The duality of wetlands in drylands: deluge and drought

Thursday 3rd August 2017

The 2nd Wetlands in Drylands (WiDs) meeting took place at Macquarie University in Sydney, Australia, between 24-26th July 2017.  Organised by Tim Ralph, the meeting involved presentations and breakout group discussions, and was followed by a four-day excursion to the Macquarie Marshes in inland central New South Wales.  Following on from the inaugural WiDs meeting held near Parys, South Africa in November 2014, a meeting that led to formation to formation of the Wetlands in Drylands Research Network (see, this post is an attempt to cast a perspective over the activities.  The activities provided an opportunity not only to assess progress in wetlands in drylands research since the Parys meeting, but also to place these activities against the backdrop of more than two decades of research and management in the Macquarie Marshes in particular.

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Tim Ralph giving the opening address at the WiDs 2017 meeting at Macquarie University (Photo: Will Farebrother)

A day-by-day outline of activities at Macquarie University is provided elsewhere (see  Stepping back a little, it is noteworthy that compared to the Parys meeting, which was specifically for 16 UK and South African wetland researchers alone (this was a stipulation of the catalysing funding scheme), the Macquarie meeting was larger (~50 attendees) and more diverse.  A common lament at the Parys meeting was the absence of involvement from other people whose social and professional lives revolve around wetlands in drylands (e.g. representatives of local community groups, subsistence and commercial farmers, wetland managers and policy makers).  Most wetlands in drylands are living and working landscapes, such that the relatively new term ‘social-ecological system’ can be readily applied.  While blue-skies wetland research remains important, in many instances this can benefit from, and dovetail with, additional perspectives.  But thanks to Tim’s sterling organisational efforts, the Macquarie meeting and the associated excursion was blessed with inputs not only from wetland researchers spread across four continents but also from additional constituencies: wetland managers and policy makers, wetland landholders, and – importantly – representatives of the Traditional Owners of the Macquarie Marshes (the Aboriginal Wayilwan nation).  As befitted the meeting theme of ‘Dynamic Landscapes’, specialist sessions focused on hydrogeomorphological, biogeochemical and ecological dynamics, and the resilience and sensitivity of wetlands in drylands, but later sessions were set aside to consider the interactions between science and management, and indigenous knowledge and management.

As a consequence of this diverse involvement and structure, discussions following presentations and in the breakout groups were considerably enriched, with particular attention focusing on how best to build and maintain strong relationships between scientists, managers and other stakeholders to address the many challenges facing wetlands in drylands.  What are the main barriers to, and opportunities for, communication and sharing of wetland knowledge and insights?  How best can wetland researchers translate findings into forms that can be assimilated by wetland managers?  To what extent should management concerns help to shape wetland research priorities?  Can environmental water flow releases from reservoirs work in synergy with ‘cultural flows’ to enable maintenance of local customs associated with water (e.g. fishing)?  And how can cultural perspectives on wetlands – oral histories and the like – be dovetailed with scientific perspectives?

The excursion – dubbed the ‘Macquarie Marshes Research Outreach Event’ – provided an opportunity to continue such discussions in a specific field setting.  This is one of Australia’s iconic wetlands in drylands, known especially for its diverse aquatic and semi-aquatic habitats that occur amidst the otherwise dusty, semi-arid plains of inland New South Wales.  Internationally, these wetlands are best known for their periodic profusion of waterbird populations, which in large part led to their 1986 listing as a Ramsar Wetland of International Importance (  Fed largely by seasonal rainfall gathered in its southern headwaters, historically the Macquarie River flowed freely northwest and north past towns such as Wellington, Dubbo and Warren, eventually disgorging its water and sediment amongst a confusing tangle of active and abandoned channels, marshlands, swamplands, floodplains, woodlands and lagoons.  In particularly wet years, the extent of flood inundation could expand to around 3000 km2 (300 000 ha) – an area roughly fifty-five times the size of Sydney Harbour or 1% of the total area of the United Kingdom – only to shrink back to much smaller areas of more-or-less permanently wet, ‘core wetlands’ during drier years.  Such a wetting-and-drying dynamic is the natural norm in inland Australia’s highly variable climate, and is associated with a well-adapted boom-and-bust ecology.  The local Aboriginal peoples would have known these rhythms well, adapting their cultural practices accordingly.  But European explorers and colonists took far longer to appreciate them.  In 1818, John Oxley arrived at the edge of the marshes in flood and turned around, concluding that he had arrived at an inland sea.  A decade later, Charles Sturt came during a drought and found largely dry floodplains, albeit ones dotted with small waterbodies, concluding instead that only in very heavy rains could the marshes and adjacent lands be inundated.  Even with the benefit of nearly 200 years of collective hindsight, fleeting visits still colour many people’s perceptions of the value of wetlands in drylands.  The marshes offer a very different personal experience in a wet year compared to a dry year, but both are needed for a fuller comprehension of the system’s workings.

2 middle Macquarie River

Winter low flows in the middle Macquarie River between Dubbo and Warren (Photo: Stephen Tooth)

3 Marshes wet & dry 2008-2010

The southern part of the Macquarie Marshes Nature Reserve in times of drought (late September 2008) and flood (late November 2010) (Photos: Tim Ralph)

And like many other wetlands in drylands around the globe, the absence of this longer-term perspective has been partly culpable for a steady decline in the health of the Macquarie Marshes, whether this be measured in terms of tree deaths, reduced diversity of vegetation and fish communities, or declining waterbird numbers.  Upstream dam construction and associated flow regulation, urban and agricultural flow extractions, and creeping encroachment from irrigated lands have all taken their toll on the marshes.  To this toxic mix, add complications from river and floodplain engineering schemes, marsh-dissecting roadworks, and greater flow variability resulting from climate change, and their declining health should come as no surprise.  In short, apart from a few areas of the marshes where inundation is now more-or-less permanent (and somewhat ironically can result in tree deaths and adverse soil geochemical changes), in many other parts, flooding events are now less frequent and less extensive, while desiccation events are becoming more frequent and more severe.

