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.


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)


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.


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:



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









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

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.


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:


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.


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.



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.

Happy birthday plate tectonics!

Happy birthday plate tectonics!

Post by Elco Luijendijk, a junior lecturer, and David Hindle, lecturer and head of geodynamic modelling, both at the Department of Structural Geology and Geodynamics at the University of Göttingen, in Germany.


As we’ve firmly moved into 2018, we can say happy 50th birthday to one of the most revolutionary scientific theories of the last century: plate tectonics. Here we discuss the birth of plate tectonics and what it means for hydrogeology.

Plate tectonic theory explains the how the Earth’s surface is formed and how it consists of rigid plates on top of a layer that is called the asthenosphere and that behaves like a slow-moving liquid. The plates move around, collide and subduct beneath each other. Plate tectonics successfully explains many features of the surface of the Earth, such as mountain belts at the collision zones of plates, ocean basins at places where plates move apart and the concentration of earthquakes near plate boundaries. For instance it is quite easy to recognize the boundaries of tectonic plates if you look at the earthquake distribution in Figure 2.

Plate tectonics birthday cake, showing one tasty tectonic plate (left) subducting below another (right). Source: http://sara-geologicventures.blogspot.de/2012/05/cake-subduction-zone.html

Actually, depending on your definition either 2017 or 2018 is the 50th birthday of plate tectonics. The story why this is the case is a bit complex. Jason Morgan first presented the theory at meeting of the American Geophysical Union (AGU) in 1967. However, the first paper on the mathematical principle of the movement of tectonic plates was published in the same year by McKenzie and Parker (1967). Jason Morgan’s paper (Morgan 1968) is the first one to clearly demonstrate the global geometry of all the major tectonic plates, but had got delayed by peer-review for over a year. The development of plate tectonics involved many scientist and several earlier theories, such as seafloor spreading (which showed that ocean basins were split in two halves that were moving apart). There are surprisingly few books available on the history of plate tectonics, but one that is definitely an enjoyable read is “Plate Tectonics: An Insider’s History Of The Modern Theory Of The Earth” (Oreskes 2003). It is a fascinating collection of stories by most of the scientist that were involved in the development of the theory.

Figure 2 Plate boundaries on earth, with earthquakes > M6.5, since the year 2000, and with selected relative motion arrows for plate pairs – the motions shown are always those between adjacent plates. Double arrows imply spreading – moving apart of plates, mostly on oceanic ridges, while single arrows imply either strike slip motion (California and the San Andreas fault for instance) or convergence (either subduction of an oceanic plate under a continental one – under the Andes mountains in South America as an example, or collision of two continental plates as between India and Eurasia in the Himalayas for instance). Earthquakes are clearly concentrated on plate boundaries. This map was made using GMT (http://gmt.soest.hawaii.edu/).

Ok, that is all very interesting, but you could ask the question: what does plate tectonics have to do with Water Underground?

In some regards not much. We can often ignore plate tectonics when looking at groundwater flow. Hydrogeologists tend to study groundwater supply and pollution on human time and space scales. Because plates move very slowly (up to tens of mm per year), on short timescales the subsurface can be regarded as static layer of rocks that does not move or deform. However, most of the groundwater on our planet is old, and has infiltrated to the subsurface ten thousand years ago or earlier (Jasechko et al. 2017). The oldest groundwater that we know is 1.5 billion years old and was found at 2 km depth in a mine in near Timmins, Canada (Holland et al. 2013). Over its long history it was part of ancient and long disintegrated continents and the plate that holds this water moved from an area south of the equator to its present position.

Plate tectonics affect groundwater. Especially in deeper (several kilometers) parts of the crust, the groundwater pressure, salinity and composition that we encounter today are often the result of a long geological history. Over time, sediments were added and removed by erosion, layers were compacted, folded and/or faulted, which affected groundwater flow and its interaction with the rocks that contain it.

