers:

Maria-Helena Ramos (MHR): What is the main focus of the research at SMHI on the forecasting of water variables?

Ilias Pechlivanidis (IP): I would firstly like to thank you, Maria-Helena, for giving me the opportunity to openly share our group’s vision with the broader HEPEX community. Hopefully this blog post will be useful to all friends and colleagues, and particularly inspire the young forecasters.

Going back to your question, I should say that as a service provider at the national, continental and very soon global scale, we produce forecasts of different water (quantity and quality) variables and indicators, such as discharge, soil moisture, groundwater levels, evapotranspiration, snow, sediments etc., at different timescales (at short to seasonal ranges) and hydro-climatic gradients. To ensure usefulness, these forecasts need to be unbiased, reliable and coherent.

We investigate all the components of the hydrological production chain (i.e. selection of meteorological forecasts, pre-processing, hydrological model(s) and setup, calibration and initialization, updating, and generation, evaluation and visualization/communication of forecasts), and evaluate and refine these components for understanding better the sources for predictability. Our efforts focus on identifying the key factors influencing the spatial and temporal variation in hydrological predictability and improving the communication methods bearing also in mind that the user needs are mostly local.

I also find important to note that SMHI is among the very few institutes that acts as a factory and a storage house of many data products, which are further used in our different multi-basin hydrological investigations at the large scale (see our HYPE hydrological model setups).

These spatially broad model applications require a constant interaction with users, in order to learn from their experience of applying our models at the local scale and better comprehend local processes within our work at national to global scales. Despite the challenges of producing and analyzing big data, I consider myself privileged to be given the opportunity to conduct comparative hydrological forecasting analyses and hence complementing the ‘deep’ knowledge from single catchment investigations.

MHR: SMHI has a strong focus on developing forecast products for end-users. In your opinion, is there a “science of hydrological forecasting” and is it currently in phase with operational developments for water (and related risks) management?

IP: Maybe I could say here that a nice lesson learnt working at SMHI’s services is that there is no ‘end-users’ but rather an endless chain of ‘users’.

Indeed, SMHI has been developing various products and services for different users; as an example here for the HEPEX interest, I would point:

  • the Swedish national demonstrator, including from short term to seasonal forecasts, climate predictions and many more,
  • the pan-European short-to-medium range hydrological forecasting service,
  • the pan-European seasonal forecasting demonstrator interface as a proof-of-concept for the Copernicus Climate Change Services (C3S).

I have found very intriguing the different level of understanding between users, and so each service should meet the unique user needs. Nevertheless there is always a continuous need for product and service evolution.

We have been acting as scientific knowledge purveyors incorporating robust new insights and successful outcomes from R&D projects into our products and services. Until recently efforts of the scientific community have been technical and numerical allowing a significant improvement of the services, yet setting unfortunately a knowledge gap between data providers and users.

Despite the deep SMHI in-house knowledge of user needs, application of social science on user engagement has allowed better communication of results and co-evolution of knowledge. We have therefore been investing on co-designing services, providing guidance on ways that our products can address problems at the local and regional scales, and also on ‘teach the teachers’ trainings to ensure that results are adequately communicated.

Another point here is that more and more institutes are nowadays developing similar products and services for different water-related sectors. Although scientific inter-comparisons are very important to improve our process understanding, I believe that different setups have strengths in capturing different aspects of reality; ‘useful information exists in each product/service, so one simply needs to extract it’. To produce the best product for our users, we are currently focusing on operationally implementing multi-model approaches, including different meteorological forecasting systems, pre-processing methods, and/or hydrological models, and further identifying best approaches for multi-model averaging.

MHR: If a young scientist wants to start a PhD thesis today on “forecasting water variables”, what would you suggest as a topic for a 3-year research work, for instance?

IP: As a member of the HEPEX community, I am not sure I could answer this question deterministically. I personally see a lot of potential in different topics, aiming to address fundamental scientific and operational challenges. Without being strict in my selection, I am generally inspired by 3 topics (as I support using 3 arguments in 3 sentences):

  1. Seamless hydrological forecasting; we need to understand how to better bridge between weather, seasonal forecasting and beyond for hydrological purposes, particularly nowadays that integration of available systems (setup for operating at different time horizons and for meeting different types of users) is computationally feasible.
  2. Assimilation of data to advance operational services at the large scale; given that in-situ observations are not usually available in an adequate spatio-temporal resolution, I see the need to explore new Earth Observation technologies and data provided in (near) real time to improve model initializations and hence forecasts.
  3. Hydrological forecasting from an impact perspective for better decision-making; we must bridge the gap between forecast experts and users, driven by the need for a better knowledge/integration of user needs, and highlighting the importance to consider new ways to communicate forecasts and their uncertainty.