4b swamp stomp compiled

Swamp stomping in Buckiinguy Swamp (Photos: Stephen Tooth)

4a Willancorah swamp

Willancorah Swamp in the southern marshes (Photo: Stephen Tooth)

Roughly 90% of the Macquarie Marshes is now in private ownership, with the remaining 10% in protected areas, most notably the Ramsar-listed Macquarie Marshes Nature Reserve, but even these sorts of designations have not provided immunity from the overall health decline.  The two main portions of the reserve (southern and northern) are not accessible to local people or visitors from farther afield, so many of the deleterious changes that have taken place within the southern portion especially – desiccation, tree deaths, channel erosion, and so forth – have gone largely unnoticed.  In itself, this lack of public awareness is part of the problem.  In a 1992 commentary in the National Parks Journal, Bill Johnson (a former ranger with the NSW National Parks and Wildlife Service) argued that that while there was a need to halt many of the processes contributing to their decline and to begin restoration, the long-term viability of the Marshes is “totally dependent upon the involvement of the wider community in the management of the wetlands and the Macquarie River”.  An Australian Geographic article from March 1996 provided a snapshot of conditions in the marshes, highlighting the rich birdlife in particular, but not shying away from reporting some of the negative ecological changes, including tree deaths, waterbird declines, and the spread of invasive species such as the European carp and feral pigs.  It also sampled a wide range of local community views on the management of the marshes, including a quote from a now-departed local resident: “If people can’t visit the marshes, they won’t care about them”.  In this respect too, personal experience is vital for influencing perceptions of the value of wetlands in drylands.

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The entrance to the dominantly dry southern portion of the Nature Reserve (Photo: Stephen Tooth)

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Mobs of roos within the Nature Reserve (Photo: Stephen Tooth)

Johnson’s commentary and the Australian Geographic article both focused on the key issue facing the marshes, namely the diverse views regarding the provision of water for urban, agricultural, environmental, and cultural purposes.  In a 1998 article in the Australian Geographer, Philippa Brock (then-time member of the Macquarie Marshes Catchment Committee) provided an overview of the declining physical status of the marshes and the evermore complex water allocation and distribution framework that was trying to balance the competing demands.  She highlighted the need for scientists and managers to work together to develop expertise in addressing natural and artificial changes in the marshes, concluding that the best that we could hope to achieve was: “… management of this unique ecosystem in a manner as close as possible to a ‘natural state’.  In an already regulated river system … this may require some degree of intervention and ‘active management’.”

These articles were published during the 1990s when La Niña conditions were still generating moderate rainfall and flooding.  In retrospect, this decade might be referred to as the last heyday of the marshes.  Ecological health worsened dramatically during the ‘millennium drought’ (c. 2001-2010), but has improved slightly in recent years, as a new La Niña phase has led to the return of moderate flows.  Intense competition for water has remained, however, and the policies and practices for water allocation and distribution have undergone further evolution.  So two decades or more later, where do we stand against the views and opinions expressed by an earlier generation of marshes managers and residents?  Has any progress been made against the calls for greater community involvement, and for closer working between scientists and managers?  Has scientific research provide any traction with the issues of negative ecological change?  Have channel and floodplain restoration efforts succeeded or failed?  Are there improved policies to balance the competing demands for water?  And how have local community perspectives fared within the negotiating rooms?

The excursion to the Marshes provided an opportunity for myself and others to ponder these sorts of issues.  And it’s mixed news.  Thanks especially to the work of Tim Ralph, his academic colleagues and students, our knowledge of the geomorphology, sedimentology, and environmental history of the Marshes has improved considerably.  Along with important contributions from other research groups, the links between landforms, earth surface processes, and ecological functioning in the marshes are now much better known, albeit still incomplete.  There is, for instance, much greater cognisance of the intrinsic dynamism of these ‘wandering wetlands’ and how lateral channel shifts, erosion and sedimentation can lead naturally to changes in wetland location and extent, regardless of conservation boundaries (  Suggestions that the degraded and drying southern portion of the Nature Reserve should be abandoned in favour of focusing efforts on the wetter northern portion can be rebuffed with the argument that a longer term perspective is needed: wait for the next lateral channel shift, keep patient during the drought, and wetter conditions will likely return.

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Chewing the fat at Willie Retreat (Photo: Stephen Tooth)

Some of these insights have been implemented in management policies and practices.  Some attempts at restoration of parts of the marshes have failed, even threatening the Ramsar status of the Nature Reserve (see, but lessons have been learned and are being incorporated into management practices (e.g. improving the design of channel-spanning weirs).  Some private landowners are fully on board with attempts to better understanding the landscapes and ecosystems of the marshes, and readily facilitate scientific research efforts.  While the Nature Reserve is still not publically accessible (a decision that seems to be based mainly on attempts to exclude unwelcome visitors such as illegal pig hunters), local community (including Wayilwan) perspectives are now given greater prominence in round-table discussions about the management plans for the reserve and the marshes more widely.

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Discussing the long history of Aboriginal occupation and use of the marshes.  A degraded mound (lower right) provides evidence of a ceremonial site alongside the old Macquarie River (Photo: Stephen Tooth)

Progress on other issues remains unclear, at least to me.  In a short visit of only two full days, it was impossible for me to get my head around the intricacies of the current marshes water allocation and distribution system, let alone its long and complex history.  Each year, many tens or hundreds of thousands of megalitres of water are released from the Burrendong Dam, but this is divided between environmental flows, irrigation flows, by pass flows and so on …. it’s a complex terminology with complex definitions that is coupled with complex demands competing in a complex social web.  All that is best left for others to elaborate on (see  Similarly, local issues of environmental management and social justice can’t be debated and resolved in a few quick conversations: for instance, just when do we intervene – or not intervene – in natural process such as channel abandonment and flow diversion, and how do we compensate those downstream users who may be deprived of water, or inconvenienced by changing flood patterns?  But the main point is that rarely can science and management be divorced from social context and consequence.

