A –Streams of Thought– contribution by Tim van Emmerik & Nilay Dogulu.
From 10 to 14 July, 2017, the Scientific Assembly of the International Association of Hydrological Sciences (IAHS) took place in Port Elizabeth, South Africa. For the first time, YHS organized a series of events for Early Career Scientists (ECSs) on the African continent. By combining social and scientific elements, the program was aimed at connecting ECSs from all around the world to each other, and to more established scientists.
Three main events were organized: (1) Meet the Expert: “Predictions in ungauged basins under change”, (2) How to write a paper session, and (3) Early Career Community Building Discussion Session. Below we provide a short summary of all events.
Meet the Expert: “Predictions in ungauged basins under change”
On the Sunday before the start of the conference, YHS kicked off with the Meet the Expert session. For this edition, we invited speakers to share their vision on “Predictions in ungauged basins under change”. Predictions in ungauged basins (PUB) has been the focus of the PUB decade of IAHS from 2003 to 2012. The PUB initiative aimed at reducing uncertainty in streamflow, sediment and water-quality predictions by deepening process understanding in hydrology. This is of special importance for data-scarce regions of e.g. Africa, where remote sensing and parsimonious approaches substitute intensive monitoring and detailed modelling. At the same time, these regions are subject to both environmental and societal change, which highlights the need to study feedbacks between hydrology and society under dynamic conditions. This is the focus of the current Panta Rhei scientific decade of IAHS (2013-2022). “Panta Rhei – Everything Flows” focuses on process understanding in changing hydrological systems, which is imperative to secure water resources and a sustainable development, particularly in semi-arid regions of Africa.
With both decades being of high relevance to the African context, this session aimed to discuss the current state of PUB and Panta Rhei and bridging the gap between them. The speakers (1) discussed the outcomes of the PUB decade and its challenges, specifically for data-scarce areas such as Southern Africa, (2) summarized the current state of the Panta Rhei decade, and identified important outcomes and challenges so far, and (3) addressed the connection between both hydrological decades and started the discussion on how to implement Panta Rhei in scarcely gauged and ungauged basins.
Predictions in ungauged basins (Thomas Skaugen)
In his talk, Thomas Skaugen (Norwegian Water Resources and Energy Directorate) shared his vision on the PUB decade. According to him, PUB is (still) the holy grail in hydrology. He praised that the PUB decade was a strong community effort, which is by itself already an achievement for the hydrological community. On his way to PUB, he realized that secrets of hydrology continued to be hidden somewhere in the mist. Why are some (well-known) models still not able to simulate measured runoff? Because “calibration parameters are evil!” They make it difficult to disentangle the integrated processes that make up the hydrological response. The way forward is to move from calibrating model parameters to estimating parameters independently from observed data. The more information you have, the better you can constrain your model. This is not only the key lesson for PUB, but also very useful for Panta Rhei. You can find the slides of Thomas Skaugen’s presentation here.
Panta Rhei: Predictions under change (Hubert Savenije)
Hubert Savenije (Delft University of Technology) made the direct connection between PUB and Pantha Rhei by discussing predictions under change. Ungauged basins are already challenging areas for hydrological modeling. But what can we do to make predictions in ungauged basins that are exposed to change? To answer this question five examples were given. The key in predictions in ungauged basins, with or without change, is using data available from space. First, landscape characteristics can already be estimated from globally available Digital Elevation Models for hydrological modeling. As the landscape determines the governing hydrological runoff processes, landscape-based hydrological modeling is a straightforward step that can be applied anywhere. Second, the root zone storage capacity can be estimated from remote sensing. Vegetation designs its root systems as engineers design reservoirs. The storage should be sufficient enough to survive a dry spell with a certain return period. By simply estimating precipitation and evaporation using remote sensing, the evaporation deficits can be used to estimate the required root zone storage, which highly correlates to modeled maximum root zone storage, for drier regions. Third, river rating can be estimated using Unmanned Arial Vehicles (UAVs). Fourth, soil moisture stress can be detected and estimated using remote sensing. By looking at the vegetation (with Normalized Difference Infrared Index or active microwave remote sensing), rather than the soil, an estimation of actual root zone soil moisture can be made, instead of surface soil moisture. Finally, storage-area curves of small reservoirs can be estimated from space, using gravity estimation missions such as GRACE. With the current availability of remote sensing products, no catchment is truly ungauged. We just need to think how to use these new data in a smart way. For slides of Hubert Savenije’s presentation click here.
