The lowest point on Earth

Hywel Griffiths and I recently attended a UK-Jordan workshop on catchment management and water security in Al Kerak, Jordan (23-25th April 2019). The workshop was supported by a grant from the British Council as part of the Newton Fund Researcher Links Programme, and was organised by Jonathan Bridge (Sheffield Hallam University, UK) and Sultan Tarawneh (Mu’tah University). The idea for the workshop originated from a long-standing collaboration between UK partners and Mu’tah University that has addressed catchment modelling and management in central Jordan. Particular focus has been on the Wadi Wala catchment that drains the western Badia Desert and the central highlands south of Amman. The upper 1743 km2 of the catchment was dammed in 2002 to provide irrigation water and function as a managed aquifer recharge (MAR) test site, with the intended benefits of improving drinking water supply to local communities. Since dam closure, however, high sedimentation rates have decreased reservoir capacity by approximately 30%, impacting its MAR performance and prompting substantial new engineering works to raise the dam wall by 15 m.

Water supply issues in the Wadi Wala catchment are emblematic of the wider water challenges in Jordan, which is widely acknowledged to be one of the most water stressed countries in the world. More than 90% of the country has a mean annual rainfall less than 200 mm, resulting in restricted surface freshwater availability and limited aquifer recharge rates, while climate change and rapid population growth – accelerated in recent years by an influx of refugees from neighbouring territories like Palestine, Syria and Iraq – have substantially increased pressures on water quantity and water quality. According to a 2015 joint UNEP and WaterLex report (see, available renewable water resources have dropped dramatically from an annual per capita share of 3600 m3 in 1946 to around 130 m3 in recent years. In addition, short-lived flash floods or longer drought episodes periodically blight different regions, leading to soil erosion, ecological disruption, infrastructural damage, and even loss of human life. So what can we do about this? How can we improve catchment management to improve water security in Jordan? Can we integrate existing and new approaches to water harvesting, wastewater re-use, soil conservation, ecological restoration, river management and so on to achieve this objective?

Hywel and myself had been invited to the workshop on the basis of our previous experience with river and wetland processes, human-environment interactions, and catchment management in drylands. Our recent contribution to the British Council workshop in Argentinian Patagonia (see was also beneficial for identifying parallels and overlap in themes covered by the workshop. A blend of early career and more established researchers from both the UK (7 others, making 9 UK participants in total) and Jordan (11 total) provided complementary expertise in hydrogeology, hydroclimatology, environmental monitoring, water harvesting techniques, irrigation, sustainable water technology, land and soil conservation, among many others.

Welcome and workshop opening at Mu’tah University

Workshop discussions at the Falcon Rock Conference Centre

The workshop was organised in three parts, covering three days. On Day 1, after a welcome from research and administrative staff at the campus of Mu’tah University (located ½ hour’s drive south of Al Kerak), the participants returned to the Falcon Rock Conference Centre for talks from the invited ‘expert mentors’, followed by breakout group discussions to identify areas of mutual interest that might form the basis for project proposals. As one of the mentors, my contribution was a ½ hour talk that provided a global perspective on rivers and wetlands in drylands. The talk highlighted, inter alia, the diversity of dryland river process and form, the role of wetlands in ecosystem service provision, and approaches to management of wetlands in drylands. A booklet from the Wetlands in Drylands Research Network entitled ‘10 Reasons why the Geomorphology of Wetlands is Important’ (see was distributed to participants, along with copies of Tooth and Ralph’s recent ‘awareness-raising’ article in ‘Geography Review’ (2019, v.32). Part of the purpose of the talk was also to contextualise rivers and wetlands in the drylands of Jordan against this wider international backdrop. What are the key characteristics of Jordan’s dryland rivers? Where are the key wetlands in Jordan’s drylands, and is there any legislative protection? What are the ecosystem services provided by these rivers and wetlands and how might the services change in future?

Building on ideas outlined by Grenfell et al. (2014, Geomorphology, v.205) and Larkin et al. (2017, Earth Surface Processes and Landforms, v.42), Tooth and Ralph’s 2019 ‘Geography Review’ article includes a diagram showing how river and wetland processes, forms and associated ecosystem services might be anticipated to undergo change as systems move along an aridity gradient. The diagram hypothesises what might happen to ecosystem services under conditions of reduced flow frequency that results from climate change (e.g. global warming that leads to lower precipitation and/or greater evapotranspiration) but also perhaps from human activities (e.g. abstraction, flow diversion).

