WaterUnderground
WaterUnderground

WaterUnderground

Groundwater—the world’s largest freshwater store— is a life-sustaining resource that supplies water to billions of people, plays a central part in irrigated agriculture and influences the health of many ecosystems. Water Underground is a groundwater nerd blog written by a global collective of hydrogeologic researchers for water resource professionals, academics and anyone interested in groundwater, research, teaching and supervision. The blog, started by Tom Gleeson and managed by Xander Huggins, is the first blog hosted on both the EGU blogs and the AGU blogosphere.

Dowsing for interesting water science – what’s exciting at EGU 2019?

Dowsing for interesting water science – what’s exciting at EGU 2019?

Joint post by Sam Zipper (an EGU first-timer) and Anne Van Loon (an EGU veteran).


Every April, the European Geophysical Union (EGU) holds an annual meeting in Vienna. With thousands of presentations spread out over a full week, it can feel like you’re surrounded by a deluge of water-related options – particularly since the conference center is on an island!  To help narrow down the schedule! Here, we present a few water-related sessions and events each day that caught our attention. Feel free to suggest more highlights on Twitter (using #EGU19) or in the comments section!


Monday 8 April

Using R in Hydrology (SC1.44)

  • Short course 16:15-18:00.
  • This short course will cover R packages and tools for hydrology with both newcomers and experienced users in mind.

Innovative sensing techniques for water monitoring, modelling, and management: Satellites, gauges, and citizens (HS3.3).

  • Posters 16:15-18:00.
  • Curious about new approaches to hydrological science? This session features citizen science, crowdsourcing, and other new data collection techniques.

Plastics in the Hydrosphere: An urgent problem requiring global action


Tuesday 9 April

Nature-based solutions for hydrological extremes and water-resources management (HS5.1.2)

  • Posters 08:30-10:15Orals 10:45-12:30
  • Nature-based solutions are meant to be ‘living’ approaches to address water management challenges – this session will explore how they are used in both urban and rural areas.

HS Division meeting: If you want to know more about the organisation of the Hydrological Sciences Division of EGU (and you like free lunch) check this out!

Plinius Medal Lecture by Philip J. Ward: Global water risk dynamics


Wednesday 10 April

Large-sample hydrology: characterising and understanding hydrological diversity (HS2.5.2)

Sustainability and adaptive management of groundwater resources in a changing environment (HS8.2.1)

  • Posters 10:45-12:30, Orals 16:15-18:00.
  • This session features examples of groundwater sustainability (and challenges) all over the world, with a particular focus on Integrated Water Resources Management.

HS Division Outstanding ECS Lecture by Serena Ceola: Human-impacted rivers: new perspectives from global high-resolution monitoring

Geoscience Game Night (SCA1)


Thursday 11 April

How can Earth, Planetary, and Space scientists contribute to the UN SDGs? (ITS3.5)

  • PICOs 16:15-18:00.
  • Check out the fun PICO format – a combination of posters and talks – and help figure out what the role of earth science is in meeting the United Nations Sustainable Development Goals.

Urban groundwater: A strategic resource (HS8.2.7)

  • PICOs 10:45-12:30.
  • Urban groundwater is understudied relative to groundwater in agricultural areas – what do we know about urban groundwater, and what remains to be learned?

Henry Darcy Medal Lecture by Petra Döll: Understanding and communicating the global freshwater system


Friday 12 April

Innovative methods to facilitate open science and data analysis in hydrology (HS1.2.7)

  • PICOs 08:30-12:30
  • Learn about how you can make your science more open, whether you are an open science beginner or a long-time data sharer!

History of Hydrology (HS1.2.3)

Social Science methods for natural scientists (SC1.48)

  • Short course 14:00–15:45
  • This short course is for everyone who has some dealings with people in their research, such as stakeholders, citizen science, The aim of the session is to demystify Social Science and give practical tips & tricks.

Other Resources

Several other groups and blogs have also compiled water-relevant sessions. Make sure to check out their recommendations, as well!


Cover image source: https://cdn.pixabay.com/photo/2015/09/09/21/33/vienna-933500_960_720.jpg

 

Have you ever wondered if groundwater is connected to climate?

Have you ever wondered if groundwater is connected to climate?

Post by Tom Gleeson Assistant Professor in Civil Engineering at the University of Victoria.


‘Groundwater-surface water interactions’ has become standard hydrologic lexicon and a perennial favorite session title at various conferences… but how often do you hear the phrase ‘groundwater-climate interactions’?

A group of hydrologists, hydrogeologists, atmospheric scientists and geodesists that met in Taiwan this week would say ‘not enough!’ We met to discuss how groundwater, the slow-moving grandparent of the hydrologic cycle interacts with the atmosphere, the fast-moving toddler. The 2nd international workshop on Impacts of Groundwater in Earth system Models (IGEM), was a follow-up of a 2016 workshop in Paris in 2016 (and part of a the bilateral French-Taiwanese IGEM project).

Sessions were focused around a few themes:

  • Groundwater use and its impacts
  • Groundwater representation, assimilation and evaluation in climate models
  • Remote Sensing and in-situ observations on groundwater
  • Groundwater-climate interactions with a special focus on Nebraska

 

And in the afternoons we convened discussion groups focused on ‘groundwater representation in continental to global hydrologic models’ and ‘groundwater-climate interactions’ and arguably just as importantly we ate lots of great food including an awesome fusion dinner and dumplings at the famous Din Tai Fung.

I would love to say that we could provide you with a simple, robust answer to the leading question of how and where groundwater is connected to climate – a holy grail of Earth System science. But like all good questions, the answer at least right now is ‘a little bit in some places, and it depends how you look at it’. We discussed the first enticing but preliminary results of potential hotspots of groundwater-climate interactions, expounded on the importance to water sustainability and dissected vadose zone parameterizations in land surface models but the quest for this holy grail goes on… We plan to meet again in a few years in Saskatchewan and maybe have a few more answers. Do you want to join us on this holy grail quest, and maybe end up making ‘groundwater-climate interactions’ more standard lexicon?