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Debating the options for channel and floodplain wetland restoration in the southern portion of the Nature Reserve (Photo: Stephen Tooth)

Even if answers can’t be provided immediately, approaches to a search for solutions can be outlined, at least in theory: namely, the need to facilitate ongoing communication, dialogue, and exchange of ideas between different scientists, managers, local community groups, and other stakeholders.  There is no simple recipe for doing so, but discussions at the meeting and on the excursion provided anecdotes and case studies to highlight at least some best practice principles.  Building trusting relationships by taking the time to listen to people’s views, engaging with environmental education projects in local communities, and organising open field visits such as the Macquarie Marshes Research Outreach Event …. none of these are magic bullets, but they can help lay the foundations for moving forward.  And in the Macquarie Marshes, many of the foundations are there already, not least because there seems to be sufficient shared concern about the future of the marshes for people to be open to ongoing communication.

Maintaining and building on these foundations is a constant challenge.  As discussions in the field, around the campfire, and on the bus home unfolded, it struck me that people within living and working wetland social-ecological systems enter and depart the scene, much like many of the waterbirds come and go with floods and droughts.  Like stately River Red Gums that line the Macquarie River banks, some individuals, families, social groupings and institutions provide continuity across the decades, persisting through cycles of flood and drought and withstanding the changing water allocation and environmental management frameworks.  But like Bill Johnson and others that frequented the Macquarie Marshes in the 1980s and 1990s, many move on or pass away.  Other people take their place, but with each entry and departure, knowledge and wisdom has to be re-learned and trusting, working and social relationships have to be rebuilt.

Of course, such issues are not unique to the Macquarie Marshes.  Institutional policies and practices can provide some sort of inherited memory and learning to enable ongoing progress, regardless of individual involvements.  In environmental management circles, ‘adaptive management’ is now the mantra.  Adaptive management practices acknowledge that despite uncertainty, decisions must be made and actions implemented, but emphasise learning from the outcomes to inform future decision making.  The Macquarie Marshes has its own adaptive management plan (written by Bill Johnson in a new role – see, something that may well be essential in managing for a future that seems to be getting just a little more uncertain with each passing year.  Let’s hope that in two decades or more, a retrospective similar to the one attempted here will provide positive rather than negative commentary on the state of the Macquarie Marshes social-ecological system.


Footnote: I gratefully acknowledge sponsorship from the NSW Office of Environment and Heritage (OEH) and Macquarie University for the Macquarie Marshes Research Outreach Event.  I also thank OEH staff, local landholders and representatives of the local community for their support and participation.  I thank Tim Ralph in particular for additional discussions and suggestions.  While informed by discussions on the excursion, the views expressed in this post are of course my own.

A glossary for the Anthropocene?

Wednesday 9th March 2016

New Scientist recently ran an interesting competition: can we help shape the linguistic direction of the Anthropocene? In the spirit of ‘Landmarks’, a book of terms for natural phenemona, Robert Macfarlane had pondered the words that might belong to this proposed new geological time interval ( What new words will we need to describe the planet in the Anthropocene, and which words will die?

Landmarks coverMacfarlane made some preliminary suggestions for a ‘desecration phrasebook’ (e.g. ‘trash vortices’ to describe the plastic garbage patches that swirl in ocean gyres …. ‘plastic soup’ is another possibility – see and pondered whether we yet have words to describe the rain that falls when a cloud is seeded with silver iodide or the glistening tidemarks that are left on coastlines by oil spills. Had I been aware of the mid-January deadline before it had passed, I might have entered the competition with some suggestions of my own.

But never mind. Given what I think are some rather uninspiring, even obscure, winning entries (‘saltscape’, ‘ghostroost’ and ‘langing’ – for definitions and some other entries, see, and on the back of new terms already circulating (e.g. ‘manthropocene’ –; ‘plastiglomerate’ –; ‘quoquake’ –, here are some other suggestions:

Anthroposcene – the hubbub of debate and activities that loosely revolves around the idea that humanity may have created a new geological time interval. [Nb. this is a term already adapted by at least two Facebook discussion groups – AnthropoScene and The Anthropos.Scene].

Anthroposense – intelligent, intelligible opinions that are expressed about the putative new geological time interval, whether one agrees with a formal definition of a term or not.

Nonthroposense – the polar opposite of the above.

Anthroposcenic – landscapes that have come to be viewed as picturesque (i.e. ‘scenic’) but that actually are in a far-from-natural, highly-altered state (e.g. the reservoirs in the Elan valley of mid Wales – see–january-2016.html). [Nb. in a recent RGS-IBG presentation, this term has been used in a rather different sense by David Matless to mean specific landscapes that have become emblematic of environmental transformation, such as where houses and graveyards have become undermined by coastal erosion, or where buildings and fields have been drowned by rising sea levels. To this alternative definition, one could also add the examples of buildings and fields drowned by rising waters behind human-constructed dam walls (e.g. Treweryn or Elan valleys in Wales), which in turn may have become Anthroposcenic in my sense of the term (certainly not to all, but to some)].

Anthroposore – a variant on ‘eyesore’, to reflect a more-or-less permanent sore, scar or wound on the Earth’s surface and geological record that has resulted from human activities (e.g. open cast mining, or land contamination and water pollution resulting from a legacy of mining activities).

Glasstic load – clastic sediment (e.g. sand- and gravel-sized material) that now contains a significant component of human-made glass (e.g. beach sediments in Aberystwyth – see

Plastic load – as above, but with plastic instead of glass forming a significant component of the clastic sediment.

The Plasticene – an alternative name for the Anthropocene, if the main signature of human impacts on the Earth’s geological record is taken to be a widespread plastic horizon in sediments formed from about AD 1950 onwards. [Nb. this is likely too similar to the already-existing, formal geological term ‘Pleistocene’ for this one to ever stick but, hey, we’re playing with words here].

