How I teach… Arid Environments

Why do I teach Arid Environments?

Many UK schools and teachers do not teach Hot Arid Environments at any Key Stage. It is easy to see why: many of our students have no direct experience of them, and familiarity with the landscape is always perceived as helpful. We tend to teach that which we know in the UK instead: rivers, coasts and hazards, and if we want a touch of the exotic, we might do Glaciation and Ice!

And yet, I’d argue that Hot Arid Environments are critical to our understanding of the planet and key environmental issues, and the teaching of them is much simpler and more accessible than many people think they are. I hadn’t ever studied Deserts until I started teaching – despite working with some notable figures in Arid Geomorphology at university – and it wasn’t until my first year that I started to work with them, and see how they worked.

Now, they are among the most popular of units for my A Level students. I think part of that is that it’s genuinely new and exciting – it’s hard to get interested and enthusiastic about the third time you’ve done coastal engineering – and part of that is that deserts have a logic and satisfying “ahh” to their understanding. You can “get it” quite quickly – and make sense of something which hitherto looked incomprehensible and alien. I think we often underestimate how powerful that can be in terms of motivation and satisfaction for our students.

In this article, I’d like to talk about some big ideas involved in teaching of them: and explore the key concepts, the key strategies and the key misconceptions in setting up the teaching of Arid Environments for the first time.

Key Concepts:

Most Hot Arid specifications cover the same concepts in terms of big ideas and topics.

  1. How do deserts form?

For most topics, this is the “distribution and cause” section. You are normally asked to define aridity (either rainfall, or aridity index), describe the distribution of deserts across the world, and see how they are different and show a full range of environments. Often, this links to environments and biome distribution from before, together with the opportunity to do climate graphs and interrogate the type and nature of the climate. Doing this – building from very familiar skills and components – is one of the key strategies here: to help students feel confident as soon as possible with the material. In some specifications, this can lead in to ‘charactersitics’ of the climate: concepts like diurnal range, seasonal temperature variation, katabatic winds and wider salinity, together with the basic idea of water availability and the potential for that to be very seasonally significant.

This is also a good opportunity to get involved in the ‘scale of aridity’ conversation, and introduce early the idea that not all deserts are the same: varying in terms of levels of aridity, or foundation geology and type (erg, hamada, reg). This is a key theme that we want to emphasise during the course – it’s an excellent “it depends” for evaluative essay writing at the end.

A close up of a map

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The next component of this unit tends to look at what factors cause deserts to form. Early on, we want to be clear that the “formation of a desert” isn’t the same as “desertification” – we want to avoid that misconception later. Typically, we’ll look at the big scale (e.g. pressure/wind patterns, Hadley Cell causing constant aridity) and the contributory factors (e.g. continentality and local wind patterns, cold ocean currents, and the rainshadow effect. Like any physical process, this is about linking cause and effect with clear diagrams; and then looking at examples to explore how they combine and make deserts worse. It’s interesting to define plenty of desert examples, and look at which bits are caused by what.

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It’s helpful to start structuring that environmental discussion, and show the concept that hyper-arid deserts are the ones which have multiple factors of aridity, rather than just one. Again, thinking structurally about “which is the biggest factor?” or “which is most important?” or “is continentality the most important?” helps them to think about how this will work and how they would evaluate the factors.

2. How do deserts work to produce a landscape?

Often, this is the component of the teaching that people feel less comfortable with, because there are lots of landforms and strange terms to get used to.

Again, start with the familiar. “Geophysical fluid dynamics” is a really fancy way of saying that all fluids behave in similar ways, so it’s just like rivers, in a lot of respects. Deserts are shaped by a combination of three things: the wind (Aeolian processes), modern water (running water) and water from a past time (Pleistocene) when it was much wetter (pluvial period) because of major climate changes (Pleistocene pluvials). There are some very accessible introduction clips from things like Professor Iain Stewart’s Power of the Planet which shows the changed conditions really nicely: and shows the flow and shape of the landforms. It’s sometimes a fun exercise to show some landforms and guess “water or wind” – and it can occasionally be a nice stretch to include non-Earth landscapes (e.g. here, with Martian sand dunes).

