WaterUnderground

active learning

Of Karst! – short episodes about karst

Of Karst! – short episodes about karst

Episode 2: Dissolving rock? (or, how karst evolves).

Post by Andreas Hartmann, Lecturer in Hydrology at the University of Freiburg (Universität Freiburg), in Germany. You can follow Andreas on twitter at @sub_heterogenty.

Didn’t get to read Episode 1? Click this link here to do so!

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In the previous episode, I introduced karst by showing how it looks in different regions in the world. This episode will now deal with the processes that create such amazing surface and subsurface landforms. The widely used term “karstification” refers to the chemical weathering of easily soluble rock composed of carbonate rock or gypsum. Most typical is karstification of limestone (consisting of the mineral calcite, CaCO3) or dolostone (consisting of the mineral dolomite, CaMg(CO3)2). If exposed to CO2 rich water these rocks are dissolved to form aqueous calcium (Ca2+) or magnesium (Mg2+) and bicarbonate (HCO3 ) ions. For calcite, karstification is described by the following chemical equilibrium:

The dissolution of carbonate rock depends on various factors. Imagine a solid block of salt, which you pour water on. If completely solid, the water will flow down the salt surface slowly dissolving the block. If fractured, water will eventually enlarge the fractures in the salt block and dissolution will occur much faster. Now imagine smashing the salt block before pouring water on it. In such circumstances the salt will dissolve even faster as the surface area exposed to the water is much larger.

Karst and its evolution (educational video provided by Jennifer Calva on Youtube).

The same is true for karstification. If the carbonate rock is heavily fractured, it will dissolve faster than unfractured carbonate rock. Another factor is the availability of CO2, that depends on the relative amount of CO2 in the air, air temperature and soil microbiotic processes. Other factors are the purity of the carbonate rock, the availability of water, and the supply of CO2 from the surface. As soon as karstification takes place, more water will be able to pass the dissolution enlarged fractures providing more and more CO2, and creating a positive feedback between rock dissolution and water flow:

Positive feedback between carbonate rock dissolution and water flow (Hartmann et al., 2014, modified).

The hydrochemical processes described in this episode of the Of Karst! Series not only create beautiful karst landscapes but they also have a strong and particular impact on water flow paths in the subsurface, which will the topic of episode 4 that can be expected in early 2018. Before, I will present a special feature about karst in the movies as topic of episode 3 in autumn 2017.

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. Reviews of Geophysics, 52, 218–242, doi: 10.1002/2013rg000443.

Ford, D.C. & Williams, P.W. 2013. Karst Hydrogeology and Geomorphology. John Wiley & Sons, 576 pages.

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Andreas Hartmann is a lecturer in Hydrology 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.

 

Research mini-conference in fourth year groundwater class

Research mini-conference in fourth year groundwater class

Fourth year and graduate students led a fun mini-conference during class in Groundwater Hydrology (CIVE 445, Civil Engineering at University of Victoria) yesterday. Local consulting and government hydrogeologists joined, making the students both nervous and excited to be presenting to professionals with up to forty years of groundwater experience. The presentations were the culmination of a term-long independent group research project – they also write a research paper (which is peer-reviewed by their classmates). And the mini-conference culminated in beers at the grad club, unfortunately drinking beer brewed with surface water.

It seemed like a win-win-win for everyone. The students loved meeting and presenting to, and being grilled by, the people who had mapped the aquifer they were modeling or asked if their model is based on any real data. The practitioners loved seeing the new ideas and enthusiasm of the students. And I loved seeing the interaction and learning.

For any prof reading this, here is a description of the Group Research Project and the conference poster:

 

 

 

 

 

Can we use an infrared camera to tell us how much groundwater is coming out of the side of a cliff?

Can we use an infrared camera to tell us how much groundwater is coming out of the side of a cliff?

By Erin Mundy – a plain language summary of part of her Masters thesis

Groundwater is an important resource, with approximately 2 billion people around the world using groundwater everyday. Although most groundwater is beneath our feet, sometimes groundwater leaks out of stream-banks, hill sides and cliff faces – this is called groundwater seepage. Current scientific methods are not able to measure the amount of groundwater that leaks out of these landscapes. Scientists have used infrared cameras (cameras that show the heat of an objects) to identify groundwater seepage on hill-slopes and stream banks (Figure 1).

seep1

Figure 1. Digital image (a) and temperature image (b) of a seep in the summer and a digital image (c) and temperature image (d) of the same seep in the winter

This is because groundwater has an distinct heat signal, having a relatively constant temperature throughout the year (~10 degrees Celsius). Building on these studies, we hoped to find out the possibilities and limitations of using infrared cameras to measure the amount of groundwater that leaks out of the side of a cliff. We wanted to test if groundwater was flowing out of a cliff face slowly in the summer would warm up as it traveled down the rock, so the heat signature of the groundwater would go from cool water (that comes out of the rock, ~10 °C) to warmer water (warmed due to the sun and air temperature). On the other hand, we wondered if groundwater was flowing fast out of the cliff-face, it would not have time to warm, because the cool groundwater would be consistently running over it. In the winter, we believed the opposite would happen, that the groundwater would be warmer, relative to the surroundings, and show a cooling trend as the water traveled down the rock.