The Capitalocene – a term that formally acknowledges the fact that the main driver of changes to the Earth’s environment – and potentially its geological record – has been the rampant growth of capitalism.

The Hollowscene – a play on the already-existing, formal geological term ‘Holocene’ to indicate the geological epoch preceding the Anthropocene (or Plasticene or Capitalocene), left forlorn and bereft of meaning and purpose (assuming a formal declaration of the Anthropocene).

And finally, what about some new collective nouns or verbs?

A refuse (a garbage? a detritus?) of gulls – the flocks of gulls that wheel, squeal and squabble at rubbish/trash dumps.

A gangsta of gulls – the menacing squads of gulls that have become too used to human handouts and now hover around and/or stalk people eating at popular attractions (e.g. seafronts).

To be gulled – a mugging by a gull (e.g. food stolen but no personal injury).

If anyone can add to or better these terms, I will be interested to receive suggestions, and might even feature some on a future blog.

Art and science collaborations in an age of change

Saturday 23rd January 2016

“The Anthropocene is up there with Copernicus’s heliocentricity or Darwin’s theory of evolution as one of the most profound shifts in worldview that has emerged from scientific endeavour” (J. Rockström in The Guardian, 17th Nov 2015)

This is a bold claim indeed. But what exactly is the profound shift that is referred to? The Anthropocene (from anthropo– for ‘human’ and –cene for ‘new’) is a term that has been proposed to signify the pervasive role of human activities – air pollution, species translocations, ploughing, mining, damming, dredging and construction, among many others – in influencing atmospheric, biological, and land surface changes. Some of these changes appear to be ‘dominating’, ‘overriding’ or ‘overwhelming’ natural forces, and to be sufficiently significant and permanent to have shaped Earth’s recent and potential future geological record. In short, have we now exited from the Holocene epoch (the present interglacial time division that started around 11 700 years ago) and entered a new geological interval, one defined by humanity?

The answer to this question, and thus as to whether the Anthropocene should be formally adopted as a new, uppermost time division in the geological column, is still subject to vigorous debate. Some geoscientists remain unconvinced of the justification, practicality or utility of a formal adoption (for an extreme viewpoint, see:  Amending the current subdivison of the geological timescale is a slow, contentious business, although a judgement from the International Commission on Stratigraphy is expected sometime in 2016. But beyond geological committee rooms, the answer – whether positive or negative – also has philosophical, ethical and moral dimensions, with implications for debate and practice across the natural sciences, social sciences, humanities and arts. For this reason, use of the term ‘Anthropocene’ in printed literature has seen an explosive rise (neatly charted by Google Books Ngram Viewer) since Crutzen and Stoermer first outlined its geological significance in Global Change Newsletter (v.41, 2000), a short but influential article that prepared the ground for subsequent debate and speculation.

Google Books NgramOne could in fact argue that the term has now gone viral, and perhaps represents just one more environmental buzzword in the zeitgeist; indeed, as geologists Autin and Holbrook ask, is the Anthropocene debate an issue of stratigraphy or pop culture? (see Certainly, the term has now travelled far beyond academia, and commonly features in the titles of popular books, newspaper and magazine articles, and exhibitions. For recent examples of the latter, see:

To provide our own perspective on this rising tide of Anthropocene-related debate, visual artist Julian Ruddock and I recently held a one-day symposium entitled ‘Strata: Art and Science Collaborations in the Anthropocene’ (Aberystwyth Arts Centre, January 15th 2016). The symposium was supported by the School of Art and the Department of Geography and Earth Sciences at Aberystwyth University, and by the Visualising Geomorphology Working Group of the British Society for Geomorphology ( Building on the successful ‘Future Climate Dialogues’ symposium (Aberystwyth Arts Centre, June 13th 2013 – see, over 25 oral, poster and film presentations focused on art-science collaborations around the nominal themes of ‘Earth’, ‘Water’ and ‘Ecosystems/Life’ (few submissions were received for an intended ‘Air’ session).

Pimm strata tweetEven prior to the call for contributions, it had become clear to us that the Anthropocene is already a term that means many different things to many different people. For some, it is a scientific term that carries a precise geological interpretation. For others, the Anthropocene also represents a political project (after all, what better way to make a statement about humanity’s environmental impacts than to name a geological time interval after ourselves?). Many use the term as a convenient catch-all for any form of human influence on the environment, including multifaceted technological and behavioural developments that may not have any significant or lasting geological impact. And for others still, the Anthropocene is less a scientific than an aesthetic event; something to be re-imagined as an affective rather than a scientific fact (see, for example, Davis and Turpin’s edited collection of writings about art in the Anthropocene).Davis & Turpin

Key questions that we hoped to address through ‘Strata’ included: i) how are the arts and sciences exploring these multiple meanings, either in isolation or in collaboration?; and ii) how can we encourage greater art-science collaborations, especially around the Anthropocene theme?

The full programme of events, along with the oral and poster presentation abstracts and the biographies of contributors, is hosted at [nb. the plan is to add some images and sound to the site, depending on contributors’ permissions]. Following an introduction by Julian and myself, Dan Harvey (one half of the respected Ackroyd & Harvey artistic partnership) provided the keynote address, drawing on personal examples from a long history of art-science collaborations in confronting environmental issues. One particular work (Ice Lens) has even graced the front cover of the prestigious science journal Nature Climate Change (March 2012).Nature Climate Change cover 2

Subsequent presentations – both during the day and in the linked evening session – mined a rich vein of art-science approaches, including those using different combinations of visual art, sculpture, film, poetry, writing, sound and music. Intervening discussion sessions and refreshment breaks provided opportunities for questions and debate. Despite the inevitable time constraints – and the unwanted interjections of a drunken interloper who nonetheless slurred one of the more concise but most scientifically-contentious questions of the day (‘Are we now in the Anthropocene?’) – overall the symposium appears to have been a qualified success.Whalley strata tweet 3

How so? The first of the key questions posed above was addressed more than satisfactorily. The range of presentations at ‘Strata’ provided ample demonstration of the plural meanings now attached to the Anthropocene. Many presentations – highly entertaining and informative though they were – made little or no reference to the term’s original geological meaning. Clearly, the Anthropocene has escaped far beyond these confines, and regardless of whether the term ultimately is formalised as signifying the latest interval of geological time, it is here to stay.