MHR: Are there opportunities today for people willing to collaborate with your group?

IP: Absolutely. Our group has been participating in numerous national and international research (and consultancy) projects, with quite major funding coming from the European Commission. This has allowed us to build a strong network with other scientific groups, operational/research institutes, users, and SMEs. Researchers have also been visiting us to work on a targeted challenge. Post-doctoral researchers have also been significantly contributing to our success.

Taking this opportunity, I would kindly like to inform the HEPEX community that we are currently offering a Post-doc contract in the hydrological forecasting scientific theme. For more details please check here.

Thank you, Ilias, for this interview. We are looking forward to hearing more about your challenges and achievements in the future!

Posted in activities, forecast techniques, hydrologic models, interviews, operational systems | 2 Comments

HEPEX 2017 Year in Review

The Hepex Portal published 28 posts in 2017. Here below the year in review, with its highlights.

First of all, two important events for Hepex coming soon:

  • Just a few weeks more to submit your abstract(s) to EGU 2018 (deadline: 10 Jan 2018, 13:00 CET). You can check all sessions proposed under the Hydrological Forecasting sub-division in this Hepex post.
  • The 2018 Hepex Workshop in Melbourne (“Breaking the Barriers”) is coming soon, on 6-8 February 2018. An exciting and intense programme, with 44 oral presentations and 40 posters, is waiting for us. Online registration (no fees) is open until 20 Jan 2018 (check here).

And also blog posts on past events:

  • a post on the event “Ensemble Prediction: past, present and future”, which took place during the ECMWF’s Annual Seminar, from 11-14 September 2017, in Reading (UK), to celebrate 25 years of ensemble weather forecasts. Several interesting presentations made available here.
  • a post on the session “(Ir‑)relevant scales in hydrology: Which scales matter for water resources management?”, convened at this year’s EGU General Assembly 2017.
  • a post on the 15th session of the WMO’s Commission for Hydrology (CHy-15), held in Rome, 7-13 December 2016.
  • a post on the Fourth Pacific Meteorological Council (PMC) and Second Pacific Meteorological Ministers Meeting (PMMM), which was held in Honiara, Solomon Islands, from 14 to 17 August 2017.

Two quizzes and one competition for the readers in 2017:

Publications and more on science and operations:

The HESS special issue on “Sub-seasonal to seasonal hydrological forecasting“, organized after the Hepex workshop in Norrköping, Sweden, in 2015, has gathered 40 papers of excellent quality.

Seasonal forecasts were also the topic of two blog posts, with bias correction (How suitable is quantile mapping for post-processing GCM precipitation forecasts?) and operational systems (Meeting user needs for sub-seasonal streamflow forecasts in Australia) highlighted.

Users were central for two posts on flood forecasting and warning: Community of Users on Secure, Safe and Resilient Societies and Understanding public responses to flood warnings, for instance.

And something to think about concerning the future of ensemble prediction: bridging the gap between hyper-resolution and hydrologic ensemble prediction.

We also published opinions on meteorological prediction and keeping flood memories and historical marks of high waters.

Four new interviews were published in 2017:

All Hepex interviews (15 in total) can be found here.

And, of course, games and decision-making:

A decision making “serious-game”, the Shopkeepers Dilemma Game, and the optimal decision rule were explained by Micha Werner, and an interesting discussion on Risk aversion and decision making using ensemble forecasts was proposed by Marie-Amélie Boucher and Vincent Boucher.

You can also help Hepex to produce more games and teaching material: check here.

Hepex blog portal is running since April 2013: almost five years of a very original and rich content on hydrological forecasting

  • Many more posts and news can be found in our archives and throughout the Portal.
  • For 2018, we invite you all to contribute with your own blog posts (tips can be found here) and to support the organization of Hepex activities and workshops.

Happy holidays! The Portal will be back in 2018!

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History of Hydrology Wiki – Interview with Keith Beven

Have you seen the wiki “History of Hydrology“? It was created by Professor Keith Beven, Professor Emeritus in the Lancaster Environment Centre, in 2016, and we have recently interviewed him to learn more about it:

What was your motivation behind creating the “History of Hydrology Wiki”?

I have always been interested in the history of the hydrology and hydraulics, which is both long and interesting.

A lot of the early history was summarized in the book on the History of Hydrology, written by Asit K Biswas (North-Holland, 1971) but only up to the end of the 19th Century. There have been a few history studies since, including my own papers on Robert Horton in Journal of Hydrology and Hydrological Processes in 2004, but not a lot.