 

We found an unused mining pit in Saint Dominique, Quebec, that had lots of groundwater seeps coming out of the exposed rock, and used this as our test location. The mining pit had 3 different levels, as shown in Figure 2.

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Figure 2: an aerial shot of the quarry with the seeps labeled.

We took infrared and optical photographs of the seeps during seven visits that spanned from January 2013 – October 2014. Three visits took place during the winter (January – February 2013), coinciding with periods of below freezing so that the effect of extreme cold on seeps could be analyzed. Four visits took place during the summer/fall (June – October 2014), coinciding with sunny and hot conditions, and cloudy and warm conditions in order to determine the effect warmer temperatures have on seepage. In addition to these visits, we also completed a 24-hour experiment, where we took infrared pictures of two seeps every half hour for 24-hours, to determine the effect of sunlight and changing air temperature on the seep temperature signature. We also created an “artificial seep” experiment, where we released water from two large tubs over the cliff at the pit for 8 hours; one tub had water released at a slow rate, while the other at a faster rate, to see if we could replicate the heat signals from the real seeps. We took pictures with the infrared camera every half hour for eight hours for that experiment. We analyzed the infrared photos from each visit using a computer software that allowed us to determine the temperature along the seep.

In the winter, groundwater flows out the rock at warmer temperatures than it’s surroundings, making it easily distinguishable. We found that there was a clear relationship between seeps with active groundwater flow and areas of ice growth on the following visit. So, in the winter, if you use an infrared camera to locate where groundwater is flowing on the side of a cliff, you can assume there is a good chance that ice will eventually form at these spots. However, the groundwater did not cool along the rock face, as we had expected it would. This suggests frozen seeps are complex and it is unlikely that temperature pictures can determine the rate of flow of groundwater seeps in the winter.

In the summer, we found that lower flowing seeps did warm up as the water traveled down the rock face, as compared to faster flowing seeps, which did not show as much warming. However, in the 24-hour experiment (where we took infrared pictures every half hour for 24 hours of two seeps), we found that the temperature signature of the seeps changed throughout the day. During the day, there was much more warming of the groundwater as it traveled down the cliff, whereas at night it did not warm as much. This is most likely due to the presence of sunlight and warmer air temperature during the day, which warms the water more as it is traveling down the rock.

In the “artificial seep” experiment, we found that the “seeps” showed more warming than the real seeps. This is probably because we only ran the experiment for 8 hours, so it did not have time to mimic the conditions of real seeps. Also, we noticed that instead of flowing down the rock face, some of the water was actually seeping into the rock, along the breaks in the rock. This may be another reason why the seeps showed more warming, as not enough water was flowing down the rock (instead it was flowing into it).

After completing these experiments, we have concluded several possibilities and limitations for infrared pictures of groundwater seeps.

Possibilities:

  • Locate groundwater seeps in all seasons
  • Locate groundwater seeps in winter and from this, areas of ice growth can be predicted
  • Distinguish between lower flowing seeps and higher flowing seeps in summer (lower flowing seeps have more warming as the water travels down the rock face, higher flowing seeps do not have as much warming)

 Limitations:

  • Need to have a large difference in temperature between the air and groundwater to notice seeps. During the third winter visit, only one seep was identified to be flowing by the infrared camera. However, visual observations showed that eight seeps had groundwater flowing. This is because the temperature of the groundwater was too similar to the temperature of the air, making it not possible to detect the groundwater flow.
  • Groundwater seeps in the winter are complex and do not show a cooling trend, therefore it is unlikely that temperature pictures can determine the rate of flow of groundwater seeps in the winter
  • Breaks in the rock affect the flow of seeps, redirecting the flow, making it hard for temperature pictures to accurately determine flow
  • Sunlight and air temperature affect the “warming” and “cooling” of the groundwater flow, with more warming present during the day and less at night. Focus needs to be on determining the optimal time to use infrared pictures to show the “warming” (or “cooling”) trend.
  • The infrared camera itself has limitations. To use some functions of the camera, you have to correct your data for certain factors (like angle of the camera, humidity, etc.). If you don’t, you won’t be showing accurate data. This limits the amount of things you can do with the infrared camera and must be taken into account in order to ensure the pictures you captured are correct.