The reverse is also true: groundwater affects plate tectonics. This is perhaps most important near mid-ocean ridges, where two plates move apart, and new crust is being added to these plates all the time. There is abundant evidence for strong circulation of seawater through the subsurface, which cools the hot new crust, reacts with the rocks around it and changes the chemistry of the crust and the ocean. The most visible evidence are so-called black smokers (Figure 3), where hot (350 ˚C) water discharges into the ocean through fissures in the crust and carries along black plumes full of dissolved minerals. At the opposite end of the plates, the presence of water underground changes how easy or hard it is for one plate to subduct beneath another in a plate collision zone, as was discussed at a recent AGU conference (link to session), 50 years after the AGU conference where Jason Morgan presented his theory. On a smaller scale, faults that enable the stacking of rocks in plate collision zones (mountain belts) or the breaking apart of rocks in rift zones (where plates split up), are dependent on the presence of groundwater. Even before the advent of plate tectonics Hubbert and Rubey (1959), showed that water in fault zones can act as a kind of lubricant that enables two adjacent blocks of rocks to move past each other. Because this movement gives rise to earthquakes, groundwater may also play an important role in the earthquake cycle. This role is still heavily debated and is researched by drilling deep wells in faults at plate boundaries, such as at the San Andreas fault in California (Zoback et al. 2010) or the Nankai through (Hammerschmidt et al. 2013).

Without sufficient groundwater plate tectonics may not exist on our planet. The movement of tectonic plates depends on how easily the rocks below these plates can deform. At these depths, high pressures and temperatures promote the slow deformation of the crystals that make up the rocks at this depth. The mechanisms that cause the deformation of crystals are termed “creep”. Whether or not the rock contains water (in the form of -OH groups) affects creep: generally, “wet” minerals are up to a factor of 10 “softer” than “dry” ones. The actual physics and chemistry of how -OH affects and weakens different minerals is not entirely clear. Creep is also essential for the convection of the earth’s mantle, which controls the escape of heat from our planet’s interior and provides the energy to drive plate tectonics. Without convection, there would be no plate tectonics, so the presence of water throughout the earth’s crust, and its continued reintroduction to the earth’s mantle by the subduction of tectonic plates seems to be a key component driving the system, or at least, helping it to keep moving along.

There are many more links between groundwater and geologic processes, too many to cover in a short blog item like this. However, the current state of our understanding is summarized in a highly recommended book “Groundwater in geologic processes”. Many aspects of groundwater flow and its links with geological processes in newly formed, colliding or subducting plates are still uncertain and studied by hydrogeologists, which means that 50 years after the publication of the theory of plate tectonics, many discoveries still lie ahead.

Figure 3 A black smoker at the mid Atlantic ridge emitting hot groundwater into the ocean from newly formed oceanic crust. Copyright: MARUM – Center for Marine Environmental Sciences, University of Bremen.


1: McKenzie and Parker (1967) https://www.nature.com/articles/2161276a0

2: Morgan (1968): http://onlinelibrary.wiley.com/doi/10.1029/JB073i006p01959/full

3: Oreskes (2003): https://www.routledge.com/Plate-Tectonics-An-Insiders-History-Of-The-Modern-Theory-Of-The-Earth/Oreskes/p/book/9780813341323

4: Jassechko et al. (2017): https://www.nature.com/articles/ngeo2943

5: AGU fall meeting session (2017): http://agu.confex.com/agu/fm17/meetingapp.cgi/Session/31184

6: Hubbert and Rubery (1959): https://pubs.geoscienceworld.org/gsabulletin/article-lookup/70/2/115

7: Zoback et al. (2010): http://onlinelibrary.wiley.com/doi/10.1029/2010EO220001/full

8: Hammerschmidt et al. (2013): https://www.sciencedirect.com/science/article/pii/S004019511300098X

9: Ingebritsen et al. (2006) Groundwater in geologic processes. http://www.cambridge.org/de/academic/subjects/earth-and-environmental-science/hydrology-hydrogeology-and-water-resources/groundwater-geologic-processes-2nd-edition?format=PB&isbn=9780521603218#RcR6adP330ESbBPk.97


David Hindle (L) is a lecturer and the head of geodynamic modelling in the Department of Structural Geology and Geodynamics at the University of Göttingen, and Elco Luijendijk (R) is a junior lecturer also in the Department of Structural Geology and Geodynamics at the University of Göttingen.

A cool new collectible: Water

A cool new collectible: Water

Post by Matt Herod, Waste and Decommissioning Project Officer for the Canadian Nuclear Safety Commission, and Adjunct Professor in Earth and Environmental Science at the University of Ottawa, in Ottawa, Canada.