The second of the key questions proved less easy to address. Discussion both within and outside of the formal sessions highlighted some obvious difficulties in art-science collaborations. By and large, scientists want to communicate facts, figures, terms and concepts in ways that are as unambiguous and precise as possible. Established scientific conventions dictate how we should observe and describe the world; meaning (‘interpretation’) then follows. By and large, artists tend to see their role as introducing ambiguities and free thinking in their filtering and presentation of material. Rather than operating in a didactic mode, they commonly want to challenge convention; the beholder of the artwork is then tasked with searching for, perhaps even generating, meaning. Of course, such stereotypes can be challenged, and even highly contrasting worldviews are not necessarily mutually exclusive, but the task is to identify ways to identify and pursue shared agendas in order to produce work that is both scientifically meaningful and aesthetically challenging. Ackroyd & Harvey’s work – along with that of other contributors to the symposium – shows that it can be done. Discussions at ‘Strata’ touched on the importance of creativity, intuition and inspiration in art and science practice, and some practical strategies for encouraging interdisciplinary collaborations were outlined. Hopefully, the seeds of some good ideas have been sown in fresh furrows. For instance, could a follow-up meeting be organised as an art-science workshop, with short presentations being interspersed with breakout sessions to encourage blue-skies thinking and creative collaborations? Could fieldtrips be used to inspire creative collaborations? The evening contribution entitled ‘Argae: Writing the Anthropocene in the Welsh Uplands’ provided an example of the possibilities that could result from the latter; four writers and poets (some with science backgrounds) provided very different creative responses to a shared landscape experience, namely a day tour through the Elan valley in mid Wales, where a series of reservoirs, dams and HEP generators serve as highly visible (although likely not long-lasting) symbols of human manipulation of the hydrosphere. Similar tours – perhaps broadening out to incorporate film makers, visual artists and musicians alongside scientists – could pave the way for other creative responses to various human-impacted landscapes.Griffiths strata tweet 2Partway through the day, one contributor had reminded us all of a quote from Leonardo da Vinci (AD 1452 – 1519):

“Principles for the Development of a Complete Mind: Study the science of art. Study the art of science. Develop your senses – especially learn how to see. Realize that everything connects to everything else.”

As we approach the quincentenary of da Vinci’s death, we now have vastly more ways of sensing the world, some going far beyond direct human experience. Yet in the face of a tidal wave of environmental problems, many brought to greater prominence by the Anthropocene debate, we are still scrabbling for the best ways to see, especially the myriad interconnections. Symposia like ‘Strata’ provide glimpses of the possibilities but remind us that a full view has yet to emerge.

10 Reasons Why …. 10 Rheswm Pam …. : 10

Tuesday 22nd December 2015

Blog post 10 of 10 about the geomorphology of Wales. Click on images to view larger version in a separate window. Parallel blog in Welsh at

Reason 10. Successful environmental management needs geomorphological knowledge. Geomorphology can provide a key input to environmental management, including landscape conservation, ecosystem conservation and restoration, heritage conservation and carbon landscaping.

Sgwd GwladusOn account on spectacular natural and cultural landscapes, large areas of Wales have protected status. Collectively, the three National Parks in Wales – Snowdonia, Pembrokeshire Coast and Brecon Beacons – protect an impressive 20% of the country, including landscapes, habitats, and heritage sites ( The National Parks are complemented by other areas with varying levels of protection (e.g. Geoparks, a Biosphere Reserve, Sites of Special Scientific Interest, Special Areas of Conservation, National Nature Reserves) some of which overlap in space. For example, the Fforest Fawr Geopark (established 2005) is contained with the western part of the Brecon Beacons National Park, with some key objectives being to conserve and enhance the geological and geomorphological heritage, including by developing the area’s potential as an outdoor classroom and geotourism destination ( A complex history of tectonic and climatic changes have acted upon the varied lithologies in the area to form a diversity of landscapes and landforms (Reason 2), many of which form drawcards for tourists. The area around Pontneddfechan, Powys, is a case in point, as it is renowned for its high number of publically-accessible waterfalls that have developed on sedimentary strata, such as Sgwd Gwladus (Photo: Stephen Tooth). Although underutilised at present, geomorphology can play a key role in enhancing the tourist experience by providing information about the origins, development and significance of such landforms, and also can contribute to the development of sustainable management strategies for these popular but protected areas.

In National Nature Reserves, geomorphological processes and landforms provide the template upon which the valued wildlife habitats have developed. Some reserves have been established to protect near-pristine habitats, such as the peat bogs, estuary, and coastal sand dunes near Ynyslas, Ceredigion, while others have been artificially created in mitigation for loss of habitat elsewhere, a prime case being Newport Wetlands on the Severn Estuary. In such anthropogenic wetland landscapes (Reason 8), geomorphology can provide a key input to the design of management strategies, which may focus on maximising ecosystem services, including enhancing biodiversity, providing protection from coastal surges, and promoting carbon sequestration.

log jam 3Outside of protected areas, geomorphology can also play a role in developing strategies for restoration of degraded landscapes, including peatlands, hillslopes and river channels. For instance, in the Cwmparc catchment near Treorchy, Rhondda Cynon Taff, ongoing geomorphological research is helping to evaluate proposed sustainable flood management strategies, including the effectiveness of using engineered log jams to slow flood flows along heavily modified channels (Photo: Stephen Tooth). Geomorphology is also providing key inputs to the design of the coastal defence schemes that are being implemented along many parts of the Welsh coastline, such as at Borth, Ceredigion, where an artificially-constructed reef, rock groynes and breakwaters, and beach nourishment are parts of an overall strategy to protect properties from extreme coastal storms and longer term sea level rise (Reason 9). With mounting concern over habitat loss and likely future increases in the frequency and magnitude of geomorphological hazards (e.g. intense rainfall, river flooding, coastal surges), such trends are likely to continue in years to come.