 

Despite the large number of limitations, infrared pictures is effective at locating groundwater seeps in all seasons, and able to distinguish between lower flowing seeps and higher flowing seeps (in the summer), which makes this technique a valuable, non-invasive way to study groundwater seepage. Future work should look at determining the optimal time to capture infrared pictures of seeps to determine a relationship between groundwater flow and temperature signatures.

 


 

How to peer review: skill-building in a grad classes

How to peer review: skill-building in a grad classes

I teach how to peer-review in graduate class because I think it is a core skill for any professional.  I first demystify peer-reviewing and academic journals, and answer questions that all students have about these topics that they have heard about but rarely learn about using this:

peer review

Nicholos and Gordon EOS, 2011

I describe my personal experience as a manuscript submitter, reviewer and associate editor. And then I outline the structure and types of questions to ask during a peer review (both listed below), and challenge them with three, increasingly difficult steps to learn how to peer review:

  • first, peer review already published papers (which is surprisingly hard since it is already well edited but this is useful as practice and since it is impersonal).
  • Second, peer review an open access manuscript that is currently in review (i.e. HESSD  or other open access journal). These can be actually submitted to the journal or not.
  • Third, they peer-review eachother`s term papers before final submission of paper to me as part of the grade.

At each step myself or a TA gives them feedback and evaluates their peer reviews.

Good structure for a peer-review

  • Short summary (1-2 sentences) and general assessment of novelty/contribution. Give the author(s) a few compliments here….everyone likes to eat the good-bad-good sandwich rather than just the bad sandwich.
  • Discuss major concerns or suggestions for authors. Aim for positive criticism here.
  • Recommend course of action: reject, accept with major revisions or accept with minor revisions.
  • Document minor concerns with explicit page and line numbers.

Good questions to ponder:
Contributions and Audience:
What are the important contributions of this paper?
Does the paper make a significant, new contribution to this research area?
Who is the intended audience?

Technical soundness:
Are the methods fully described?
Is the mathematical/theoretical development (if any) complete and accurate?
Is the approach, experimental design, review or statistical analysis appropriate?

Organization and Style:
Is the paper a description of an experiment or concept or a synthesis of previous work?
Is the paper well written and organized?
What is the hypothesis, objectives or goals put forth?Are all the tables and figures necessary?
Can the paper be shortened?

Evaluation:
Are the interpretations of data and results justified?
What are the major conclusions? Are they significant? Are they interesting? What remains answered?

Your reactions:
Did you gain something from the paper (be specific)?
How does the paper relate to other topics discussed in class?Are such questions and/or methods relevant to your own research?

Two great science communication tools for conferences and teaching: smart screens and cell phones

Two great science communication tools for conferences and teaching: smart screens and cell phones

A few weeks ago at the European Geosciences Union in Vienna I learned about two dead-easy and great science communication tools for conferences.  These are great for any conference hall or meeting, but could be just as easily be used in the classroom to make a more exciting in class research presentations. For better or worse, most of us are carrying them (or looking at them!) right now: a smart screen or cell phone.

The EGU conference uses smart screens in their innovative PICO (Presenting Interactive COntent) sessions. Every PICO author first presents orally in a 2-minute science blitz and then has a smart screen pre-loaded with a dynamic presentation to discuss further with colleagues. Simple and effective.

pico

Jan Siebert (University of Zurich) showing off just how dynamic PICO sessions are.

While I was a traditional poster session, Hannes Müller Schmied of Frankfurt University pulled out his cell phone to show me some additional visualizations (in this case global hydrologic model results posted on their website – this was connected to his poster with a QR code!). It was great to for him to be able to walk me through the results right there rather than be limited by the static images on his poster. We immediately realized this should be called micro-PICO!

micro-pico

Hannes Müller Schmied showing off model results in this micro-PICO session with his poster in the background.

Thanks EGU for teaching me about two super simple and effective science communication tools, which I hope will cross the pond to AGU and other meetings.