P.S. Thanks to Min-Hui Lo and his group at National Taiwan University for the excellent hospitality and organization!

P.S.S. Just in case it goes viral, the term ‘baddest-ass model’ was first used by Jay Famiglietti (see below).

Celestial groundwater – the subsurface plumbing for extraterrestrial life support

Celestial groundwater – the subsurface plumbing for extraterrestrial life support

Post by Kevin Befus Assistant Professor in Civil and Architectural Engineering at the University of Wyoming.


Have you ever taken a walk on the beach during a lowering (ebbing) tide and see mini-rivers grow and create beautiful drainage patterns before your eyes? These short-lived groundwater seepage features (Fig. 1A) are tiny (and fast) analogs of how groundwater has shaped some parts of Mars! It appears that groundwater loosening sediments can lead to all sorts of scales of erosion on both Earth and Mars.

Figure 1. A) Beach drainage pattern on the order of 1 meter (Source: https://epod.usra.edu/blog/2017/01/beach-drainage.html), B) Martian “alcoves” suggesting groundwater seepage [1].

Mars is not currently a friendly place for water to exist at the surface or even the subsurface, but an abundance of photographic and topographic evidence point to there having been the right conditions for active groundwater flow on Mars.

But isn’t Mars too cold for liquid water? The answer is generally a strong yes for the past few billion years, but amazingly enough, there appears to have been some local places where groundwater discharged to the Martian surface and left behind telltale signs.

Because Mars is cold at its land surface (mean surface temperature of -50 C with daily swings from 0 C to -100 C) with a thinner atmosphere than Earth’s, water on the Martian surface can exist as ice (as in the polar ice cap), but sublimation and evaporation would quickly wick any water near the surface. So, liquid water on Mars needs both more pressure and a good bit of heat for mobile groundwater based on the phase diagram below (circle with M shows the present day Martian surface conditions).

Figure 2. Phase diagram showing average conditions at the planetary surface for Earth (E) near the triple point, and atmospheric conditions for the frozen Mars (M) and vapor-rich Venus (V). source: http://www1.lsbu.ac.uk/water/water_phase_diagram.html#intr2; License: https://creativecommons.org/licenses/by-nc-nd/2.0/uk/)

It turns out that the most expansive evidence of liquid groundwater on Mars comes from deep at the bottom of craters (…deeper than 5 km!), where the Martian geothermal gradient (~10 C/km [Michalski et al.2013]) heats up to the point where groundwater systems, probably made up of brines, can seep across the crater walls. Without the craters, the groundwater wouldn’t have anywhere to discharge, but extraterrestrial hydrogeologists (really based on the geomorphology, but using E.T. hydrogeology principles) have identified numerous craters with groundwater seepage erosional patterns (Figure 1). The question remains open on how connected the Martian “aquifers” could be, or if the craters represent only local flow systems.

With liquid groundwater transporting the chemical-rich waters from deeper geothermal areas, the conditions could be right for supporting a deep Martian biosphere. Buried in under the Martian ice, soil, and rock microbial life could have evolved in the subterranean shelter from cosmic radiation. Groundwater flow, potentially related to geothermal conditions, could then have served as the conveyor belt for energy-rich molecules to feed microbial life in the subsurface (and still could?).

So far, Earth is the only celestial body in our solar system with an active water-hydrologic cycle, making us the lucky green planet. But, there could be a methane-based hydrologic cycle on Titan with “methanifers” as methane aquifers! For more information on extraterrestrial hydrogeology, Baker et al. (2005) provides a great overview of the planetary, lunar, and exo-planetary potential for water and groundwater, loosely summarized in this table.

At the moment, Earthlings don’t know that much yet about the paleo-hydrologic processes on Mars. But with new boots…I mean wheels…on the ground in two water-focused locations, new clues could start rolling in on Martian groundwater. The recently-arrived InSight lander will probe the Martian subsurface by drilling 5 m deep and listen for acoustic signals for even more information on the interior of Mars. The next Mars Rover is scheduled to take flight in 2020 for the Jezero Crater, where a river delta could help unravel the water-life story of Mars. And could have some groundwater surprises! At only about 1 km deep, the focus in mainly on tracking down signs of life and unravelling surface hydrologic and erosional processes on Mars, but a long list of expected outcomes does show the mission will keep an eye out for evidence of groundwater activities. Keep your feet grounded, eyes in the sky, and visions of Martian groundwater flying high and drilling low!

References
[1] Malin, M. C., and K. S. Edgett (2000), Evidence for Recent Groundwater Seepage and Surface Runoff on Mars, Science, 288(5475), 2330–2335, doi:10.1126/science.288.5475.2330.
[2] Michalski, J. R., J. Cuadros, P. B. Niles, J. Parnell, A. Deanne Rogers, and S. P. Wright (2013), Groundwater activity on Mars and implications for a deep biosphere, Nat. Geosci., 6(2), 133–138, doi:10.1038/ngeo1706.
[3] Stofan, E. R. et al. (2007), The lakes of Titan, Nature, 445(7123), 61–64, doi:10.1038/nature05438.
[4] Baker, V. R., J. M. Dohm, A. G. Fairén, T. P. A. Ferré, J. C. Ferris, H. Miyamoto, and D. Schulze-Makuch (2005), Extraterrestrial hydrogeology, Hydrogeol. J., 13(1), 51–68, doi:10.1007/s10040-004-0433-2.
[5] Robinson, K. L., and G. J. Taylor (2014), Heterogeneous distribution of water in the Moon, Nat. Geosci., 7(6), 401–408, doi:10.1038/ngeo2173.
[6] Jurac, S., M. A. McGrath, R. E. Johnson, J. D. Richardson, V. M. Vasyliunas, and A. Eviatar (2002), Saturn: Search for a missing water source, Geophys. Res. Lett., 29(24), 25-1-25–4, doi:10.1029/2002GL015855.