Did you know? The importance of embedding geomorphological knowledge in environmental management sometimes only becomes apparent where engineering schemes and management strategies have failed. A classic example is provided by a reach of the middle Ystwyth River near Llanilar, Ceredigion. In 1864, the naturally meandering, gravel-bed river was artificially straightened to run adjacent to a railway track but historic maps show that meanders re-established during the next 100 years. In 1969, an artificially straight channel with a trapeizodal cross-section and flat bed was again engineered but without any bank protection works taking place. Within a few months, following a period of high winter flows, the channel had again transformed into a meandering channel with a more irregular cross section. Numerous gravel bars and pools had established along the bed and steep, vertical banks had formed locally (Source: Lewin, J. 1976. Initiation of bed forms and meanders in coarse-grained sediment. Geological Society of America Bulletin, v.87, pp.281-285). The local river authority made further several attempts to re-straighten the channel but such efforts also failed, and ultimately the authorities engineered a meandering channel. This example shows how a variable flow regime that responds rapidly to rainfall, a mobile gravel bed, and unstable banks can combine to give rise to a naturally dynamic, sinuous channel that confounds engineering efforts to artificially straighten and confine its course. In mid Wales and farther afield, this combination of factors is not uncommon (e.g. see Reason 4 and Reason 5). Nonetheless, the lesson seems to be a hard one to learn, for throughout Wales, there are numerous examples of channel re-alignment and bank protection schemes that have failed owing to an inability to take full account of the underlying geomorphological processes.

10 Reasons Why …. 10 Rheswm Pam …. : 9

Monday 30th November 2015

Blog post 9 of 10 about the geomorphology of Wales. Click on images to view larger version in a separate window. Parallel blog in Welsh at

Reason 9. The Earth’s landscapes are becoming more hazardous. Both global environmental change and human activities are increasing the magnitude and frequency of geomorphological hazards, which occur wherever and whenever land surface stability is affected and adverse socio-economic impacts are experienced.

Throughout Welsh history, various geomorphological processes – many of them related to extreme events – have represented hazards to local communities. Being located in the temperate mid latitudes far from tectonic plate boundaries, in recent millennia Wales has been largely unaffected by the various hazards posed by extreme events such as glacial outburst floods, tsunami and volcanic eruptions, while earthquakes are a relatively infrequent occurrence (Reason 2). By contrast, given frequent intense and/or prolonged rainfall, a lengthy coastline that is exposed to Atlantic swells, and much steeply sloping terrain, extreme events such as river and coastal flooding, rockfalls, and landslides are common hazards. While such events may result from entirely natural causes, human factors can enhance their severity, possibly increasing the damage to infrastructure and/or the loss of human lives.

IMG_4450 reducedThe events that took place in the small village of Dolgarrog, Conway, provide a case in point. Following a period of heavy rainfall that had started in mid October, on the evening of 2nd November 1925, the dam wall of the Llyn Eigiau reservoir in the Carnedd Mountains was breached. The breach released water that flowed downstream and then overtopped and breached the dam wall on the Coedty reservoir. Collective failure of the two dams caused a flood that continued along the Afon Porth Llwyd, rapidly cascading down its steep escarpment course towards Dolgarrog. The water and many thousands of tonnes of transported debris inundated part of the village, forming a fan with imbricated (stacked) boulders up to several metres in diameter on the western margin of the River Conwy floodplain (Photo: Stephen Tooth). 16 people lost their lives in the disaster, a figure that would have been much higher had many villagers not been watching a film in the local theatre (Source: Fearnsides, W.G. and Wilcockson, W.H. 1928. A topographical study of the flood-swept course of the Porth Llwyd above Dolgarrog. The Geographical Journal, v.72, pp.401-416). In 2004, a memorial trail was created through the boulder fan, and this serves as a sobering reminder of the lasting impacts that such extreme events can have on local communities.

On 21st October 2016, the 50th anniversary of the disaster in Aberfan, Merthyr Tydfil, will also provide pause for reflection. In this instance, a toxic combination of several days of heavy rainfall and negligent management practices contributed to failure of a local colliery spoil tip on the side of Mynydd Merthyr, liberating over 150 000 m3 of water-saturated debris. Some of the debris was re-deposited on the lower slopes of the mountain, but some 40 000 m3 continued as a viscous flow more than 10 m deep, rapidly inundating parts of the village, including the classrooms at Pantglas Junior School. 144 people, the majority of them schoolchildren, died in the disaster (Source:;

IMG_9074 reduced

IMG_9065 reducedAround Wales’s coastline, extreme coastal storms represent some of the biggest geomorphological hazards. Recently, this was illustrated to dramatic effect along the seafront in Aberystwyth, Ceredigion, which was subject to a succession of high tides and high-energy wave events in the winter of 2013/14. In the most extreme event (early January 2014), the ground floors and basements of many seafront properties were flooded, paving slabs were eroded, and large volumes of sand and gravel were deposited across the promenade, roads and car parks (Photos: Stephen Tooth). While many parts of the seawall survived unscathed, in at least one place, the wall was breached, and erosion of the backfill lead to subsidence and partial collapse of a seafront shelter (for an animated 3D laser scan of the damaged shelter, see As a Grade II-listed structure, the building material was salvaged and the shelter later reconstructed, and other parts of the seafront were quickly cleaned up and repaired. While such events are dramatic, and had never before been witnessed by many local residents, they are certainly not unprecedented, for significant damage to Aberystwyth’s seafront also had been caused by extreme storms in January 1938 and October 1927, as well as in earlier decades. Moreover, despite much of the media’s appetite, it may never be possible to attribute any individual extreme event to the impacts of global climate change. But in a world with rapidly rising sea levels, warmer average air temperatures and a more unstable atmosphere, such coastal storms may provide insights into the types of geomorphological hazards that in future may become more common along the Welsh coastline.

