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Groundwater

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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The true meaning of life … for a hydrogeologist

I am currently on sabbatical with Thorsten Wagener’s group at the University of Bristol. While on campus, I stumbled upon this quote from Nelson Henderson (a farmer from Manitoba).  It encapsulates what I have been thinking about groundwater sustainability for a number of years: “The true meaning of life is to plant trees, under whose shade you do not expect to sit”. For me, as a hydrogeologist, I would re-write it to be something like: “The true meaning of life is to protect recharge and flow in an aquifer, from which you do not expect to pump.

Take a look at the original plaque and my doctored, groundwater-centric version. You never know, groundwater sustainability may just become the next fad in the inspirational quote universe …

Unconventional Oil and Gas Development and Groundwater – Comparing the English and Canadian Experiences

Unconventional Oil and Gas Development and Groundwater – Comparing the English and Canadian Experiences

by Grant Ferguson1 and Sian Loveless2

  1. Department of Civil, Geological and Environmental Engineering, University of Saskatchewan
  2. British Geological Survey, Cardiff, Wales

 

The differences between the English* and Canadian experiences of unconventional hydrocarbon development were apparent at a meeting co-hosted by the British Geological Survey, Geological Society of London and IAH in London in July 2018.

Attendees at the Use of the Deep Subsurface in the UK conference in July 2018 (Photograph by Barnaby Harding).

England has been in the exploration stage of shale gas since 2008 and, to date, only a handful of wells have been drilled and the first horizontal test frack began in Lancashire in October 2018. In contrast, in Saskatchewan, Canada, which is home of the northern portion of the Bakken play, over 250,000 oil and gas wells have been drilled since the 1950s.

Population density is low northwestern North Dakota and southeastern Saskatchewan, but satellite imagery shows light from oil and gas development in the Bakken Formation (from NASA Earth Observatory).

What are the reasons for such a stark contrast? In both cases hydrocarbon rights are predominantly owned centrally, by either the Province (80%) or the Crown and licensed through the UK Government. Recent mapping and a series of reports  by the BGS has suggested some potential for a range of hydrocarbons, including unconventional resources. However, an in-depth review process to be able to drill and test an exploration well in England may take years, owing to the multiple agencies and authorities involved in the decision making (Whitton, et al., 2017) and may encounter considerable controversy. There have been similar concerns about oil and gas development in Canada, which are highlighted by a review by the Canadian Council of Academies (Cherry et al., 2014). However, this has happened following decades of oil and gas production and has not impeded development in western Canada. In Saskatchewan, production wells are typically permitted within a matter of a few weeks and there are rarely comments from the public. In addition, population density is vastly different; England had a population density of 401 people per square km in 2010 (link) versus less than 4 people per square km in Saskatchewan (link). However, the conference highlighted that other, hydrogeological and geological factors may also be important, and the state of hydrogeological knowledge is a key factor.

Data from oil and gas wells drilled in Saskatchewan, such as stratigraphy, volumes of produced fluids and fluid chemistry is available to the public after a short confidentiality period. This has allowed for mapping of the subsurface and hydrogeological analyses over many parts of the region. Few impacts to groundwater have been documented, although monitoring is relatively sparse in Saskatchewan with only 70 monitoring wells over an area of 651,900 km², roughly twice the size of the UK. The majority of documented contamination incidents associated with oil and gas production are surface spills of either oil or produced waters. Flowback and produced waters are typically injected back into the subsurface.  Strata used for disposal have been well characterized in most areas due to exploration and production activities by the oil and gas industry. There is some uncertainty about the long-term fate of injected fluids.

The biggest unknown in Saskatchewan and many other areas with extensive histories of oil and gas production is the nature of the intermediate zone.  This interval, which is situated between the deepest aquifer capable of supplying potable water and the oil and gas producing zone, is typically data-poor because of a lack of investigation and monitoring.  Base of groundwater protection mapping has not been done comprehensively for most of Saskatchewan. However, the presence of thick Cretaceous shales are thought to provide adequate hydraulic separation between oil and gas producing zones and overlying fresh groundwater supplies. Large scale faults are uncommon in Saskatchewan, aside from collapse features related to the dissolution of the Prairie Evaporite. The most likely pathway for contaminants to reach the surface in most cases is through poorly completed or abandoned wells. Leakage of methane through wells appears to be fairly common, but it is unclear how widespread upward migration of poor quality groundwater might be.

Onshore oil and gas is not new to the UK – it has a 150 year history of oil and gas production and there are currently 250 producing wells at 120 sites (link). In the 1980s the BGS compiled temperature and chemistry data, where available, for over 1150 sites (Rollin, 1987) as part of an investigation into deep geothermal energy, although the median depth was only 1000 m, still providing a very limited window into the subsurface, particularly when considering the variability of geological settings  resulting from its complex structural history. For example, the basin size in the UK is on the order of ~40,000 km2 and has undergone multiple periods of deformation. Conversely, Western Canada Sedimentary Basin, which covers large parts of Saskatchewan and Alberta, has an area of the 1,400,000 km2.and is relatively undeformed in Saskatchewan. The decision making process must therefore be more site specific in England.