Kevin Befus leads the groundwater hydrology group in the Civil and Architectural Engineering Department at the University of Wyoming. With his research group, he studies how groundwater systems respond to hydrologic conditions over glacial timescales and in mountainous and coastal environments.  You can follow along with Kevin’s research through any of the links below:

Personal Webpage | Twitter Research Group Page | UW Faculty Page

 

 

 

 

 


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Of Karst! – short episodes about karst

Of Karst! – short episodes about karst

Post by Andreas Hartmann Assistant Professor in Hydrological Modeling and Water Resources at the University of Freiburg.


Episode 4 – Karst Groundwater: quick and slow at the same time?

We often associate groundwater with large water storage and very slow water movement for instance compared to rivers. But is it possible that groundwater flow can be as quick as stream flow and, at the same aquifer, flow for several months or years before it is reaching the surface again? Of karst, it is possible! When chemical weathering is able dissolve carbonate rock, cracks and fissures may grow to a subsurface channel system that can take vast amounts of water flow (see Of Karst! – episode 2).

The schematic figure below shows how this affects water flow in a karst system. At the surface, water may flow for some distance (external runoff towards the recharge area or internal runoff within the recharge area), before it reaches a dissolution widened vertical crack or fissure. On its way, part of it may slowly infiltrate into the soil but the stronger the rainfall event, the more water will infiltrate quickly into cracks and fissures after being redistributed laterally. Consequently, slow and quick infiltration will be followed by slow and quick vertical flow through the vadose zone. The former through the carbonate rock matrix, the latter through the interconnected system of dissolution caves. Finally, recharge and groundwater flow take place, again quickly through the caves and slowly through the matrix.  When passing the system through the cave network, water can enter and leave the system within several hours. When taking the slow and diffuse path, the transit through the system may take months to years.

Because of this behavior, hydrogeologists often speak about the Duality of Karstic Groundwater Flow and storage, although it is known that there is a wide range of dynamics between quick flow through the caves and slow flow through the matrix and that lateral redistribution between the interconnected caves and the matrix takes place at almost every part of the system.

Figure 1: Schematic description of karstic groundwater flow and storage (Hartmann et al., 2014; modified)

A rather uncomfortable lesson on quick flow processes in karst was learned by a group of school students on a trip through a karstic cave in Thailand. Due to the quick recharge processes explained above, the groundwater tables could quickly rise blocking the return path of the group and resulting in a dramatic rescue mission:

In order to predict the impact of interplay of quick and slow karstic groundwater processes on cave water levels or water resources in general, karst-specific simulation models are necessary. If you are interested in those, follow the Water Underground blog’s postings and wait for Of Karst! Episode 5, which will introduce karstic groundwater modelling.


Andreas Hartmann is an Assistant Professor in Hydrological Modeling and Water Resources at the University of Freiburg. His primary field of interest is karst hydrology and hydrological modelling. Find out more at his personal webpage www.subsurface-heterogeneity.com  

Further reading: Hartmann, A., Goldscheider, N., Wagener, T., Lange, J., Weiler, M., 2014. Karst water resources in a changing world: Review of hydrological modeling approaches. Rev. Geophys. 52, 218–242. doi:10.1002/2013rg000443

 

 


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Water: underground source for billions could take more than a century to respond fully to climate change

Water: underground source for billions could take more than a century to respond fully to climate change

WaterUnderground post by Mark O. Cuthbert, Cardiff University; Kevin M. Befus, University of Wyoming, and Tom Gleeson, University of Victoria


Groundwater is the biggest store of accessible freshwater in the world, providing billions of people with water for drinking and crop irrigation. That’s all despite the fact that most will never see groundwater at its source – it’s stored naturally below ground within the Earth’s pores and cracks.

While climate change makes dramatic changes to weather and ecosystems on the surface, the impact on the world’s groundwater is likely to be delayed, representing a challenge for future generations.

Groundwater stores are replenished by rainfall at the surface in a process known as “recharge”. Unless intercepted by human-made pumps, this water eventually flows by gravity to “discharge” in streams, lakes, springs, wetlands and the ocean. A balance is naturally maintained between rates of groundwater recharge and discharge, and the amount of water stored underground.

Groundwater discharge provides consistent flows of freshwater to ecosystems, providing a reliable water source which helped early human societies survive and evolve.

When changes in climate or land use affect the rate of groundwater recharge, the depths of water tables and rates of groundwater discharge must also change to find a new balance.

Groundwater is critical to agriculture worldwide. Rungroj Youbang/Shutterstock

The time it takes for this new equilibrium to be found – known as the groundwater response time – ranges from months to tens of thousands of years, depending on the hydraulic properties of the subsurface and how connected groundwater is to changes at the land surface.

Estimates of response times for individual aquifers – the valuable stores of groundwater which humans exploit with pumps – have been made previously, but the global picture of how quickly or directly Earth’s groundwater will respond to climate change in the coming years and decades has been uncertain. To investigate this, we mapped the connection between groundwater and the land surface and how groundwater response time varies across the world.

The long memory of groundwater

We found that below approximately three quarters of the Earth’s surface, groundwater response times last over 100 years. Recharge happens unevenly around the world so this actually represents around half of the active groundwater flow on Earth.

This means that in these areas, any changes to recharge currently occurring due to climate change will only be fully realised in changes to groundwater levels and discharge to surface ecosystems more than 100 years in the future.

We also found that, in general, the driest places on Earth have longer groundwater response times than more humid areas, meaning that groundwater stores beneath deserts take longer to fully respond to changes in recharge.

Groundwater stores are ‘recharged’ by rainfall and ‘discharge’ into surface water bodies such as lakes. Studio BKK/Shutterstock. Edited by author.