Connecting PUB and Panta Rhei (Berit Arheimer)
Berit Arheimer (Swedish Meteorological and Hydrological Institute) highlighted the link between the two hydrological decades. One of the major outcomes of PUB was the “PUB book”, that focused on understanding catchment behavior and constraining parameters in single catchments with observations. It was argued that PUB happened during hydrological postmodernism, because “postmodernism is typically defined by an attitude of skepticism, irony or distrust”. Instead of seeing catchments as Newtonian systems, a shift was made towards seeing catchments as Darwinian coevolving systems. Understanding global change can be achieved by generalization through comparative studies at several places globally, rather than individual sites. The reason why we should have this focus now is because (1) water is a major driver for environmental and societal status, (2) we can, through open data, PUB techniques, and advanced (cloud) computing, and (3) we, as catchment modelers, are needed to combine bottom-up and top-down analysis. Berit Arheimer’s presentation can be found here.
All speakers shared an overall optimism about the Panta Rhei decade. From PUB we learned many new observation techniques and ways to constrain and simplify our models. For the future, we should focus on using available sources of new data in an even smarter way.
How to write a paper session
For this edition, Dominic Mazvimavi (University of the Western Cape) and Graham Jewitt (University of KwaZulu-Natal) shared their insights on best practices in paper writing and publishing. They provided suggestions both on the writing itself, and how to get it published.
Writing The most important thing is the title of your paper. Bad titles make it easy for editors to reject your paper immediately, so it’s worthwhile to think about this. Avoid too short or too long titles, or titles without any information.
▪An investigation of the hydrological responses of mountain catchments: A case study of the Jonkershoek River in the Western Cape Province of South Africa [too long!]
▪Hydrological responses of the Jonkershoek River [too short and meaningless]
▪Hydrological responses in mountain(ous Jonkershoek River) catchment
For the rest, the main advice was to write clear and concise. Be clear about the objectives of the paper, and be transparent about the methods. One of the most important annoyances is the (mis)use of symbols. In hydrology, we prefer to have symbols with a single letter, and if necessary with subscripts.
Getting it published There’s more than 40 journals that are related to water sciences or hydrology, so which one to choose? It very important to check out the objectives of each journal and its targeted readership. For fundamental science a different journal might be better than for water engineering related journals. Also, depending on whether your research is of regional or international interest, you might consider a more regional journal, or an international journal. A few more important tips that we should always keep in mind:
- Have your paper proof-read before submitting to a journal. Spelling and grammatical errors can in sometimes really annoy reviewers or editors, and it would be a waste if this is the reason for rejection.
- Never ignore reviewer’s comments
- Respect deadlines.
For the complete overview of the suggestions for this session, as well as from all previous editions, you can visit the YHS webpage.
Early Career Community Building Discussion Session
Science thrives when its community is strong. Since the current young scientists are the leaders to tomorrow, creating a community for young scientists is crucial. Various organizations and networks have recently started to connect young scientists early in their careers. During this session, participants shared examples of existing early career networks and leadership activities, and brainstorm about potential improvements for the (near) future. (A post summarizing the discussions will be soon online!)
It was the first time that ECS events were organized at IAHS Scientific Assembly, and it has been a great success. With 30 to 50 people attending the sessions, the activities lured in 15-20% of the total conference attendees! We really hope that everyone enjoyed it as much as we did, and we aim to have YHS being involved at IAHS conferences for many years to come.
About the authors
Tim van Emmerik (@TimVanEmmerik) is PhD student at the Water Resources Section, Delft University of Technology, the Netherlands, AGU Student Council Member, and co-founder of the Young Hydrologic Society (YHS). Nilay Dogulu (@DoguluNilay) is PhD student at the Middle East Technical University, Ankara (Turkey), is the current chair of YHS, and editor of the YHS -Streams of Thought- featured blog series. Correspondence to Tim van Emmerik (firstname.lastname@example.org).
We would like to thank the YHS Blog Editors as well as the organizers of the IAHS Scientific Assembly 2017.