I have always been a mineral and fossil collector. It was a hobby that stuck and blossomed into a career. I still collect minerals and fossils, although I’ve now added rocks from my field sites to the collection. One thing I should note is that for inanimate, immobile objects it is shocking how quickly rocks can colonize parts of a house, garage, basement, etc.

However, since my early years in geology a very large part of my day is concerned with water; my PhD was almost exclusively about water. Water is my focus and it is truly fascinating. So that got me thinking. Why don’t I collect water?

You may think water is all the same. Turn on the tap, it comes out, drink, wash, whatever. It’s just water. Well, you could not be more wrong. Water is different and changeable. Plus it fits in a small bottle. In short, the perfect collectible.

But maybe you’re not convinced to start collecting water just yet.

Water has types, an identity, just like people. You may be familiar with the notion of people’s personalities being Type A’s, B’s and C’s. Although the types of water are a little more nuanced. That said, so are the types of people.

Water is sorted into types based on its chemistry. The chemistry of water comes from the dissolved salts within it and the relative concentrations of those salts. The isotopic composition of water can also be used to identify its type. Some water types are classed based on their heritage. For example, water found in pore spaces deep underground is often called brine, the precursor to that brine is, or often was ancient ocean water.

Let me give you some examples of water with interesting identities. One thing I should mention is that many of the ways waters are typified only consider their dissolved salt concentration, however, when you factor pH, Eh, and isotopic variation of the many, many different isotopes the number of water types balloons exponentially. For example, a water with a pH of 6 and a total dissolved solids (TDS) concentration of 500 ppm can have isotopic ratios, age and origin totally different from another water with the same pH and TDS. Like I said, it gets complicated fast.

To start with an easy one:

Seawater: Not only is it familiar, it is pretty important given that 97% of Earth’s water is this type and a significant percentage of Earth’s biomass lives in it. Seawater is about 3.5% saline and one of the most interesting features of the water is that it is pretty much everywhere and chemically very consistent. There are differences in the composition of seawater in the certain places around the world, for example, in restricted basins salinity can be higher or where fresh water enters the ocean in a river delta or estuary salinity is lower. Isotopically seawater is also interesting. Not because it has an unusual isotopic composition, but because seawater has been set as the standard to which all other water is compared. It is the zero point that stable isotopes in all other water is measured against.

Glacial Water: Of the 3% of Earth’s water left after the oceans, 69% is frozen in glaciers. To condense the characteristics of glacial water into one word I’d say clean. It just doesn’t have much in it. The reason for this is that glacial water started its days as precipitation, which is water that was evaporated from a water body and condensed. The evaporation process removes almost all of the dissolved solutes. Therefore, there just isn’t much stuff in glacial water besides the H and the O. That doesn’t mean glacial water is boring though. There is still a lot that if can tell us. For example, the variations in O isotopes can be used to reconstruct past temperatures and gases trapped in the ice can tell us about the composition of past atmospheres as well. The information we get from glacial water is different, but extremely valuable!

Brine: Do not drink a brine. You WILL regret it. I do not speak from experience, but frankly if almost 30% of the fluid is salt, it simply isn’t drinkable. Brines come in a lot of flavours, and technically if it has >5% salt it’s considered brine. However, I have encountered some brines that are over 30% saline. Of course, they were not drinkable as they were porewater in a sedimentary basin. However, there are some extremely salty bodies of water out there as well. Brines are interesting because they have so many stories to tell. There is history there, recorded by the solutes, gases and isotopic composition of the brine that explains how it became more than a simple water and transcended the label of water entirely to become much, much more…a fluid. Typically brines in nature have a history that involves salt dissolution leading to high concentrations of Na and Cl. However, other types may simply be evaporated seawater causing all of the dissolved ions to become more concentrated. For example, brines often have high concentrations of Ca, Br, I, Sr, etc, etc. Isotopes in brines also reveal a lot about their past and can distinguish if a brine is a glacial water that has dissolved salt, or is evaporated seawater or has a hydrothermal component. There is just always more that you can find out about brines.