In wetter areas where the water table is closer to the surface, groundwater tends to intersect the land surface more frequently, discharging to streams or lakes.

This means there are shorter distances between recharge and discharge areas helping groundwater stores come to equilibrium more quickly in wetter landscapes.

Hence, some groundwater systems in desert regions like the Sahara have response times of more than 10,000 years. Groundwater there is still responding to changes in the climate which occurred at the end of the last glacial period, when that region was much wetter.


Read MoreThe global race for groundwater speeds up to feed agriculture’s growing needs


In contrast, many low lying equatorial regions, such as the Amazon and Congo basins, have very short response times and will re-equilibrate on timescales of less than a decade, largely keeping pace with climate changes to the water cycle.

Geology also plays an important role in governing groundwater responses to climate variability. For example, the two most economically important aquifers in the UK are the limestone chalk and the Permo-Triassic sandstone.

Despite both being in the UK and existing in the same climate, they have distinctly different hydraulic properties and, therefore, groundwater response times. Chalk responds in months to years while the sandstone aquifers take years to centuries.

Global map of groundwater response times. Cuthbert et al. (2019)/Nature Climate Change, Author provided.

In comparison to surface water bodies such as rivers and lakes which respond very quickly and visibly to changes in climate, the hidden nature of groundwater means that these vast lag times are easily forgotten. Nevertheless, the slow pace of groundwater is very important for managing freshwater supplies.

The long response time of the UK’s Permo-Triassic sandstone aquifers means that they may provide excellent buffers during drought in the short term. Relying on groundwater from these aquifers may seem to have little impact on their associated streams and wetlands, but diminishing flows and less water could become more prevalent as time goes on.

This is important to remember when making decisions about what rates of groundwater abstraction are sustainable. Groundwater response times may be much longer than human lifetimes, let alone political and electoral cycles.The Conversation


Post written by:

Mark O. Cuthbert, Research Fellow & Lecturer in Groundwater Science, Cardiff University;

Mark Cuthbert is a Research Fellow and Lecturer in the School of Earth and Ocean Sciences, at Cardiff University in the United Kingdom. Mark’s work currently focuses on coupled hydrological-climate process dynamics in order to: understand groundwater sustainability; improve interpretations of terrestrial paleoclimate proxy archives;  and understand how Quaternary paleoenvironments influenced human evolution.

 

Kevin M. Befus, Assistant professor, University of Wyoming; 

Kevin Befus leads the groundwater hydrology group in the Civil and Architectural Engineering Department at the University of Wyoming. With his research group, he studies how groundwater systems respond to hydrologic conditions over glacial timescales and in mountainous and coastal environments.

 

 

Tom Gleeson, Associate professor, University of Victoria

Tom Gleeson leads the Groundwater Science and Sustainability group in the Civil Engineering Department at the University of Victoria.  His research interests include groundwater sustainability, mega-scale groundwater systems, groundwater recharge and discharge and fluid flow around geologic structures. Tom is also the founder of this blog, WaterUnderground.

 

 


This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Groundwater and drought

Groundwater and drought

Post by Andy Baker, Professor researching groundwater, caves, past climate, organic carbon and more at the University of New South Wales, in Australia.

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Drought is in the news here in New South Wales, Australia. But how are rainfall, drought and groundwater related?

First, we need to understand what drought is. Is it a water shortage? Or a lack of rainfall? Or something else? In the USA, the National Climatic Data Center define drought as the ‘absence of water’. They identify four types of drought: 1) meteorological drought (a lack of rainfall), 2) hydrological drought (a loss of surface water or groundwater supply), 3) agricultural drought (a water shortage leading to crop failure), and 4) socioeconomic drought (where demand for water exceeds availability).

Here in Australia, the Bureau of Meteorology defines drought as ‘a prolonged, abnormally dry period when the amount of available water is insufficient to meet our normal use’.  They add that ‘drought is not simply low rainfall; if it was, much of inland Australia would be in almost perpetual drought’. Much of inland Australia depends on surface and groundwater for their economy. If those regions experienced a groundwater drought, it would therefore be bad news.

Let’s look at New South Wales again. It covers both coastal regions, such as Sydney (where I am writing this), as well as a vast interior (where most of my research is based). The Bureau of Meteorology produces meteorological drought maps based on rainfall amounts over recent months. The current map shows large areas of New South Wales are experiencing rainfall totals that are in the lowest 10 percentile (‘serious’), lowest 5 percentile (‘severe’) and the lowest on record.

How does this deficiency in rainfall affect groundwater? And is there a groundwater drought? Long-term measurement of groundwater levels in boreholes (also called wells, depending on your country) can tell you whether water levels are rising or falling. Wells integrate groundwater recharge that comes from both surface water (e.g. rivers that lose water through their base) and from rainfall (also called diffuse recharge).

Real-time data of water levels from telemetered boreholes can provide timely information on groundwater drought (for example, here for NSW). Satellite products such as GRACE, which can infer groundwater levels from small changes in gravity over time, can provide large scale spatial coverage. Modelling products can calculate water balance from meteorological, soil and land use data.

The current Bureau of Meteorology map shows that deep soil moisture is very much below average across New South Wales. If we assume that deep soil moisture levels are only determined by rainfall recharge, then from this we would expect no rainfall recharge of groundwater to be occurring over large parts of New South Wales. From one location, Wellington, close to the middle of the drought region, we have the measured evidence from inside a cave that shows that rainfall recharge hasn’t occurred for 18 months (and counting).

Since 2011, forty loggers have been measuring the water percolating through the unsaturated zone of the limestone at a depth of 25 m at Wellington Caves. This winter, I did the latest download of the data. Or rather, the lack of data, as only four drip water sources were still active. Conditions in the cave are the driest since we started collecting data in 2011.

Drip rates have been on the decline since the winter of 2016. But note the decline temporarily slowed in 2017, starting in early April. That is the response to the last time there was rainfall recharge there – owing to almost 70 mm of rain falling over three days in late March 2017. Eighteen months ago.