Population density is low northwestern North Dakota and southeastern Saskatchewan, but satellite imagery shows light from oil and gas development in the Bakken Formation (from NASA Earth Observatory).

In relation to groundwater, possible pathways from hydraulic fractures initially received most public attention in the UK. However, legislation (the Infrastructure Act, 2015) means that High Volume High Pressure hydraulic fracturing must take place deeper than 1000 m below the land surface – very few hydraulic fractures likely bridge this distance (Davies et al., 2014). The relatively high density of faults across all of the basins (resulting from this complex geological history) may be more of a concern if they could form permeable pathways since they tend to be longer, although the potential for flow along these faults is largely unknown. As in Canada, well casing and integrity is also a possible issue, but there are stringent controls on this – nevertheless, horizontal drilling may pose more of a problem in some instances (Bachu and Watson, 2009).

In England, all groundwater must be protected (Water Framework Directive, 2000) for human use/ecosystems. If little is known about the conditions in the subsurface, then the precautionary principle must be applied.  In practice, however, depths within 400 m of the land surface –depths that most groundwater is abstracted from – is used a default maximum depth. In North America, some jurisdictions define a base of groundwater protection based on depth but some may also do this on salinity (Lemay, 2008; DiGiulio, et al., 2018). There were discussions at the conference on how the depth of groundwater should be defined.

The conference provided a useful forum within which to share experience from North America, and the advanced Bakken Play in Canada, with delegates from the UK hydrogeology industry. It was clear, however, that while there is a lot of learning to be done from these examples, due to the differences both in legislation and geology, the UK hydrogeology community should not use these examples as a direct analogue for the UK industry.

* The conference addressed use of the deep surface in the UK, but groundwater legislation discussed here applies to England only

References

Bachu S, Watson TL (2009) Review of failures for wells used for CO2 and acid gas injection in Alberta, Canada. Energy Procedia 1: 3531-3537

Cherry J, Ben-Eli M, Bharadwaj L, Chalaturnyk R, Dusseault MB, Goldstein B, Lacoursière J-P, Matthews R, Mayer B, Molson J (2014) Environmental Impacts of Shale Gas Extraction in Canada. The Expert Panel on Harnessing Science and Technology to Understand the Environmental Impacts of Shale Gas Extraction Ottawa: Council of Canadian Academies.

Davies RJ, Mathias SA, Moss J, Hustoft S, Newport L (2012). Hydraulic fractures: How far can they go? Marine and Petroleum Geology. 37: 1-6

DiGiulio DC, Shonkoff SB, Jackson RB (2018) The need to protect fresh and brackish groundwater resources during unconventional oil and gas development. Current Opinion in Environmental Science & Health 3: 1-7

Infrasturcture Act (2015). C.7. Part 6. Other provision about onshore Petroleum, Section 50. http://www.legislation.gov.uk/ukpga/2015/7/section/50/enacted

Lemay TG (2008) Description of the Process for Defining the Base of Groundwater Protection, Edmonton, Alberta, pp. 27.

Rollin KE (1987) Catalogue of geothermal data for the land area of the United Kingdom. Third revision: April 1987. Investigation of the geothermal potential of the UK. British Geological Survey.

Water Framework Directive (2000) Water Framework Directive. Common Implementation

Whitton J, Brasier K, Charnley-Parry I, Cotton M (2017) Shale gas governance in the United Kingdom and the United States: Opportunities for public participation and the implications for social justice. Energy research & social science 26: 11-22

 

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.

 

How can we make hydrogeology free from plagiarism? Reflections five years after a documented case of plagiarism in the hydrologic sciences

How can we make hydrogeology free from plagiarism? Reflections five years after a documented case of plagiarism in the hydrologic sciences

Tom Gleeson and Matt Currell (just to be clear about our sources…header image from http://iditis.blogspot.ca/2006/03/plagiarism-lesson-learned.html)

Plagiarism is a clear contradiction of scientific values and practice. Although no universal definition of plagiarism exists, a useful working definition is the wrongful appropriation, stealing and publication of another author’s language, thoughts, ideas, or expressions and the representation of them as one’s own original work (wikipedia). Plagiarism in our digital world can be too easy – although journals have stepped up on electronically detecting and policing plagiarism (Nature, 2010), there is evidence that plagiarism remains depressingly common (Science and Engineering Ethics, 2015). A case of documented plagiarism in the hydrologic sciences offers a number of lessons about how every one of us has multiple roles in making hydrogeology free from plagiarism.

An extensive investigation and review by the Kansas Geological Survey and the University of Kansas concluded that seven papers written by Marios Sophocleous contained extensive plagiarism and self-plagiarism. Yet some of these plagiarized papers are still routinely citedfor example, Sophocleous (2002) has been cited >500 since the public censure in 2013. The detailed report of the detection and investigation of this plagiarism as well as the response by journals and suggestions on paths forward was written by Jim Butler: Draft Report on Plagiarism.