Once we have established the origin of the process, we can look at what they do. Like our rivers, processes tend to have desert parallels: there is erosion, transport and deposition. One of my key tactics is to say “what do we expect from rivers?” and look at why it’s the same or different. So, for example, there’s no ‘solution’ transport because we can’t dissolve sand in to air like we can in to water.

The core processes of weathering, erosion, transport and deposition can be split up in to “fluvial erosion” vs “Aeolian erosion”, and I tend to try and group my teaching of the various landforms in to categories to help their thinking along. I’ll teach all of the Aeolian landforms together, and then try and connect them up as a ‘landscape’ – showing how deflation/erosion, transport and deposition connect up to produce the big picture of the desert.

For water, the modern water landscape connects up through wadi and high mountainous regions, out on to the intermontane basin/salt lake environment. For many students, the direct parallel to the long profile of the river, and the connection to how that all fits together makes a lot of sense, and it’s a strong landscape to review and explore.

The biggest challenge is normally the “past water” environment: conceptualising the magnitude and time scale of the erosion processes to produce a dissected fluvial landscape is absolutely alien. Here, I find that a clearly drawn diagram showing the evolution of the landscape, and then connecting that to specific panorama/analysis and views of the key examples (e.g. Monument Valley, Utah) on Google Earth, tends to overcome the conceptual blocks.

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  • How do things survive in the desert?      

Adaptations to the desert are probably the best known and simplest to teach of all of the core desert units. In part, this is because they’ve done it a lot in Biology/similar, and the idea of adaptations is not too alien. There are often direct conversations about net primary productivity and measures of biodiversity and processes, or physiological adaptations versus behavioural adaptations.  

In part, I think it’s because many of the adaptations are very memorable and specific – and although there *can* be a lot of technical vocabulary to come to terms with, the evidence of adaptation and what is involved is quite simple and self-evident. There are some excellent YouTube clips of specific animals (shovel snouted lizard dancing, sidewinder snakes attacking, and desert foxes prancing), and pictures of baby camels always generate an ‘aww’.

This is a great opportunity to reinforce some prior learning: what are they adapting to? What are the climate characteristics that cause the problem? Is it the same for all? What deserts are easiest to adapt to, and why? Which deserts are hardest to adapt to, and why?

  • How do we manage the desert?

The final component of most topics looks at desertification and how we manage deserts. This is one of the most complex issues to solve, and being able to unpick the variety of causes and complicating factors often overlaps significantly with human geography course components. Many students quite welcome the chance to be back on the familiar ground of “management”, and the classic top-down vs bottom-up debates that they are accustomed to in development conversations. Again, the emphasis on “what kind of desert?” and “what level of development?” tend to be quite helpful in framing and debating some of the bigger evaluative issues involved. This is a nice way to review the unit, and come back to real people and real lives.

Key Teaching Strategies:

For me, the first teaching strategy is obviously to know the material. With deserts, this is particularly key for teachers: particularly if you’ve never learned it explicitly yourself. Often, this is a case of reviewing and brushing up on some knowledge in various places, so you may want to go to different places to have a look at these ideas. The Dictionary of Physical Geography is a technical reference guide that can be invaluable, and Waugh’s classic “Integrated Approach” has a very good reference section for Deserts that rings very true at the macro scale.

Elements of certain shows (e.g. Power of the Planet, How Earth Made Us, both by Prof Iain Stewart; natural world programmes like Planet Earth) can be great for specific processes, or visualising key adaptations and responses.