High and low pH waters: pH plays a huge role in dictating the chemistry of water and the dissolved salts therein. Around the world there are naturally occurring waters that have incredibly high and low pH’s. The low pH waters, typically around 1-3 on the pH scale, occur in areas where natural acid rock drainage is happening. Acid rock drainage, aka. ARD, happens when sulphide minerals, often pyrite, oxidize releasing sulphuric acid leading to seeps with exceedingly low pH’s. On the other hand, high pH waters occur more rarely. Alkali springs occur when water comes in contact with hydroxide minerals, such as calcium hydroxide. Hydroxides form in dry, arid environments or where organics and limestone have been heated and burned such as areas with volcanic activity. One famous alkali spring is the Maqarin site in Jordan where water with pH’s from 11-13 occur!

Hydrothermal waters: HOT, HOT, HOT! These waters are absolutely loaded with interesting chemistry. Spewing out of hydrothermal vents on the seafloor at temperatures of up to hundreds of degrees Celsius with tons and tons of dissolved metals like copper, lead, gold, zinc, silver, etc. Furthermore, many of the world’s metal deposits are related to the movement of hydrothermal fluids within the crust. Hydrothermal fluids get their heat from the mantle or magma chambers within the crust. As they are heated they dissolve the rocks in contact with then leading to highly enriched solute concentrations and then when they discharge and cool, the solutes precipitate leading to black smokers, or mineral precipitates in fractures in the crust.

Young and old waters: My last Water Underground post discussed this in more detail. Suffice it to say when you start analyzing carbon-14, tritium, chlorine-36, iodine-129, krypton-85 and 81, etc. you can find waters ranging in age from just a few years to tens of millions to billions of years old. Each of these, is worthy of a spot on my shelf that is for sure. Excitingly, each of these waters has a story to tell about its origin and experiences over the years. Analyzing these isotopes and putting them in context with the geologic history of where the water is found can explain a lot about the regional hydrologic cycle and how water recharges, and discharges and how vulnerable the aquifer it is housed in is to contamination or over-pumping.

This is just the tip of the iceberg (see above). There are many ways water is sorted into types, often called “facies”, which are then plotted graphically. Here is a nice paper that compares some of the different ways of plotting water [1]. Read all the way to the end an you’ll be rewarded with a somewhat strange smiling face.

Anyway, hopefully I’ve convinced you to grab a bottle and collect a sample or two when you come across an interesting water!

Finally, my only piece of advice if you’re going to start a water collection…make sure the top is screwed on tight.


[1] Güler, Cüneyt, et al. “Evaluation of graphical and multivariate statistical methods for classification of water chemistry data.” Hydrogeology journal 10.4 (2002): 455-474.


Matt Herod is a Waste and Decommissioning Project Officer for the Canadian Nuclear Safety Commission, and an Adjunct Professor in Earth and Environmental Science at the University of Ottawa, in Ottawa, Canada. To keep up to date with Matt, follow him on Twitter or on his own EGU blog GeoSphere!

From groundwater flow to groundwater glow: why does groundwater fluoresce in ultraviolet light?

From groundwater flow to groundwater glow: why does groundwater fluoresce in ultraviolet light?

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


We often come across items that glow after being exposed to ultraviolet light. Fluorescent stickers can be bought for the ceilings of bedrooms; fluorescent hands on analogue clocks and watches; fluorescent markings on a car dashboard.

In all these examples, there are organic molecules that absorb energy in the form of ultra-violet light and can then re-emit that energy, in this case as visible light. We are talking fluorescence. Or when the emission of light is delayed, phosphorescence. It requires loosely-held electrons to be present in a molecule. The energy provided by ultraviolet light can excite these electrons to a higher energy level, and when the electrons return to a lower energy level, light is emitted. This emitted light has to be at a longer wavelength than the excitation energy, and if it occurs at wavelengths our eyes can detect, then we can see it. Hence the blue-green colours of watch hands and plastic ceiling stars.