In the inland of New South Wales, it is clear that in dryland farming regions, the lack of rainfall has now led to an agricultural drought. In contrast, latest available data from our groundwater monitoring networks shows that there is currently no decline in groundwater levels in the major irrigation districts, which is where river recharge occurs. But for our dryland farmers, and ecosystems that rely on rainfall recharge, the karst drip data show that the groundwater drought has hit. Australia is often called a country of drought and flooding rains. Flooding rains are what we need next so that we also have some river recharge to replenish our groundwater resource.

 

Wellington, NSW. July 2018. This is the UNSW Research Station, normally stocked and cropped, but not this year.

Groundwater and Education – Part two

Groundwater and Education – Part two

Post by Viviana Re, postdoctoral researcher at the University of Pavia (Università di Pavia), in Italy. You can follow Viviana on Twitter at @biralnas.

Part two of a two-part series on groundwater and education by Viviana.

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In my last post (“Drawing out groundwater (from the well)”) I wrote about the reasons why, as groundwater scientists, we should engage not only literally, when we collect groundwater samples to perform our research, but also metaphorically, such as raising awareness on the hidden component of the water cycle to stakeholders and civil society.

Education and capacity development can become more integrated in our work, in academia, if we emphasize and increase our attention given to finding the most effective way to train and motivate the new generations of hydrogeologists (e.g. Gleeson et al., 2012). Indeed, in a rapidly changing world where students have mostly unlimited access to information and tools, we cannot simply expect to adopt the “classical” teaching methods and be successful. Additionally, we certainly have to consider life long training of professionals to keep them up to date with respect to new information and contemporary issues (Re and Misstear, 2017).

Even more, I believe that our efforts should not be limited to education and training of groundwater scientists and professionals, but should also aim to bridge the famous gap between science and society.

This can involve a wide range of audiences and goals, but I think the following tips can apply to them all:

  • Consider shifting from a classical hydrogeological approach to a socio—hydrogeological one, particularly if your work entails assessing the impact of human activities on groundwater quality. Strengthening the connection with water end-users and well owners is fundamental to ensure an adequate knowledge transfer of our research results.

Picture 1: When sampling, do not forget to explain to well owners what you are doing and, most importantly, why you are there (photo by Chiara Tringali; Twitter @tringalichiara).

Picture 2: Interviews can be a precious moment for capacity building. If you can sit down with well owners and administer a semi structured interview, not only can you retrieve precious information and embed local know-how in your research, but also you can have time to disseminate results and discuss about the possible implementation of good practices to protect groundwater in the long run (photo by Chiara Tringali; Twitter @tringalichiara).

  • Engage with new media and social networks. It may seem like a waste of time, especially when productivity and “publish or perish” remain dogma in academia, but these are definitely the means everyone uses for communication nowadays. Not fully exploiting their potential can be make us miss a precious occasion for a direct interaction with stakeholders and the public.
  • Keep in mind that people are busy and we all get easily distracted. Try to use visual information as much as possible. Sometimes a short video, a nice picture or an informative graphic are more effective than a thousand words.
  • Improve your science communication skills. In a wold full of inputs, it is not sufficient to have something important to say. It, perhaps, matters more how you say it. For this reason, the time dedicated to learn how to speak in public, how to give an effective presentation (either if you are planning to give a talk in front of a technical audience or at a conference on vegetarianism) and how to write a press release is always well spent.
  • Share your passion. If you choose to work in hydrogeology or groundwater science, you are probably passionate about the environment and protecting our planet. Use these emotions to share your knowledge to civil society and learn how to adapt the content of your research to different audiences without trivializing it.

You can find more on this topic in the chapter Education and capacity development for groundwater resources management” (Re and Misstear, 2017) of the book Advances in Groundwater Governance (Edited by Villholth et al., 2017).

-Cover picture by Cindy Kauss (2018)

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Viviana Re is a post doctoral research fellow at the Department of Earth and Environmental Sciences of the University of Pavia (Italy). Her research interests are: isotope hydrogeology, groundwater quality monitoring and assessment, groundwater for international development.

She is currently working on the development and promotion of a new approach, called socio-hydrogeology, targeted to the effective incorporation of the social dimension into hydrogeochemical investigations.

Twitter: @biralnasPersonal website

How deep does groundwater go? Mining (dark) data from the depths

How deep does groundwater go? Mining (dark) data from the depths

Post by Kevin Befus, Assistant Professor at the College of Engineering and Applied Science at the University of Wyoming, in the United States.

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3D geologic data can be hard to come by, and can be even more difficult to combine into a continuous dataset. The cross-sections shown here are directly from 3D groundwater models that I compiled [Befus et al., 2017], primarily from USGS groundwater models, for the U.S. East Coast. I kept each of the regional domains (different color swaths on the map) separate, since I ran into the issue of “border discontinuities” between different models where naming conventions and hydrostratigraphic structure didn’t match up. Kh is the horizontal hydraulic conductivity.

We’ve all been asked (or do the asking), “where does your water come from?” This is a fundamental question for establishing a series of additional questions that can ultimately help define strategies for valuing and protecting a particular water resource.

For groundwater, we could phrase this question differently, and I often do when talking to well owners: How deep is your well? If I get an answer to this, then I can dive into additional questions that can help define more about the local groundwater resource: How deep is the well screen? How long is the screen? Do you know what the water level in the well is? Has it changed over some given time? Seasonally?

These are all useful questions, and they serve to begin establishing the hydraulic conditions of a particular aquifer. I ask these whenever I can.