One of the images from Tooth and Ralph’s (2019) article in Geography Review (click to enlarge)

But is it a one-way street? Can we envision scenarios whereby rivers and wetlands might move in the other direction towards a condition of greater flow frequency? One of the provocations in my talk was the potential for use of controlled wastewater discharges (i.e. treated used water, or ‘greywater’) to promote more regular flows along sections of normally ephemeral channels, with the aim of enabling within- and near-channel vegetation growth. In both rural and urban settings, this might have a range of benefits, including ecological enhancement, slowing of flow velocities, increased sediment deposition, and promotion of aquifer recharge. This might help provide some level of protection against potentially erosive flash floods and also slow sedimentation rates in downstream dams. But what might be some of the limits to such schemes? Might they just promote riparian monocultures (e.g. reedbeds) with little biodiversity gains and possibly even displacement of native riparian flora and fauna? Might fine sediment deposition under vegetated, slower flow conditions lead to change in bed surface textures, perhaps detrimentally for native fauna (e.g. macroinvertebrates) adapted to living in typically coarse-grained, open framework gravels, as well as having negative implications for rates of aquifer recharge? Might the inevitable decreases in channel cross-sectional area increase local flash hazards? And what might be the consequences of long-term sediment build-up in such vegetated reaches?

As a water scarce country, Jordan is relatively well advanced in the use of wastewater, even being cited as a ‘success story’ of regulating wastewater management in the joint UNEP/WaterLex report ( According to the report, over the last 25 years or so, the number of wastewater treatment plants has more than doubled to around 28, with more than 90% of the treated effluent being re-used in agriculture where it is sometimes mixed with rainwater. But could such treated or blended wastewater be used for the alternative purposes outlined above (e.g. ecological enhancement, flow and sediment control, aquifer recharge)? As far as I am aware there have been no studies in Jordan of the potential benefits or disbenefits – in other words, the ecosystem services or disservices – of using wastewater for these alternative purposes, and no rigorous assessments of the trade-offs involved. Farther west, on the other side of the Dead Sea, ongoing focus is on water quality and human rights issues associated with untreated wastewater discharge in Israel and the Palestinian Territories (, but one of the only studies of the potential geomorphological impacts of wastewater was published nearly two decades ago by Hassan and Egozi (2001, Earth Surface Processes and Landforms, v.26). These authors showed how nutrient-rich wastewater flow from developing urban areas caused rapid shifts from dry ephemeral channels with intermittent floods to vegetated channels with continuous flow, in some instance inducing marked decreases in cross-sectional areas. Surely, there is an opportunity to revisit some of that work and examine other aspects, including the implications for ecology and surface water-ground water interactions?

Plenty of note taking as workshop discussions continue

On Day 2, workshop participants were treated to a field trip around central Jordan. The trip was led by Esraa Tarawneh, and included visits to the Wadi Mujib and Wadi Wala dams, and the Dead Sea. Technically, the Dead Sea is an inland saline lake, with water that is nearly 10 times as salty as the ocean. Owing to diversion of inflowing water from the Jordan River that enters the Sea from the north, the level of the Sea has been falling steadily (~1 m per year over the last few decades), prompting a suite of environmental and infrastructural concerns (see

Overview of the Mujib Dam, located in the bottom of what one owner of a roadside stop has dubbed the ‘Bedouin Grand Canyon’

Overview of the engineering works being undertaken to raise the height of Wala Dam wall by an additional 15 m

A view over the Jordan Rift Valley towards the Dead Sea and the West Bank

Having descended the spectacular eastern flank of the Jordan Rift Valley to park by the side of the road that runs alongside the Sea, we all scrambled down the steeply-sloping shore sediments to the lowest land point on Earth (~430 m below global sea level). Along with the bubbling evidence of subterranean springs, and outcrops of the famous Dead Sea mud (touted by many for its supposed healing properties for skin complaints and physical ailments), there was the depressing sight of the near-ubiquitous plastic trash lines. The lowest point on Earth and surely one of humanity’s lowest points?