What about groundwater? It’s the same process: if we shine ultraviolet light at groundwater samples, then they fluoresce due to the presence of organic molecules that are often present. Unfortunately, we can’t see any of this fluorescence with our eyes, as it is emitted in the middle- and long-range ultraviolet, so we must use detectors that can ‘see’ at these wavelengths. But that is relatively easy – charge coupled devices (CCDs), the same as you would find in a digital camera, detect in the ultraviolet. And we can add in improved light emitting diode (LED) technology, which can now produce higher-energy, shorter-wavelength ultraviolet light to excite fluorescent molecules. It’s the same technological improvement that means that you can now buy blue LEDs to decorate your house – have you noticed how they have become increasingly available – and potentially keeps you awake at night.

Why does groundwater glow in ultraviolet light? Firstly, it could be from natural organic matter. Organic matter is transported by rivers, which may be recharged to groundwater where rivers are ‘losing’. Or it might be leached from the overlying soil during rainfall recharge of groundwater. Or it might be desorbed from sedimentary material in the aquifer. Natural organic matter fluorescence tends to occur at longer ultraviolet wavelengths (360-400 nm) and provides a convenient way of detecting dissolved organic matter.

Secondly, groundwater samples might fluoresce due to the presence of microbial matter. In rivers and wastewater systems, the amount of fluorescence at shorter ultraviolet wavelengths (300-350 nm) has been observed to correlate with the amount of oxygen being consumed (the biochemical oxygen demand, or BOD). It is not possible to distinguish between individual or groups of microbial species, and researchers are still investigating exactly what is fluorescing. However, recent research has shown that there is significant potential in using hand-held fluorescent probes to determine microbial water quality in groundwater. Where there might be faecal contamination of groundwater used for drinking water supply, there is great advantage to this method as an immediate reading is possible in comparison with other methods which typically take 18-30 hours.

Thirdly, groundwater which is contaminated by organic matter may be detected if enough of the contaminant is fluorescent. For example, fluorescent whitening agents, also known as optical brighteners, may be added to detergents, shampoo and paper products to make items appear whiter.  The molecules are designed to emit light at the blue-violet end of the visible light spectrum, and it counters any yellowing of aging fabric, paper or hair. Hence your clothes appear whiter, your hair blonder. Fluorescent whitening agents are removed during wastewater treatment and degrade in sunlight. But in the case of unlined landfill sites, fluorescent whitening agents can persist in contaminant plumes in the groundwater, making them a useful tracer.

So why does groundwater glow in ultraviolet light? It is all to do with any fluorescent organic matter that might be present in groundwater. And thanks to improvements in technology, we can now make measurements of this fluorescence using portable and handheld probes, in-situ, and rapidly. Increasingly adopted by surface water quality researchers and water engineers, is it time for the groundwater community to move on from groundwater flow to groundwater glow?

A Tanzanian groundwater safari through the last 2 million years

A Tanzanian groundwater safari through the last 2 million years

Post by Mark Cuthbert, Research Fellow and Lecturer at Cardiff University, in the United Kingdom, and by Gail Ashley, Distinguished Professor at Rutgers University, in the United States.


During the dry season, Lake Masek in Northern Tanzania (see map) is a lovely place to be if you’re a hippo or a flamingo, but for humans it’s an inhospitable environment. We were on ‘safari’ (a scientific one of course, but the wildlife was a massive bonus! Photo 1-left) to try and better understand the distribution of freshwater in this dryland landscape.

Map: Locations on our groundwater safari in Northern Tanzania.

Watching our backs in case of predators, we ventured out of the safety of our Land Rover for Gail to sample the lake water, as salt blew in drifts around us off the desiccated edges of the lake bed (Photo 1-right). It was very salty and not potable for humans. All the streambeds that run into the lake were dry and yet our Masai guide told us that nearby we could find freshwater all year round.

Photo 1: (L) The amazing wildlife in the Ngorongoro Crater & (R) Saline-alkaline Lake Masek.

Intrigued, we set off around the edge of the lake and as we came over the crest of a small ridge were met with the most remarkable site – 1000s of cattle and goats queuing up for water from pools on the edge of the dry river valley just downstream of the lake. We waited for the queues of animals to die down and asked permission from the local guardians of the water source to investigate (Photo 2). The pools turned out to be fed from groundwater flowing out of rocks at the side of the valley. In contrast to the salty water from the adjacent lake, these springs were fresh and potable. We think the water is very old having originally fell as rain on the flanks of the ancient Ngorongoro Highlands (see map) before flowing slowly under gravity through layers of volcanic rocks 10’s of km to the springs. Because there’s so much groundwater stored in these rocks, and because they are not very permeable, the water seeps out quite slowly. So the springs keep running all through even the longest droughts and are vital water supplies for local people.