To do this at a larger scale, we can turn to various governmental agencies that regulate groundwater resources and/or water well drilling and often collect and store groundwater data (e.g., www.waterqualitydata.us/, http://nlog.nl/en/data, http://gin.gw-info.net/service/api_ngwds:gin2/en/gin.html, or http://www.bgs.ac.uk/research/groundwater/datainfo/NWRA.html). There is a wealth of information out there internationally on wells when they were drilled and where the driller first hit water. These driller logs can provide a snapshot in time of the water table elevation and can be extremely useful for tracking hydrologic variability [Perrone and Jasechko, 2017], extracting hydraulic parameters [Bayless et al., 2017],  and for testing model results [Fan et al., 2013]. Unfortunately for us earthy nerds, some governments have restricted access to well installation data for either certain types of wells (i.e., municipal) or for all wells, usually for privacy or safety concerns.

Back to the original question. How deep is groundwater? I keep this question broad. We can usually answer this question for particular areas where we have access to the right data, but for large parts of the globe, and potentially underneath you right now, we cannot answer this question. The “right data” for a hydrogeologist is some form of information on geologic/stratigraphic layer (or lack of layering) that can be tied to the rock properties. For a surficial, unconfined aquifer, this can be relatively easy, but when we start stacking several geologic units on top of each other or start actually using the groundwater, this question of how deep groundwater is becomes tricky. We could qualify this question by asking how deep “usable” groundwater is, which, of course, depends on our definition of usable water for a specific purpose. Or, we can point (or integrate) through the Earth’s crust, core, and right back to its crust and calculate the huge value of how much water is “in the ground” (and minerals)[Bodnar et al., 2013]. And I haven’t even brought up porosity yet! Or specific storage!

A example of a great public 3D interactive web viewer (https://wateratlas.net/) that integrates groundwater data, geological information, and well construction details produced by the Centre for Coal Seam Gas at the University of Queensland (https://ccsg.centre.uq.edu.au/), which is supported by the University of Queensland and industry partners. For more information on this water atlas, please contact Dr. Sue Vink (s.vink@smi.uq.edu.au) or Alexandra Wolhuter (a.wolhuter@uq.edu.au).

Don’t worry. I won’t go there. I want to harass/encourage the hydro[geo]logic community to get serious about sharing their hydrogeologic data. This does mean metadata (do I hear a collective groan?), but metadata and data management plans are increasingly required to secure funding. CUAHSI’s Hydroshare site (www.hydroshare.org) provides a platform uploading hydro models, and the U.S. Geological Survey has developed a slick web system for exploring hydrogeologic models. But, I’d like to take this further, or at least get a service like that going for anyone who wants to share their models. There is a wealth of crustal structure data out there, and groundwater models are unique in often containing some representation of three-dimensional geology/hydrostratigraphy along with Earth properties. There are some great deterministic, published datasets and models of global hydrogeology [De Graaf et al., 2015; Huscroft et al., 2018], but we can do better. Wouldn’t it be great to have a centralized database to extract an ensemble of hydrogeologic structure used in previous regional or local studies? How about be able to draw a model boundary on a web interface and extract 3D structure for your next model? And compare cross-sections between models in the same area? Want to start fitting your puzzle pieces into the international hydrogeologic puzzle? The question now becomes, how do we do it? A “DigitalCrust” has been proposed [Fan et al., 2015], but is not yet in reach.

Join the movement of a “Digital Earth” [Gore, 1998]!

Here are some examples, initiatives, and free 3D [hydro]geology resources to get you started:

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Kevin Befus leads the groundwater hydrology group in the Civil and Architectural Engineering Department at the University of Wyoming. With his research group, he studies how groundwater systems respond to hydrologic conditions over glacial timescales and in mountainous and coastal environments.  You can follow along with Kevin’s research through any of the links below:

Personal WebpageTwitter Research Group Page | UW Faculty Page

 

 

 

 

 

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References

Bayless, E. R., L. D. Arihood, H. W. Reeves, B. J. S. Sperl, S. L. Qi, V. E. Stipe, and A. R. Bunch (2017), Maps and Grids of Hydrogeologic Information Created from Standardized Water-Well Driller’s Records of the Glaciated United States, U.S. Geol. Surv. Sci. Investig. Report2, 20155105, 34, doi:10.3133/sir20155105.

Befus, K. M., K. D. Kroeger, C. G. Smith, and P. W. Swarzenski (2017), The Magnitude and Origin of Groundwater Discharge to Eastern U.S. and Gulf of Mexico Coastal Waters, Geophys. Res. Lett., 44(20), 10,396-10,406, doi:10.1002/2017GL075238.

Bodnar, R. J., T. Azbej, S. P. Becker, C. Cannatelli, A. Fall, and M. J. Severs (2013), Whole Earth geohydrologic cycle, from the clouds to the core: The distribution of water in the dynamic Earth system, Geol. Soc. Am. Spec. Pap., 500, 431–461, doi:10.1130/2013.2500(13).

Fan, Y., H. Li, and G. Miguez-Macho (2013), Global patterns of groundwater table depth, Science, 339(6122), 940–943, doi:10.1126/science.1229881.

Fan, Y. et al. (2015), DigitalCrust – a 4D data system of material properties for transforming research on crustal fluid flow, Geofluids, 15(1–2), 372–379, doi:10.1111/gfl.12114.

Gore, A. (1998), The Digital Earth: Understanding our planet in the 21st Century, Aust. Surv., 43(2), 89–91, doi:10.1080/00050326.1998.10441850.

De Graaf, I. E. M., E. H. Sutanudjaja, L. P. H. Van Beek, and M. F. P. Bierkens (2015), A high-resolution global-scale groundwater model, Hydrol. Earth Syst. Sci., 19(2), 823–837, doi:10.5194/hess-19-823-2015.

Huscroft, J., T. Gleeson, J. Hartmann, and J. Börker (2018), Compiling and Mapping Global Permeability of the Unconsolidated and Consolidated Earth: GLobal HYdrogeology MaPS 2.0 (GLHYMPS 2.0), Geophys. Res. Lett., 45(4), 1897–1904, doi:10.1002/2017GL075860.

