GeoLog

hydrological sciences

Groundwater springs harbour hidden viruses

Groundwater springs harbour hidden viruses

In many parts of Sub-Saharan Africa, groundwater springs are a vital, precious source of water. They are also a reservoir of disease. Research presented at the European Geosciences Union General Assembly in Vienna reveals that groundwater reservoirs in Ghana, Tanzania and Uganda contain diverse communities of viruses – including those that present a risk to human health.

The work, carried out by IHE Delft in the Netherlands and a number of local universities, is the first to find such extensive virus communities in groundwater. Amongst the 25 virus families found were pox and herpes viruses, responsible for a number of skin infections. Papillomavirus, which causes several types of cancer, was also present in the water. And this is just a fraction of what’s likely to be out there – other methods are likely to reveal many more, scientists involved with the new research say.

According to the new findings, the reason for this plethora of pathogens is poor sanitation in areas where freshwater percolates down from the surface and recharges the groundwater supply. Here, the viruses persist for several years before being discharged at the surface.

The virus communities were identified by extracting DNA from the groundwater. This graphic shows how they enter the groundwater and the local population. Credit: IHE Delft

Better sanitation and safe water supplies are needed to address the issue, but there aren’t always enough resources to tackle both. In areas like Kampala (Uganda) as much as 60% of the population relies on groundwater as a source of water. Simply switching to another source is not an option – there are none available.

In Accra (Ghana) and Kampala – groundwater systems are quite confined, covering an area that closely matches the distribution of the community. This means you can use a local approach to groundwater management, and develop something that works well for the communities living there.

Hydrogeolologist Jan Willem Foppen and his team take time to learn from the community, identifying pathways for the future together – an approach called transition management. Each pathway leads to small interventions, that the team can learn from. “When you work with a community and co-create knowledge, you get beautiful and unexpected results,” says Foppen.

For Foppen, the enthusiasm of the local population towards this approach is one of the most rewarding parts of the job: “we see this being replicated in other communities in Ghana and in Kampala, that is the biggest compliment we can get.”

This is still much to uncover about these virus communities. For example, scientists don’t yet know whether the viruses are dead or alive. 70% of the DNA found in the springs was unidentifiable. What’s more there is a whole separate group of viruses – RNA viruses – that haven’t even been studied yet.

By Sara Mynott, EGU Press Assistant

Geosciences Column: Flooded by jargon

Geosciences Column: Flooded by jargon

When hydrologists and people of the general public use simple water-related words, are they actually saying the same thing? While many don’t consider words like flood, river and groundwater to be very technical terms, also known as jargon, water scientists and the general public can actually have pretty different definitions. This is what a team of researchers have discovered in recent study, and their results were published in EGU’s open access journal Hydrology and Earth System Sciences. In this post, Rolf Hut, an assistant professor at Delft University of Technology in the Netherlands and co-author of the study, blogs about his team’s findings.

On the television a scientist is interviewed, in a room with a massive collection of books:

“Due to climate change, the once in two years flood now reaches up to…”

“Flood?” interrupts my dad “We haven’t had a flood in fifteen years; how can they talk about a once in two years flood?”

The return period of floods is an often used example to illustrate how statistically illiterate ‘the general public’ is supposed to be. But maybe we shouldn’t focus on the phrase ‘once in two years’, but rather on the term ‘flood’. Because: does my dad know what that scientist, a colleague of mine, means when she says “flood”?

In water-science the words that experts use are the same words that people use in daily life. Words like ‘flood’, ‘dam’ or ‘river’. Because we have been using these words for our entire lives, we may not stop and think that, because of our training as water scientists, we may have a different definition than what people outside our field may have. When together with experts on science communication, I was writing a review paper about geoscience on television[1] when we got into the discussion “what is jargon?”. We quickly found out that within geoscience this is an open question.

Together with a team of Netherlands-based scientists, including part-time journalist and scientist Gemma Venhuizen and professor of science communication Ionica Smeets and assistant professor on soils Cathelijne Stoof and professor of statistics Casper Albers we decided to look for an answer to this question. We conducted a survey where we asked people what they thought words like ‘flood’ meant. People could pick from different definitions. Those definitions were not wrong per se, just different. One might be from Wikipedia and another from a policy document from EU officials. We did not want to test if people were correct, but rather if there was a difference in meaning attached to words between water scientists and lay people. For completeness, we also added picture questions where people had to pick the picture that best matched a certain word.