What busy profs would like to read in a blog post about active learning

What busy profs would like to read in a blog post about active learning

During a great workshop today on active learning in engineering at McGill I asked two questions (using Socrative) , of the audience. Here is a summary of 24 answers I received:

1) I would like to read blog posts about:

  • activities for large classes (18% of people)
  • activities for small classes (30% of people)
  • technology in active learning (22% of people)
  • wacky or creative ideas for active learning(30% of people)

2) I might read a blog post about teaching and supervision if…

  • It takes into account the sheer lack of time and resources for preparation; ie quick and easy ideas to engage a bored class!
  • it was linked through twitter
  • It was regularly updated and interesting!
  • It does not take too long
  • it helps me achieve better my teaching objectives compared to my current teaching practice
  • It related to economics / social science a bit
  • Its short and introduce tips and examples
  • It gives concrete practical examples of activities for teaching and making students more active
  • I was interested
  • I knew where to find it
  • It dealt with distance education
  • they talked about encouraging creativity and critical thinking
  • it was about new and creative strategies that I can use in my class
  • it included the occasional evidence-based pieces that demonstrate real impact
  • Give ideas about how to get the students more active
  • It’s concrete, thoughtful and provides ideas
  • it was relevant and to the topic. I also would like to see it promoted within the departments to encourage conversation about teaching and learning
  • It is useful

My summary is that people want to hear about all types of different aspects of active learning and they would be motivated to read posts if it interesting and provided something useful.

Thanks Michael Prince of Bucknell for the great workshop and Milwaukee Mag for the image.

Surprises and lessons learned from co-teaching an inter-university graduate course

Surprises and lessons learned from co-teaching an inter-university graduate course

GrantFergusonContributed by Grant Ferguson, University of Saskatchewan
grant.ferguson@usask.ca

 

In an earlier blog post, Tom discussed some of the advantages and disadvantages of co-teaching a blended graduate course to students at McGill University, the University of Wisconsin – Madison and the University of Saskatchewan. This course wrapped up last month… we definitely learned a few things during its delivery, some of which were surprises that we hope you can learn from.

Surprise #1: The course outline and structure came together rather quickly and there was minimal debate on the content that we would cover. We did not attempt to be comprehensive in our coverage and chose to teach to our research interests. At the same time, we did not feel that there were obvious gaping holes in the curriculum. We included a review of what we expected the students to understand coming into the course. Although we were teaching students from a variety of backgrounds including civil engineering, environmental science, geosciences and forestry our expectation was that everyone should have been exposed to similar content in their undergraduate hydrogeology course. A recent review on the content of undergraduate hydrogeology courses by Gleeson et al. (2012) indicated that the core content of these courses does not vary that much from university to university.

However, surprise #2: students had very different interests and strengths. Some universities had students that excelled at MatLab while others were far more proficient with GIS. The interests of students also tended to mirror those of their home institutions. Students from McGill tended to be interested in water resource sustainability and large-scale problems, students from Saskatchewan were focused on problems associated with resource-extraction and students from Wisconsin tended to be more interested on hydrological processes and ecosystems. Exposing these biases, strengths and weaknesses was valuable for both instructors and students.

Surprise #3: this may not be a more ‘efficient’ way to teach since we spent far more time preparing lectures for this course than we normally do for other courses. Teaching to students and other universities with other instructors present brought teaching to a different level.   This effectively negated the initial thought that this would be a more efficient way of teaching because we were only on the hook for a third of the lectures. Part of this preparation was related to knowing that we would be forced to rely on slides more heavily than in a conventional classroom. However, the greater motivation was knowing that this presentation was going outside the walls of the home institution and that colleagues from other universities would be following along.

Surprise #4: Communication during the course went more smoothly than expected. Aside from a few momentary hiccups, there were few problems hearing the lecturer. Talking between institutions during the lecture went well, although questions were generally repeated by the lecturer or someone nearer to the microphone at other schools. The biggest obstacle might have been for the lecturers. Despite some efforts to situate cameras and explore different views within Microsoft Lync, it was difficult for the lecture to see the remote classrooms. Without being able to see facial expressions or body lan20140325aguage, it was difficult to assess how the material was being received at the other locations. This problem can likely be resolved to some extent with additional monitors and better cameras.

The feedback from the students was largely positive. Most of them seemed happy to participate in this experiment and get some exposure to other institutions. Tom, Steve and I all agreed that we would do this again given the chance. However, it appears that the stars might not align for us in 2015 due to some other commitments. We will see if we still feel this way in 2016.

Re-posted on Inside Higher Ed blog.

Active learning in large classes: a gallery ‘walk’ with a 100 students

Active learning in large classes: a gallery ‘walk’ with a 100 students

Active learning in large classrooms is difficult but not impossible – here is one example of an active learning technique developed for small classrooms, the gallery walk, which I have successfully re-purposed for a class of 100 (but I see no real upper limit on class size with the modified version of this activity).