Perrone, D., and S. Jasechko (2017), Dry groundwater wells in the western United States, Environ. Res. Lett., 12(10), 104002, doi:10.1088/1748-9326/aa8ac0.

 

Data drought or data flood?

Data drought or data flood?

Post by Anne Van Loon, Lecturer in Physical Geography (Water sciences) at the University of Birmingham, in the United Kingdom.

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The basis for (almost) all scientific work, at least in the earth and environmental sciences, is DATA. We all need data to search for the answers to our questions. There are a number of options to get hold of data; we can measure stuff ourselves in the field or in the lab, generate model data, process data measured by satellites, or use data that other people collected. The last option has the advantage that you can cover much larger temporal and spatial scales than if you do all the measurements yourself, but it is not necessarily much easier or quicker. In this blog I do a quick and dirty tour of large-scale data collection initiatives in hydrology and introduce a new initiative focusing on groundwater drought.

“Hydrometeorological data…” (source: https://cloudtweaks.com/)

The classical way for hydrologists to use other people’s data (also called “secondary data”) is to use national-scale government-funded hydrometeorological databases such as the National River Flow Archive (NRFA, https://nrfa.ceh.ac.uk/) and National Groundwater Level Archive (NGLA, http://www.bgs.ac.uk/research/groundwater/datainfo/levels/ngla.html) in the UK and the US Geological Survey Water Data in the USA (https://water.usgs.gov/data/). This seems a good and reliable source for data, but there are worries, for example that the number of gauges worldwide is decreasing due to various reasons (Mishra & Coulibaly, 2009; https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2007RG000243; Hannah et al., 2011; https://onlinelibrary.wiley.com/doi/full/10.1002/hyp.7794) and that paper or microfilm archives are at risk (https://public.wmo.int/en/our-mandate/what-we-do/observations/data-rescue-and-archives). These national data are collated in global databases like the Global Runoff Data Centre (GRCD, http://www.bafg.de/GRDC/EN/Home/homepage_node.html) and the Global Groundwater Network (GGN, https://ggmn.un-igrac.org/), hosted by the International Groundwater Resources Assessment Centre (IGRAC). The problem there is that it is very dependent on the national hydrometeorological institutes to provide data, the records are not always up to date and quality checked, and important meta-data are not always available.

That is the reason that many researchers spend a lot of time combining and expanding these datasets. A few recent examples (NB: not at all an exhaustive list):

These are very helpful, but also quite time consuming for a single person (usually an early-career scientist) or a small group of people to compile and the dataset easily becomes outdated.

On the other side of the spectrum is crowd-sourced or citizen science data. This is already quite common in meteorology, both for weather observations (Weather Observations Website, WOW, http://wow.metoffice.gov.uk/), historic weather data (for example Weather Rescue, https://www.zooniverse.org/projects/edh/weather-rescue/) and climate model data (weather@home, https://www.climateprediction.net/, by Massey et al., 2014 https://rmets.onlinelibrary.wiley.com/doi/full/10.1002/qj.2455 ), but citizen science is starting to get used in hydrology as well. Some examples are (again not exhaustive):

Example of crowd-sourcing hydrological data via an App (source: http://www.crowdhydrology.com/)

Most of these are using citizens as passive data collectors with the scientists doing the analysis and interpretation. The nice thing is that it creates lots of data, but the downside is a lot of local knowledge is underused. There are, however, also initiatives that try to make use of this local knowledge, either from citizens themselves, from the experts in government agencies, or from local scientists who know much more about the local hydrological situation. Some of these are funded projects, such as:

Some of these are not funded, like the UNESCO NE-FRIEND Low flow and Drought group that produced an analysis of the 2015 streamflow drought in Europe after a community effort to collect streamflow data and drought characteristics from partners in countries around Europe (Laaha et al., 2017, https://www.hydrol-earth-syst-sci.net/21/3001/2017/hess-21-3001-2017.html). Or are only partly funded, for example by a COST action that only provides travel funding, as in the case of the FloodFreq initiative in which researchers collected a dataset of long streamflow records for Europe to study floods (Mediero et al. 2015, https://www.sciencedirect.com/science/article/pii/S0022169415004291) or the European Flood Database that could have been developed with support of an ERC Advanced Grant (Hall et al., 2015, https://www.proc-iahs.net/370/89/2015/piahs-370-89-2015.html).

The databases developed in funded projects are great because there is (researcher) time to develop something new. But it is also hard to maintain the database when the project funding stops and a permanent host then needs to be found. Unfunded projects can benefit from the enthusiasm and commitment of their collaborators, but have to rely on people spending time to provide data and be involved in the analysis and interpretation. These work best if they are rooted in active scientific communities or networks. I already mentioned the NE-FRIEND Low flow and Drought group (http://ne-friend.bafg.de/servlet/is/7402/), which developed into a nice group of scientific FRIENDs, but also organisations like the International Association of Hydrological Sciences (IAHS, https://iahs.info/) and the International Association of Hydrogeologists (IAH, https://iah.org/) play an important role (see Bonnell et al. 2006 – HELPing FRIENDs in PUBs; https://onlinelibrary.wiley.com/doi/full/10.1002/hyp.6196 ). IAHS for example drives the Panta Rhei decade on Change in Hydrology and Society (https://iahs.info/Commissions–W-Groups/Working-Groups/Panta-Rhei.do), which has a number of very active working groups that are driving data sharing initiatives. Another very successful example is HEPEX (https://hepex.irstea.fr/), which is a true bottom-up network with “friendly people who are full of energy” (https://hepex.irstea.fr/hepex-highlights-egu-2018/). These international networks can provide the framework for data sharing initiatives.

The value of international scientific networks for data sharing (source: https://hepex.irstea.fr/)

It also helps if there is one (funded) person driving the data collection and if there is a clear aim or research question that everyone involved is interested in. Also, a clear procedure and format for the data helps. With that in mind, portals have been developed specifically for data sharing in hydrology, for example:

– SWITCH-ON that focusses on open data and virtual laboratories where people can do collective experiments (http://www.water-switch-on.eu/project_pages/index.html).