Did You Know? According to a Welsh government-sponsored report, 1 in 9 people in Wales live in properties that are at risk of flooding from rivers or the sea. In total, this represents 357 000 people and 220 000 properties (Environment Agency Wales, 2010. Future Flooding in Wales: Possible Long-Term Investment Scenarios. Available at: Many of these properties are located in towns and cities in the low-lying, densely populated coastal areas of north Wales and the post-industrial valleys and lowlands of the southeast, having been constructed when regulations on building in flood-prone areas were lax. With projections of future increases in inland and coastal flood frequency and magnitude, the number of flood-prone properties is likely to increase, with flood management likely to become one of Wales’s most pressing environmental management problems. Some of the impacts of extreme floods are obvious, such as the inundation and damage or destruction of property and infrastructure. Other impacts are less obvious but may be just as severe. For example, in the headwaters of many Welsh river catchments, historical mining activities have led to significant concentrations of heavy metals in floodplain sediments. During extreme floods, many of these sediments are re-mobilised by bank erosion, and then transported downstream and re-deposited on lower-elevation floodplains. This can result in widespread pollution of agricultural land and even domestic gardens. For example, levels of lead, zinc and cadmium locally have been found to be above recognised guideline values, and may pose significant risks to the health of grazing animals (Foulds, S.A., Brewer, P.A., Macklin, M.G., Haresign, W., Betson, R.E. and Rassner, S.M.E. 2014. Flood-related contamination in catchments affected by historical metal mining: an unexpected and emerging hazard of climate change. Science of the Total Environment, v.476, pp.165-180). Such studies show that despite the end of most metal mining over a century ago, its legacy continues to affect the Welsh population. Due to the largely invisible nature, however, this particular geomorphological hazard is often overlooked.

10 Reasons Why …. 10 Rheswm Pam …. : 8

Thursday 29th October 2015

Blog post 8 of 10 about the geomorphology of Wales. Click on images to view larger version in a separate window. Parallel blog in Welsh at

Reason 8. Human activities are influencing landscape dynamics. Increasingly, many geomorphological processes and landform/landscape developments are influenced by human activities.

Across Wales, human activities influence geomorphological processes, landforms and landscapes, both indirectly and directly. Indirect influences include human-induced changes to animal populations or vegetation covers that may have an influence on hillslope runoff and sediment transfer, such as badger control programmes (Reason 2), afforestation or woodland felling. Direct influences include deliberate manipulation of geomorphological processes, and can either enhance natural rates of change, such as by promoting river meander cutoffs as part of channel straightening projects (Reason 5), or suppress natural rates of change, such as through river bank or coastal protection works (Reason 7).

anthropogenic influences

In recognition of the widespread influence of human activities on the Earth’s surface, the term ‘Anthropocene’ has been proposed as a new geological time interval. Have human activities become the dominant influence on the shaping of the Earth’s surface, and if so, will these activities leave an imprint in the long-term, future geological record? In Wales, as elsewhere, vigorous debate surrounds the merits of this proposed new time interval, in part because it is not easy to assess the relative importance of natural extreme events (e.g. earthquakes or rare floods – Reason 2 and Reason 4), internal landform adjustments (Reason 5), and human activities as influences on landform/landscape development and the long-term geological record. Natural extreme events, for instance, can accomplish rapid geomorphic change, perhaps undoing many decades of human engineering and infrastructural developments, as was seen in the winter 2014/2015 coastal storms and floods that damaged many parts of the Welsh coastline (see forthcoming Reason 9). Nevertheless, there is no doubt that many human activities in Wales – indirectly or directly – involve the movement of mass (rock, sediment and water) at rates that vastly exceed natural rates, and in ways that will persist far into the geological future. This is most visible in the case of mining activities, such as Electric Mountain near Llanberis, Gwynedd, where vast quantities of high-quality slate have been removed to leave a terraced hillside that towers above Dinorwic Power Station (upper photo: Denis Egan –, reproduced under Creative Commons licence). Other spectacular examples include the copper mines on Parys Mountain, Anglesey, or the open cast coal mines of the south Wales valleys. Other highly visible human impacts on natural hydrological and sedimentary cycles occur as a result of activities such as dam building, reservoir construction and inter-basin water transfer schemes, as exemplified in the Elan valley, Powys (lower photo: Stephen Tooth), while many coastal areas have been affected by estuary dredging, beach replenishment, and coastal dune landscaping (see ‘Did You Know?’ below).

glass & plastics

Other indirect and direct human activities are far less visible, but nonetheless may still be impacting on geomorphological processes, landforms and landscapes across Wales. For instance, along many parts of the Welsh coastline, a variety of human-made materials such as glass, house bricks, ceramics, metals and plastics now form a small, but perceptible and still growing, component of beach sediments. The long-term significance of these materials, both geomorphologically and in wider environmental terms, is open to debate. Glass ‘pebbles’ recovered from South Beach in Aberystwyth, Ceredigion (upper photo), are relatively benign, as glass is made primarily from commonly-occurring natural elements (mainly silica, sodium carbonate and calcium carbonate). Although persisting in sediments, glass will undergo rapid physical break down under the influence of high-energy or extreme wave and swash conditions. By contrast, many plastics, such as the beads recovered from Whitesands beach, Pembrokeshire (lower photo), are human-made polymers derived from petrochemicals (hydrocarbons). Some plastics will persist in sediments but also may represent a more insidious problem, as it is thought that their physical and chemical break down may facilitate ingestion by marine organisms. In Wales and farther afield, this is leading to fears that plastics are entering the food chain, with as yet poorly understood implications for human health (Photos: Stephen Tooth).