“In Gallery Walk student teams rotate to provide bulleted answers to questions posted on charts arranged around the classroom. After three to five minutes at a chart or ‘station’ the team rotates to the next question. Gallery Walk works best with open ended questions, that is, when a problem, concept, issue, or debate can be analyzed from several different perspectives.” SERC Pedagogy in action

20140325_bigclass

Teaching a large class. Photo by Maria Orjuela-Laverde, courtesy of Faculty of Engineering, McGill University

In most large classes in auditoriums, there is not the time or space for students to actually walk around the ‘gallery’. So instead I bring the ‘gallery’ of four provocative questions to groups of students on clipboards that are rotated around the classroom :

  • the class is split into four quadrants which are further divided into four groups (so ~5 people per group for a class of 100). Each group starts with a clipboard with one of the four questions and the four groups in the each quadrant should have the four different questions (good to check before starting).
  • Students are given 5-10 minutes to respond to the question on their clipboards and then clipboards are rotated until each group has answered each question. Students can constructively respond to previous groups answers to the same question.
  • After four rotations each group should have the question they started with and I ask a few groups to report out a summary to class which I synthesize on the board. In my case we end the activity with a vote of the ‘world’s biggest water problem’.

I find this an excellent way to start and/or end a term. In my case I teach a rather technical undergraduate engineering class about hydrology and water resources – this is an excellent tool to encourage students to think very broadly and creatively about the topic before and/or after we learn technical details.

This activity was inspired by conversations at the ‘Cutting Edge’ Early Career Geoscientist workshop in June 2012 College of William and Mary, Williamsburg, VA. The workshop is sponsored by the National Association of Geoscience Teachers (NAGT) with funding provided by the National Science Foundation Division of Undergraduate Education. I thank the workshop leaders, NAGT and NSF for this opportunity and encourage other early career geoscientists to check out future workshops.

Co-teaching a blended class across universities: why? and why not?

Co-teaching a blended class across universities: why? and why not?

This term I am co-teaching a graduate class in advanced groundwater hydrology with Grant Ferguson (University of Saskatchewan) and Steve Loheide (University of Wisconsin – Madison). In co-developing and co-delivering this course we have learned a lot – I’ll start here with our initial motivations and write later about our pedagogic decisions, software tools and reflections after the course. It is mostly win-win for students and professors, but I’ll describe some of the disadvantages below.

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Teaching in an active learning classroom. Photo by Owen Chapman, courtesy of Faculty of Engineering, McGill University

Instead of being a MOOC, the course is a SPOC – a small, private, online classroom. Students and professors simultaneously meet in real classrooms at each university and connect as a video conference. Students collaborate on projects across universities and each professor leads instruction for part of the term and participates in all classes. We use a variety of software tools for blended learning including polling (socrative), content management (wikispaces), and video conferencing (microsoft lync).

Students are exposed to topics, tools and skills they would never learn in a regular classroom. Probably most importantly, students learn about varied topics that would not normally be covered at their university. One idea that has worked well is focusing on cutting-edge research ideas and techniques including research ugly babies that are not often discussed in the literature. They learn to collaborate internationally using virtual tools. And they develop an international professional network spanning multiple universities.

A  number of students have said ‘wow, it’s like three courses in one!’ and as instructors we have noticed there is not lull in the middle or end of term where students and/or instructors are tired of the course, tired of each other, or just tired. Instead it is just on to the next topic and instructor.

Many of the same advantages are true for the instructors: we learn new ideas from the other instructors, we collaborate internationally in co-developing and co-teaching this course and we expand and enrich our professional network. And we share the teaching load.
You can probably guess the two main disadvantages: the software tools are not perfect and interaction between real classrooms can be stilted. Both are true and we were very honest and clear about this with students from the start:

20140325_expectations

Almost every class there has been a minor glitch with the audio or video but it’s always been minor problem with a reasonable solution – with the myriad of ways to connect today there are many plan B options.

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Connecting with other classrooms using video conferencing. Photo by Owen Chapman, courtesy of Faculty of Engineering, McGill University

During our weekly class time, interaction between individual students in different real classrooms is difficult. During class time, most of the interactions are between students and the lead instructor or between students in the same real classroom during an active learning activity. But outside of class time, students interact via discussion on the content management system and collaborate on projects using skype, google chat etc.

So far, co-teaching a blended graduate class across universities has been a win-win for students and professors – I’d be happy to hear about other SPOC classes.

Re-posted on Inside Higher Ed blog.

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