– Hydroshare, which is a collaborative website where people can upload hydrological data and models (https://www.hydroshare.org/)

The most inclusive are the initiatives (either funded or unfunded) that manage to incorporate local knowledge, so those that do not only collect data, but also work with the data providers for the interpretation of the data. This synthesis aspect is the main strength of these initiatives and a lot can be learned by bringing data and knowledges together, even if no new data is created.

In a NEW initiative we are hoping to combine some of the advantages of the above-mentioned data collection efforts. The Groundwater Drought Initiative (GDI, http://www.bgs.ac.uk/research/groundwater/waterResources/groundwaterDroughtInitiative/home.html) is a three-year initiative starting in April 2018 that aims to develop and support a network of European researchers and stakeholders with an interest in regional- to continental-scale groundwater droughts. Through the GDI network we will collect groundwater level data and groundwater drought impact information for Europe. This is needed because most of the data collection initiatives mentioned above are focussed on floods, not on drought, and most collate data on streamflow, not on groundwater. Since around 65% of the Europe’s drinking water supply is obtained from groundwater and drought is (and will increasingly be) a threat to water security in Europe, it is essential to get a good understanding of groundwater drought and its impacts. Since groundwater drought is typically large-scale and transboundary, data on a pan-European scale is needed to increase this understanding.

The GDI initiative is embedded in the NE-FRIEND Low flow and Drought group and has obtained a bit of funding from the UK Research Council for workshops and some researcher time, but we hope to arouse the interest and the enthusiasm of even more scientists and government employees of various nationalities and regions to be involved in the initiative and to contribute with data, meta-data, local knowledge and interpretation of data. In return the GDI will provide tools to visualise and analyse groundwater droughts, a regional- to continental-scale context of the groundwater drought information, insights into the impacts of major groundwater droughts, access to a network of international groundwater drought researchers and managers, and the opportunity to participate in joint scientific publications. The long-term sustainability of the initiative will hopefully be developed through the network that we will establish and through the link with formal organisations like the European Drought Centre (EDC, http://europeandroughtcentre.com/) and IGRAC (https://www.un-igrac.org/ ), where the groundwater drought data will be stored after the end of the funded project.

If you are interested, please get in touch:

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Anne Van Loon is a catchment hydrologist and hydrogeologist working on drought. She studies the relationship between climate, landscape/ geology, and hydrological extremes and its variation around the world. She is especially interested in the influence of storage in groundwater, human activities, and cold conditions (snow and glaciers) on the development of drought.

Bio taken from Anne’s University of Birmingham page.

Socio-hydrology meets Broadway: Can we survive drought if we stop using the toilet?

Socio-hydrology meets Broadway: Can we survive drought if we stop using the toilet?

Post by Samuel Zipper, postdoctoral fellow at both McGill University and the University of Victoria, in Canada. You can follow Sam on Twitter at @ZipperSam.

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How can society best cope with water scarcity?

With Cape Town on the verge of being the first major city to run out of water (a topic for a future post here on Water Underground), this is a question on the minds of many water managers and scientists within the emerging fields of socio-hydrology and socio-hydrogeology.

Low levels in Cape Town, South Africa’s reservoir system. Image source: University of Cape Town News.

Recently, my wife & I had the opportunity to see a more musical exploration of this question at the Langham Court Theatre’s production of Urinetown here in Victoria. This satirical musical envisions a future in which severe droughts have limited water supplies to the point that government (controlled by a corporation) decides the best way to conserve water is to charge people to use the restroom, thus limiting both direct and indirect human consumption (by people drinking less and flushing the toilet less, respectively).

As a scientist, I naturally found myself wondering: how effective would this tactic be?

Fortunately, the data exist to give us at least a rough approximation. Globally, only about 10% of water is used in households; the vast majority (about 70%) goes to agriculture. Once the water reaches your household, however, Urinetown may have a point; in an average US household, toilets are the largest water user, averaging ~1/4 of domestic water use (33 gallons per household per day). Since the US has among the largest per-capita water use of any country, we can use this number as an upper bound for a back-of-envelope calculations: globally, if we collectively stopped flushing toilets today, we’d reduce water use by a maximum of 2.5%.

In contrast, switching to diets with less animal protein (particularly beef) can have a far greater impact, saving well over 10% – it takes 660 gallons of water to make a burger, equivalent to about 180 flushes of a standard toilet (see the water footprint of various foods here). However, water is inherently a local issue – most of the water that goes into your burger was used to grow crops, potentially far away from wherever you live, and does not consume local water resources. Also, the numbers we used for the above calculations have a lot of local variability, with up to ~1/3 of total water use in Europe and Central Asia in the household.

Percentage of indoor water use by different fixtures. Source: Water Research Foundation.

So overall, does the math add up for Urinetown? At a global scale, reducing agricultural water use through improvement in irrigation practices and changes in diet is going to have a much bigger impact. Locally, however, toilets do use a lot of water and restricting their use during times of crisis is a smart approach – and Cape Town has had an “If it’s yellow, let it mellow” recommendation since September. Replacing your toilet with a high-efficiency fixture can help as well – many cities and states have rebate programs to help reduce the costs of this switch.

And how does it turn out for the residents of Urinetown? To answer that question, you’ll have to see the show yourself. Urinetown had a three year run on Broadway, including winning three Tony Awards, and is now a popular choice for theatres all around the world.

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Sam Zipper is an ecohydrologist. His main research focuses broadly on interactions between vegetation and the water cycle, with a particular interest in unintended or indirect impacts of land use change on ecosystems resulting from altered surface and subsurface hydrological flowpaths. You can find out more about Sam by going to his webpage at: samzipper.weebly.com.