The results are in. We recently published our findings in the EGU journal Hydrology and Earth System Sciences[2] and will present them at the EGU General Assembly in April 2019 in Vienna. As it turns out: words like ‘groundwater’, ‘discharge’ and even ‘river’ have a large difference between the meaning lay-people have compared to water scientists. For the pictures however, people tend to agree more. The figure below shows the misfit distribution between lay people and water scientists: the bigger the misfit, the more people have different definitions. The numbers on the right are the Bayes factor: bigger than 10 indicates strong evidence that differences between lay people and water scientists are more likely than similarities. The words with an asterisk are the picture questions, showing that when communicating using pictures people are more likely to share the same definition.

Graph showing the posterior distribution of the misfit between laypeople and experts by using a Bayes factor (BF) for every term used in the survey. Pictorial questions are marked with an asterisk. A value of the BF <1∕10 is strong evidence towards H0: it is more likely that laypeople answer questions the same as experts than differently. A value of the BF >10 is strong evidence towards H1: differences are more likely than similarities. In addition to a Bayes factor for the significance of the difference, we also calculated the misfit: the strength of the difference. The misfit was calculated by a DIF score (differential item functioning), in which DIF =0 means perfect match, and DIF =1 means maximum difference. (Figure from https://doi.org/10.5194/hess-23-393-2019)

Maybe that scientist talking about floods on the television should have been filmed at a flood site, not in front of a pile of books.

Finally, the term ‘flood’ proved to be one of the words that we do tend to agree on, so maybe dad should take that class in basic statistics afterall…

By dr. ir. Rolf Hut, researcher at Delft University of Technology, the Netherlands

[This article is cross-posted on Rolf Hut’s personal site]

References

[1] Hut, R., Land-Zandstra, A. M., Smeets, I., and Stoof, C. R.: Geoscience on television: a review of science communication literature in the context of geosciences, Hydrol. Earth Syst. Sci., 20, 2507-2518, https://doi.org/10.5194/hess-20-2507-2016, 2016.

[2] Venhuizen, G. J., Hut, R., Albers, C., Stoof, C. R., and Smeets, I.: Flooded by jargon: how the interpretation of water-related terms differs between hydrology experts and the general audience, Hydrol. Earth Syst. Sci., 23, 393-403, https://doi.org/10.5194/hess-23-393-2019, 2019.

GeoTalk: Making their mark: how humans and rivers impact each other

GeoTalk: Making their mark: how humans and rivers impact each other

Geotalk is a regular feature highlighting early career researchers and their work. In this interview we speak to Serena Ceola, a hydrologist and assistant professor at the University of Bologna, Italy, who studies interactions between humans and river systems. At the upcoming General Assembly she will be recognised for her research contributions as the recipient of the 2019 Hydrological Sciences Division Outstanding Early Career Scientists Award.

Thanks for talking to us today! Could you introduce yourself and tell us a little more about your career path so far?

I was born in Padova, Italy, and studied environmental engineering at the University of Padova, from which I obtained a master’s degree in 2009. Since my bachelor’s studies, I was fascinated by hydrology: both my bachelor’s and master’s thesis dealt with the availability of river discharge, which is the amount of water flowing through a river channel.

Then, in 2009 I moved to Lausanne in Switzerland and I continued my studies with a PhD at the Laboratory of Ecohydrology of the École Polytechnique Fédérale de Lausanne (EPFL). My PhD thesis focused on the implications of river discharge availability on river ecosystems (namely algae and macroinvertebrates). Since 2013, I have been based at the University of Bologna, Italy, currently as a junior assistant professor. Now my main research project focuses on the relationship between river discharge availability and human activities, both at local and global scales.

Serena Ceola collecting benthic macroinvertebrates used for a small-scale flume experiment in Lunz-Am-See, Austria. (Photo Credits: Serena Ceola)

What got you interested in environmental engineering and hydrology? What brought you to study this particular field?

Studying environmental engineering was the perfect trade-off between being an engineer and focusing on environment sustainability and protection. During my studies I have developed a forma mentis that allows me to quantitatively solve (or try, at least) any issue. Since I was always fascinated by water, hydrology was my ideal choice. I must also say that my professors played a key role: their enthusiasm and passion overwhelmed me, involving me in such a fascinating subject.

At this year’s General Assembly, you will receive the Outstanding Early Career Scientists Award in the Hydrological Sciences Division for your contributions to understanding of the relationship between river environments and human activities. Could you tell us more about your research in this field and its importance?

River discharge has always been my main research focus. During the last 10 years, I had the unique opportunity to focus on the possible implications of river discharge .

Human activities, such as dam development, deforestation, agriculture, urbanization, etc. are known to affect how much flowing water is available to river ecosystems. In particular, I realised that no one before had conducted a quantitative analysis of how human-derived modifications to the natural flow of a river could possibly affect its environment.