Did You Know? Kenfig National Nature Reserve in Glamorgan is one of the last remnants of a large 3300 ha (33 km2) dune system that once stretched more-or-less continuously along part of the south Wales coastline from the Gower Peninsula in the west to the River Ogmore in the east. Over the last century, however, many of these coastal dunes have been lost to urban, industrial and recreational developments, including caravan parks and golf courses, while others have become overgrown and stabilised by vegetation such as marram grass (Ammophila arenaria). Some estimates suggest that over the last 50 years, 64% of areas of open, mobile sand dunes have been lost from the Welsh coastline as a whole, eliminating the conditions necessary for a variety of rare plants and insects to flourish. These include the threatened fen orchid (Liparis loeslelii), marsh helleborine (Epipactis palustris), the vernal bee (Colletes cunicularius) and the dune tiger beetle (Cicindela maritime). Loss of mobile dunes has occurred even in protected sites such as Kenfig, so in recent years, heavy vehicles have been shifting tons of sand at the site to recreate ‘natural’ dune blowouts and slacks, which are characterised by regular wind disturbance and more mobile, open sand surfaces ( Given Kenfig’s protected status, creating new habitat from the deliberate loss of some existing habitat might raise some eyebrows, but the policy has been deemed ‘destructively constructive’; in other words, a necessary risk to provide the habitat essential for ensuring the survival of rare species. From this example, the influence of human activities on Welsh landscape dynamics can be seen clearly, and both now and in the future, such deliberate earth moving is likely to form an increasingly important part of much environmental management.

10 Reasons Why …. 10 Rheswm Pam …. : 7

Monday 28th September 2015

Blog post 7 of 10 about the geomorphology of Wales. Click on images to view larger versions in separate windows. Parallel blog in Welsh at

Reason 7. Global change is influencing landscape dynamics. Ongoing global environmental change, which includes atmospheric warming and sea level rise, is currently driving landform development, including desert lake desiccation, ice sheet and glacial retreat, and coastline erosion.


Being located in the temperate mid latitudes far from desert lakes, ice sheets and glaciers, some of these landscape dynamics appear to be of little direct relevance to Wales. But sea level rise and coastal erosion is certainly an issue along large parts of the Welsh coastline (see below), and global environmental change is driving other forms of landscape development. For instance, many parts of the Welsh uplands are covered by blanket mires (‘bogs’), which are characterised by peat that is draped across the underlying topography. Mires are major carbon sinks, being formed from partly decomposed plant material that has built up over many thousands of years under typically cool, waterlogged, oxygen-starved conditions. Today, however, many areas of blanket mire are degraded and actively eroding, as seen from Bwlch Y Groes in Gwynedd, one of the highest public road mountain passes in Wales (left photo: eroding mire is visible on the hilltop in the far distance). Mire degradation can be driven by a combination of factors, including overgrazing, overburning, and air pollution but global atmospheric warming is almost certainly playing a role, particularly through subtle changes to upland water balances. A warmer, more variable climate can lead to longer and/or more frequent dry periods, thereby reducing the extent and duration of waterlogging. This enables oxidation of the peat and promotes increased rates of microbial breakdown of the dead plant matter, with some of the solid carbon being converted to carbon dioxide gas. Drier mires are more vulnerable to extreme fires, leading to loss of peat through combustion, a process that also generates carbon dioxide. Drier, fire-affected mires may also be susceptible to gully erosion (right photo), especially during subsequent extreme rainfall events. Gully erosion may be associated with rapid lowering of water tables, leading to further peat oxidation and carbon dioxide generation. Hence, rather than remaining as a carbon sink, extensively degrading and eroding blanket mires may ultimately become a net source of atmospheric carbon dioxide, so adding to the ever-increasing burden of greenhouse gases and providing a positive feedback in an already warming climate (Photos: Stephen Tooth).

Llyn cliff erosion

While a large percentage of the Welsh landmass lies well above sea level (Reason 1), the country nonetheless possesses a lengthy coastline. Much of this coastline is characterised by headlands formed of resistant rock, and intervening bays formed in more erodible rocks or sediments, as exemplified in Pembrokeshire (Reason 3) or along the Llŷn Peninsula. These erodible rocks and sediments may be vulnerable to increased erosion under rising sea levels, particularly if higher seas are accompanied by an increased frequency of extreme storm events. For instance, in Aberdaron Bay, located near the western tip of the Llŷn Peninsula, coastal erosion is pronounced where the 20 m high cliffs are formed in weakly-consolidated glacial sediments that are comprised principally of sand, silt and clay. Erosion of the base of the cliffs is leading to slumping and collapse of the entire cliff face (upper left photo). Along the eastern part of the bay, the cliff is retreating mainly into agricultural land but farther west, the erosion threatens a nearby road, a church cemetery and other buildings. In response to this threat, an elaborate coastal defence scheme has included sea wall construction and chevron-style drainage on the cliff face (upper right and lower photo) (Photos: Stephen Tooth. Aerial imagery from Google Earth, 0.72 km across, with north oriented to the top).

Did You Know? How long is the coastline of Wales? The answer partly depends on the scale of the map that is used for the measurement, as the larger the map scale, the more ‘wiggly’ the coastline appears to be, and so the longer the length that can be measured. Whether measurements are made at high tide, low tide or somewhere in between could also make a difference. Using 1:10 000 maps and measuring along the mean high water mark, mainland Wales’s coastline is said to be about 1317 miles (2120 km) long, while adding the islands of Anglesey and Holyhead increases the figure to 1680 miles (2740 km) (Source: The British Cartographic Society – But with rising sea levels, even that figure may change over time, as some beaches may narrow or disappear owing to inundation or erosion, while others perhaps get wider as retreating cliffs generate greater sediment supply. Around the Welsh coastline, recognition of a rapidly changing coastline is leading to serious debates about future priorities for coastal defence schemes. While some communities have benefitted from extensive investment in coastal protection works in recent years (e.g., there is tacit acknowledgement that not everywhere can continue to be protected, with other communities possibly facing the prospect of abandonment as sea levels rise further (e.g.