Both AGU and the International Association of Hydrogeologists have collected some video interviews with eminent hydrologists and hydrogeologists, but clearly there are now very many who we cannot now interview about their work and collaborations.

I remember realizing that I had once met Walter Langbein at a meeting, when he must have been close to retirement. He had worked with Robert Horton but, as a very young hydrologist at that time, I had not realized and certainly had not thought to ask about it. It would be a shame if the history just faded away.

So it is a project I have had in mind for some time, but it is not something that hydrologists are going to get much academic credit for. More of a project for someone who has retired, so I started the site when I took my pension (albeit that I have not exactly retired from research yet).

We have seen that a page was recently posted to Max Adam Kohler, a pioneer in hydrological forecasting. This area of hydrology has long been seen as an “operational” activity. Do you think hydrological forecasting can also be considered as “science” within hydrological sciences?

That is an interesting question (with a long history). Max Kohler, who died only last month at the age of 102, was influential in setting up hydrological forecasting in the US, but also working for the international community as Head of the Hydrological Division at WMO.

As in meteorology, we would want hydrological forecasts to be based on the best available science – but unlike meteorology, hydrological responses are very much dominated by the boundary conditions including catchment characteristics rather than the process representations. In particular in extreme flood events, we cannot be sure that we have a good idea of the volume of inputs from the raingauge and radar data available to the forecaster (and as yet numerical weather prediction cannot provide better estimates). And while we can be pretty sure of observations of water levels, there is a lot of uncertainty associated with estimates of the corresponding discharges. Thus, even the water balance equation may not be that useful in forecasting.

There are certainly cases where there is apparently more discharge than rainfall (and much less than expected when, in mountainous areas, valley bottom raingauges do not reflect that the precipitation falls as snow at higher elevations). Thus in these cases, until we have better data or NWP predictions, data assimilation can be more important as a way of getting improved forecasts  than improved process representations.

Thus in the Lancaster Flood Forecasting Methodology we use a nonlinear transform of the observed inputs, with a linear transfer function, coupled with a simple data assimilation algorithm to produce forecasts and their associated uncertainties. That does not mean that either the nonlinearity or transfer function should not be considered as scientific – see the hypothetico-inductive arguments in Peter Young’s  article in Water Resources Research, 2013.

If you search for ‘ensemble’ on the wiki then one only gets one hit to a reference, whilst there are 8 results when you check for ‘uncertainty’ – are there trends  or fashions one can observe through history?

I think you have to remember that all the biographies (with one exception who will be 100 years old next month) are of hydrologists who have already died, and that running ensembles of models has only been possible since the later part of the 20th Century (my own first Monte Carlo experiments were carried out in 1980 on a CDC “Mainframe” computer. There will certainly be more mention of both model ensembles and uncertainties in the biographies of those who have been active since then. I am sure that trends and fashions will be evident in the material as it accumulates. That, after all, is what constitutes the history of a subject area, especially when (as in hydrology) dramatic innovations occur only rarely.

Finally, how do you think the HEPEX community can contribute to the “History of Hydrology Wiki”?

As a Wiki site, anyone can register to add or edit material on the site (at the moment I am acting as the moderator for entries), or can send me material. There are templates on the site for the different types of entry which can be biographies, histories of experimental catchments, histories of hydrological institutions and details of historical hydrological textbooks (it is somewhat surprising how texts from the early 20th Century look similar to those of the early 21st Century).

I have also recently added a section on annotated papers about the history of hydrology. The hope is that the materials will provide both a record of our history and a starting point for anyone wanting to do more detailed studies. We particularly need entries from the non-English speaking world which is certainly under-represented as yet. There is no reason why entries should not be in another language (see for example the entry for Eugène Belgrand), but it would be good if an English summary can be provided, with a link to the original (see Pierre Cappus).

There will be a session at EGU in Vienna in 2018 convened Okke Batelaan, Roberto Ranzi, Laurent Pfister and myself. With this session we aim to stimulate the discussion on how we, as a community, develop a historical literacy and integrate this in teaching and research to enhance our science. We warmly invite your contributions that discuss how hydrological concepts have gradually evolved over time; how forgotten methods might have contemporary value; the value of historical datasets of experimental catchments and their management; remarkable contributions of scientists, institutes and organisations.   Contributions from the HEPEX Community would be welcome – including (why not) something on the origins and history of the HEPEX project. A more detailed description of the session and the link for abstract submission can be found here. The abstract submission deadline is 10 January 2018, 13:00 CET.

Thank you for this interview and thoughts.

We encourage all Hepex members to contribute to the wiki and EGU session. Sessions on Hydrological Forecasting (science and applications!) will also be held at EGU 2018 (see them in a previous post) and abstract submissions to them are also welcome.

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