Photo 2: Asking permission to sample at Eremet springs

We travelled east along the same dry river valley in which we’d encountered the springs. Here the river, which only flows during the wet season, has cut itself into a steep ravine called Olduvai Gorge. We walked down the side of the gorge travelling back in time ~2 million years, the rocks and sediments around us telling a well-documented story of how the environment has changed over that time. Many exciting fossil discoveries have also been made in the gorge including some of our oldest human ancestors (Photo 3-left). For us one of the most interesting discoveries was geological evidence of ancient springs (Photo 3-right) found in the same layers as fossil human ancestors and stone tools which Gail has documented going all the way back to nearly 2 million years ago (read more here). There are clues from the surrounding sediments that there was a lake nearby but it was salty and alkaline, and we think the springs would have kept flowing for 100s or even 1000’s of years during persistently drier periods experienced in the past (read more here).

The springs that were flowing in the Olduvai area 2 million years ago, just like the springs on the margins of present day Lake Masek, would have been the only freshwater for miles around and vital for sustaining life during dry periods. Since there are hundreds of freshwater springs dotted around present day drylands in the East African rift system, we can hypothesise that during dry periods in the past, similar locations would have acted as ‘hydro-refugia’ – places where animals could find the necessary freshwater for survival in an otherwise dry landscape. In dry periods there would be lots of competition for these resources and populations would have become isolated from each other for quite long periods. During wetter periods springs would have enabled our ancestors and other species to move long distances across the East African landscape and beyond, acting like stepping stones connecting river corridors and lakes and enabling populations of different species to encounter one another (read more here). Groundwater was likely therefore an important control on the movement and evolution of humans in this environment.

Photo 3: (L) Paranthropus boisei (‘Zinj’) hominin skull found at Olduvia gorge (Photo Credit: Tim White PhD, Human Evolution Research Center, University of California, Berkeley) & (R) Mark Cuthbert next to a tufa (calcium carbonate) deposit thought to be evidence of groundwater discharging near the site that the Zinj fossil was found.

Groundwater is often ‘out of sight and out of mind’. Our safari gave us a glimpse into its importance in sustaining life in a dryland environment not just in the present day, but also for our ancestors going back at least 2 million years through some climatically turbulent periods. The challenge going forward is how that groundwater resource can be protected to make sure it’s there when it’s needed in the face of an uncertain climatic future.

Acknowledgements: it has been a massive privilege to be able to explore this landscape and ponder how freshwater has shaped life here over millions of years. Particular thanks to our guides Joseph Masoy and Simon Matero, logistical support from Charles Musiba (LOGIFS – Laetoli-Olduvai Gorge International Field Camp) and TOPPP (The Olduvai Paleoanthropological and Paleoecological Project), our hosts at the Ngorongoro Conservation Area Authority, and all our collaborators on the papers cited.


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 & quantify groundwater sustainability; to improve interpretations of terrestrial paleoclimate proxy archives; to understand Quaternary paleoenvironments & how they influenced our evolution as a species. Read more on Mark by clicking on the links below.

TwitterResearch website




Gail M. Ashley is a Distinguished Professor and Undergraduate Program Director of Quaternary Studies Program at Rutgers University, in the United States. Gail studies modern physical processes and deposits of glacial, fluvial, lacustrine, arid landscapes, and use this information to interpret paleoenvironments. Read more about Gail by going to her research website.

Want to contribute to IAHS’ discussion about 23 unsolved problems in hydrology?

Want to contribute to IAHS’ discussion about 23 unsolved problems in hydrology?

Inspired by the famous list of unsolved math problems (hence the header image), the International Association of Hydrological Sciences has an interesting challenge for us all: define 23 unsolved problems in hydrology:

The International Commission on Groundwater is going to submit a few problems via the LinkedIn forum. A few of us at Water Underground are going to put our thinking caps on and submit a problem or two. If you would like to be part of the discussion very early in 2018, get in touch with Tom Gleeson.