The famous Dead Sea mud

Plastic, plastic everywhere …

One of my earliest memories of learning about the place called the Dead Sea did not involve mention of plastics. Instead, it was a photograph in a children’s atlas from the early to mid 1970s that showed someone reading a newspaper while floating in the Dead Sea. This always intrigued me, but even then I think I vaguely understood the concept of salty water having extra buoyancy. Given the limited time available on the field trip, I decided not to investigate these properties personally (although this did mean passing up a golden photo opportunity) but luckily a random tourist was on hand to provide an ample demonstration. And an impromptu investigation of the influence of buoyancy on stone skimming proved irresistible to many on the trip, myself included.  It was hardly an example of controlled experimentation, but some of those stones did seem to skim just a few extra times off the mirror smooth surface.

A tourist in the Dead Sea. And yes, he really was floating …

Delta sediments exposed by the falling level of the Dead Sea

After returning to the vehicle, we crossed over a number of the spectacular ephemeral wadis that periodically disgorge water and sediment into the Dead Sea, sometimes with catastrophic consequences ( In the blazing afternoon sun, we also had good views of the delta sediments exposed by the falling sea level before we ascended the rift flank for the 30 km journey back to Al Kerak and its spectacular stone castle. From the lowest point on Earth and its plasticized cultural low point to what is certainly one of humanity’s cultural high points.

Approaching Al Kerak, with the castle visible on the outcrop in the upper left

Given time pressures and other priorities for the field trip, there was little opportunity for further examination or discussion of Jordan’s rivers and wetlands. On this trip and more generally throughout the workshop, wetlands in drylands remained largely out of sight and out of mind. And in the evening, one of the regular stumbling blocks to raising the profile of wetlands in drylands surfaced. Jordan has two wetlands on the Ramsar list (Azraq Oasis and Fifa Nature Reserve – see, plus undoubtedly numerous other smaller wetlands. But a Jordanian participant insisted that the Fifa Nature Reserve is not really a wetland because it only floods occasionally and isn’t always wet. No matter if it is on the Ramsar list: in their view, the absence of water year-round means that it is not really a wetland. My protests about the need for a more inclusive definition of wetlands that recognizes and celebrates those wetlands that aren’t always wet – the ephemeral, seasonal or temporary wetlands of the world – seemingly fell largely on deaf ears. Coming on the back of similar confusion at the Argentinian workshop ( – scroll down to ‘Wet Places in a Dry Land: Expanding Research into Patagonia’s Desert Rivers and Wetlands’), the growing community of wetlands in drylands researchers clearly has much work still to do.

On Day 3, the workshop again returned to the Falcon Rock Conference Centre, with activities largely revolving around breakout group discussions to identify potential projects to take forward in UK-Jordan collaborations. A range of viable projects was proposed, with most interest crystallising around projects to develop environmental databases, investigate surface water-groundwater interactions, and model climate change impacts on Jordan’s water resources.

Jon Bridge reminding us of the original aims and objectives of the workshop at the start of Day 3

Notes indicating the wealth of ideas to take forward into future activities

At this stage, and amongst this particular group of researchers, it seemed that there was not much enthusiasm for a project to investigate the potential use of controlled wastewater discharges for promoting more regular flows along sections of normally ephemeral channels, and for monitoring the impacts on river and wetland ecosystem services. To be fair, it would be a challenging project to execute, particularly given the need for controlled experimentation and ongoing monitoring over several years (minimum 3-5 years?), most likely using paired catchments. Input from specialists in Jordanian riparian ecology would also be key to the success of any such project. But at least the idea has been sown, and even if it takes some time to grow, may still be worth pursuing in future. In country so water stressed, yet also periodically blighted by disastrous flash floods, it almost seems criminal not to investigate all possible alternative uses and re-uses of the limited water supplies.

Wet places in a (normally) dry land

Sunday 24th March 2019

“Nid oes yma ddwfr croew ond sydd yn sefyll yn llyn ar ol gwlaw, yr hwn ni chefais ddim mwy o hono er pan wyf yma nag a gefais yn y Bala mewn diwrnod lawer gwaith.”  [“There is no fresh water here, except for that which stays as pools on the land after rain, that which I have not had any more of since being here than I had in one day in Bala many times.”]