To get a better sense of the style and scale of the plagiarism it is useful to examine a marked up version of Sophocleous (2002) – a highly cited paper on groundwater surface water interactions: Sophocleous_GW-SW HJ Journal 2002 KGS Analysis for distribution.

The University of Kansas requested four journals to retract seven different papers published from 2000 to 2012. Although there are different forms and severity of plagiarism, we concur that this is a clear and unambiguous case of plagiarism, and is totally unacceptable.

Retraction Watch wrote useful summaries of the varied response of journals to this request for retraction: Groundwater and Natural Resources Research retracted articles (Retraction Watch post) while Journal of Hydrology and Hydrogeology Journal refused to retract (see Retraction Watch post; Hydrogeology Journal editorial and Journal of Hydrology editorial which usefully lists original sources but unfortunately is behind a paywall).  The articles were not retracted from Hydrogeology Journal because 1) “the reference from which the material was copied verbatim is given close by in the text by Sophocleous” implying “he was giving credit to the previous authors from which he copied, and not hiding the fact that the material was not his own.” and 2) the articles are highly cited which shows “clear value to the scientific community” (Hydrogeology Journal editorial). There are differing levels of plagiarism (including clear plagiarism, minor copying or redundancy) recognized by the Committee of Publishing Ethics which offered advice to Hydrogeology Journal and Springer on this case but the argument that the number of citations should have anything to do with whether a plagiarized article is retracted is spurious and irrelevant, and sets a dangerous ethical precedent. When popularity is considered to absolve the need for methodological rigor, and when it trumps the motivations and ethics behind our actions, we are not in a good place as a profession (or a society). Cliff Voss, Hydrogeology Journal Executive Editor, also clarified recently that he considered attaching an editorial to the non-retracted articles a better lesson in plagiarism since the plagiarized articles are then more visible for everyone to learn from, rather than just disappearing if they were retracted.

Part of the challenge of this case is that most references in the papers were not identifiable by plagiarism detection software because many were local reports or old references that are absent from the widely used database systems as explained by the Journal of Hydrology editorial. Instead, the assessment by the Kansas Geological Survey consisted of identifying possible copied passages and then electronically searching potential sources. The Kansas Geological Survey has importantly offered to make their analyses of the papers discussed in the Hydrogeology Journal editorial available upon request.

In a strange twist of fate, one of us (Tom) collaborated with Marios on two papers on groundwater sustainability as a postdoctoral fellow – totally oblivious to the pending investigation into his papers. For both groundwater sustainability papers (Gleeson et al 2010; Gleeson et al 2012), Tom lead the writing with a number of other coauthors editing and contributing text – Marios largest contribution was to the ‘High Plains Aquifer’ section of Gleeson et al. 2012. Given the above limitations of plagiarism software, Tom conducted his own investigation of this section, going line by line through and electronically searching potential sources for each line. He did not find any lines that had clearly come from other sources and found that the referencing was proper and consistent at the end of sentences throughout this section.

The public censure, the above report from Jim Butler, and the response from journals reinforces a number of lessons about how every one of us has multiple roles to play in rooting out plagiarism. So this leads to…

How can we make hydrogeology free from plagiarism?

The report from Jim Butler attached above has a number of useful recommendations for reviewers, readers, editors, professional societies and publishers, and universities/research institution that could help make hydrogeology free from plagiarism. We echo all of these important recommendations and add a few additional recommendations from my own reflections and experience:

For anyone writing academic articles:

  • Be vigilant about plagiarism in papers that you are citing and stop citing papers that have documented plagiarism. In the case of the papers part of a public censure for plagiarism from University of Kansas, instead request marked up version from the Kansas Geological Survey and cite the original sources of text; this is more ethical and will lead you to some interesting old literature that deserves citing.
  • Be vigilant about plagiarism with your own writing and the writing of your coauthors – now every time we start to copy any text we stop, and consider whether this could potentially lead to plagiarism.

For educators – use this case as an example to talk about plagiarism in your classes. We have done this tactfully a number of times in senior undergraduate and graduate classes.

We all need to work hard to make hydrogeology free from plagiarism and we all have multiple roles in this as writers, reviewers, editors, supervisors, coauthors etc. – we hope this article will help in some small way encourage us all to take the high road. We conclude with a few open questions that touch on deeper issues about the ethical challenges in the modern academic system (these can evolve into future posts if there is interest):

  • What are the incentives and pressures which drive people to plagiarize like this case? Is there a problem with the system of rewarding researchers who publish large numbers of articles (e.g., through improved chances of securing tenure and/or academic promotion)?
  • How can we properly acknowledge the source(s) of our ideas when there is so much literature out there which overlaps and recycles old ideas?
  • How can we stop the tide of what Frank Schwartz termed ‘Zombie Science‘ (research that makes little original contribution), while still giving early career researchers opportunities to learn and apply established techniques and publish their work even if it is not particularly ground-breaking