In terms of specific teaching strategies, I find the following considerations to be helpful:

  • Connections to previous knowledge and physical processes: making the specific links between their familiar knowledge (like rivers, or atmospheric processes) and the unfamiliar application of these processes to the arid environment is really helpful. You can extend this by questioning and exploring the similarity/difference – why is the water more powerful *here*? Why is this more effective than in rivers? Why is this more critical for a desert?
  • Landform Analysis: I teach using a template (4S/PEN), which allows students to look for the same things and components in every landform we do. This gives a frame of reference for descriptions (the 4xS components of Shape, Size, Structure, Situation/Site) and the explanation of process (Process, Explanation, Normality). The use of this approach allows them to understand that we can look at all landforms in the same way, and have confidence in saying *something* about an unfamiliar landform or feature. Like every landscape and physical geography process, there’s a need to be able to sketch and explore the landscapes.
  • Grouping “landscapes” vs “landforms” helps to connect up the big ideas in their mind, like upper/middle/lower course in the river. Again, this is about structures for me: how do I set up the teaching, so I do a bunch of things together, talk about how they connect – maybe even do a past question or consolidate that, and move on. It’s important to plan the ‘blocks’ in advance, and to know what kinds of themes are normal for your specification. For me, the questions are inevitably themed around “process” – so aeolian versus modern water versus past water. By grouping my teaching of landforms in those groups, I create the schema of learning in the students’ minds as I’m going along – I don’t then have to make sense of it later!
  • Frame your teaching around the debates: on a very similar theme, the big ideas in desert management, or in desert adaptation come in “themese”. It might be magnitude/frequency, it might be human/physical causes of desertification, or top down/bottom up analysis of management. If part of your spec is evaluating outcomes, then help them think and structure the scale of the debates by the way that you teach it.

Realistically, though, the advice here is utterly no surprise to anyone who has taught any kind of physical themed unit before: it’s the same principles as you’d normally offer!

Key misconceptions:

Arid environments are “desserts”: just stop it. Don’t even let it crepe in to the start. It’s not to be trifled with. Know your roll. I could keep doing this…

  • All deserts are the same/ All deserts look like hyper arid environments: The key here is to show variety in your images, videos and sources. Show rocky deserts, not just sandy ones. Show semi-arid environments with vegetation, show the change and the seasons where you can. Try to avoid the same-looking clips and pictures, and the stereotypical dune/camel/Sahara sand imagery… deserts are huge and varied, and this is a massive evaluative point at the top end of essay analysis!
  • Desertification and the formation of deserts are caused by the same things. This tends to creep in towards the end: when you start looking at desertification, and students talk about the Hadley cell. It’s important to try and emphasis the role of “formation” versus “degradation” and show the changes wherever you can.
  • Confusion over Aeolian vs fluvial landscapes: quite a difficult one, because ultimately this “equifinality” concept means that they look really similar if you. Teaching in blocks and chunks is key to building conceptual understanding, and then exposure to a lot of different sources and practice questions helps to build confidence with analysis and interpretation of sources.
  • Confusion over types/scales of water: again, this is just about practice and getting used to the *scale* of a desert landscape. Familarity with different things and examples helps here!
  • There is a solution to desertification… can sometimes be a difficult concept for students in the management components. Critical evaluation is vital: will the Great Green Wall ever really work in a poverty-ridden complex scenario like the Sahel? Really? What makes you believe this to be the case?

In an ideal world…

Deserts fieldwork can be some of the most awe-inspiring opportunities to show the world in a different light to your students. While lots of the formerly travelled North African experiences (Tunisia) might be off your list for now, Morocco is still well loved by UK fieldwork travellers. There is a huge range of desert landscapes available close to Europe, but you do end up having to drive quite a lot between sites.

Further afield, Jordan and the Middle East offer exceptional adventure – but there’s an obviously high cost; and the same can be said for West Coast USA. I’ve had really positive experiences with a few agencies and companies offering potential trips – and we used a major provider to run tours through Tunisia for years before the Arab Spring!

If anyone wants to fund me to come along as a consultant…

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