Flume experimental facilities. (Photo Credits: Serena Ceola)

During my PhD, I performed an experiment by building small artificial rivers aimed at quantitatively estimating how

stream algae and macroinvertebrates respond to two flow regimes, one influenced by human activity and one unaffected. The unaffected river regime was naturally variable while the other was constant, like downstream a dam.

The experimental results were promising, thus allowing me to develop an analytical model capable of reproducing observed biological data in a real river network, also proving its applicability in presence of anthropogenic influence.

Hydrologic controls on basin-scale distribution of benthic invertebrates: study area and average habitat suitability values for a mayfly species. Image redrawn from Ceola et al., 2014, WRR, https://doi.org/10.1002/2013WR015112

When focusing on human activities, it is extremely important to estimate the interrelations between humans and waters. Here, I was lucky enough to start working with satellite data measuring the distribution of human population in space and time across the globe. By using satellite nightlight images, I analysed the spatial and temporal evolution of human presence close to streams and river. When considering extreme events like floods, I also had the opportunity to identify the regions most at risk for flood deaths and damage to infrastructure.

At the General Assembly, you plan to give a talk about working with global high-resolution datasets, such as nightlight data, to better understand how human and water systems affect each other. What are some of the possibilities made available through this kind of analysis? What doors does this research open, so to speak?

Working with global high-resolution datasets, and in particular with datasets covering several years, allows one to analyse and inspect how human processes and hydrological processes have evolved and interacted in time. This kind of analysis offers the opportunity to study how human pressure on river flows has changed over time and examine urbanization processes influenced for instance by proximity to rivers. This method also allows researchers to analyze how people move as a consequence of climatic conditions, such as extreme floods or droughts.

Spatial evolution of human presence close to stream and rivers by using satellite nightlight images. Image taken from Ceola et al., 2015, WRR, https://doi.org/10.1002/2015WR017482

Before I let you go, what are some of the biggest lessons you have learned so far as a researcher? What advice would you impart to aspiring scientists?

Based on my experience so far my first recommendation is “Be passionate!” Since you will spend a lot of time (days and nights) on a research project, it is fundamental that you love what you are doing. Although sometimes it is difficult and you cannot see any positive outcome, be bold and keep working on your ideas. Then, search for data to support your ideas and scientific achievements (although sometimes it is quite challenging and time-consuming!), but this proves that your research ideas are correct. Interact with colleagues, ask them if your ideas are reasonable and create your research network. Finally, work and collaborate with inspiring colleagues, who guide and support your research activities (I had and still have the pleasure to work with fantastic mentoring people)!

Interview by Olivia Trani, EGU Communications Officer

Imaggeo on Mondays: In-tents Icelandic sunset

Imaggeo on Mondays: In-tents Icelandic sunset

This photograph was taken at the campsite near lake Mỳvatn during a field trip to Iceland. Every year a group of students from Wageningen University travels from the Netherlands to Iceland for a weeklong excursion as part of a course on catchment hydrology. The aim of the trip is to provide students with real life examples of the processes they learned during their lectures.

After a rainy morning that day, tents and equipment were packed away as quickly as possible in order to escape the wetness. The drive took the group from the campsite in Höfn, at the foot of the Vatnajökull glacier in southeastern Iceland, along the coastal highway up north towards Myvatn. Iceland is famous for its raw and beautiful nature, with waterfalls seemingly around every corner and the imposing presence of the glaciers and volcanos in the distance.

Upon our arrival at the campsite in the evening, people begrudgingly noticed that the tents were still wet from the morning rain. The campsite was situated at the bottom of a formidable hill, which provided stunning views over the lake and landscape. Not wanting to sleep in a damp tent, a few students picked up their tents, dismantled them, went up the hill and let the evening breeze do the rest, all amid the backdrop of a stunning sunset. The desire for dry covers even outweighed the very real danger of being eaten alive by masses of midges, a known pest and hazard in these parts.

When camping there is always things that can go wrong. But for places like Iceland it is the only way to truly appreciate and experience the country’s stunning beauty and wilderness. Gazing up at the northern lights from your sleeping bag is a once-in-a-lifetime experience. While waking up in the middle of the night and having to put on boots and jacket to run to the bathroom is vexing, you might be rewarded with views of the top of the glacier that has been shrouded in clouds all day, making it seem like Zeus himself is taking a peek down from Mount Olympus to see what is going on. Iceland has to be experienced, not from a cosy hotel bed, but from a tent put up in the evening and taken down the next day. As Albert Einstein once said: “Look deep into nature, and then you will understand everything better”. Even if that means hiking up a hill and holding your tent up into the wind to dry.

By Maria Warter, PhD student at Cardiff University