So wrote William Jones in November 1865 in a letter sent from eastern Patagonia to his family in Bala, north Wales. Around six months earlier Jones had left Liverpool, England, sailing on the Mimosa into the Irish Sea and then the vast expanses of the Atlantic Ocean with around 150 other Welsh men, women and children. With financial backing from a Welsh emigration committee, and the blessing of the fledgling Argentine government, the intention was to establish a new settlement in the largely unmapped Patagonian region. In late July 1865, the emigrants finally reached the Patagonian coastline, disembarking at a location in present-day Puerto Madryn. Having endured considerable hardships during the first few months, in his letter Jones was comparing the rainfall in eastern Patagonia (mean annual rainfall about 200 mm) to the more familiar quantities in Bala (mean annual rainfall about 1000 mm). The lack of regular, extended rainfall in eastern Patagonia came as a great disappointment to the new arrivals, who had been lured from their old homeland with the promise of abundant water and plentiful pastures. But mean annual rainfall figures can be deceptive, and even arid regions can receive heavy bursts of rain every once in a while. And when these bursts come, they can be very heavy indeed, with totals that sometimes exceed 100 mm in 24 hours. In later months and years, Jones and the other Welsh settlers no doubt would have experienced some heavier rainfalls in their new homeland, as would their descendants. Indeed, in the last few years, extreme rainfall has led to widespread flooding in many parts of Patagonia, including in the still sparsely populated central regions of Chubut Province and the main population centres in the east (Puerto Madryn, Gaiman, Trelew, Rawson, Comodoro Rivadavia).

Front cover of the report on the Puerto Madryn floods of 2016

Extreme rainfall and flooding can have negative consequences, including severe erosion and sedimentation, both of which may pose threats to infrastructure and personal property. On 21st January 2016, for instance, nearly 70 mm of rain fell in Puerto Madryn in just 4 hours, leading to widespread flooding and damage to streets, houses, and industrial and commercial properties. But rainfall and flooding can also be beneficial, even essential, for they can help to replenish groundwater and reservoir supplies, and provide the lifeblood for desert ecosystems. Even in normally arid Patagonia, a variety of rivers, wetlands, shallow lakes and springs abound: wet places in a dry land. These wet places – only temporarily wet though many may be – provide a variety of ecosystem services, including water and food supply, promotion of biodiversity, and provision of recreational opportunities. In fact, in otherwise dry lands, the importance of these wet places as delivers of ecosystem service may be disproportionately important. Nonetheless, as previous blog posts have commented (e.g. see and, these ecosystem services are commonly unrecognised or underappreciated, and certainly are rarely managed for optimal or sustainable service delivery. So how do we go about changing this state of affairs?

Providing opportunities for knowledge exchange activities among different interest groups – academics, university students, policy makers, engineers, local communities, school children, and so on – is a good start. And on the back of previous work in Argentina (see and other lines of research, Hywel Griffiths, myself and Gabriel Kaless from La Universidad National de La Patagonia San Juan Bosco (UNPSJB) were able to secure funding for a project through the British Council Higher Education Links Grants scheme. Entitled ‘Wet Places in a Dry Land: Securing Ecosystem Services from Patagonia’s Desert Rivers and Wetlands’, the project funding enabled Hywel and I to visit Patagonia in March 2019 to help run a series of workshops that would include many of the aforementioned interest groups. Coincidentally, and somewhat ironically, the timing of the trip also enabled us to avoid most of a spell of bad weather in Wales but instead experience first hand the capricious nature of the Patagonian weather.

Saturday 9th to Sunday 10th March

It all started well enough. The Saturday morning replacement bus/train journey from Aberystwyth to Birmingham airport was uneventful, and the Birmingham-Frankfurt and Frankfurt-Buenos Aires flights were bearable and on time. Our baggage arrived in Buenos Aires, and arrived intact. The transfer across Buenos Aires to the domestic airport was done in record time thanks to quiet Sunday morning traffic. For once, even the two hour flight south to Trelew left on time. A window seat enabled us to see first hand the aridity of the eastern Patagonian coastal regions, and we marvelled at the hardiness of the early Welsh settlers, many of whom trekked 40 miles south from their point of initial disembarkation to the lower Chubut valley in order to establish the first settlement.

Flying south to Trelew

The flight to Trelew landed on time, and again our baggage was there. Thankfully, we were at the front of the queue for car hire and despite the usual comedy routine of communications about just what was, and what was not, included in our reservation and just why our credit card details needed to taken, we left the airport swiftly. Given the various mishaps and near-disasters that had dogged various stages of travel in our previous visits to Argentina (for example, see, we also left the airport relieved.

A half hour drive west and we were at a house in Gaiman, our temporary base for the next week. Tea and cakes with the owner of our house were followed by a short sleep and shower, both essential for freshening up prior to our first meeting in person with Gabriel. First impressions confirmed what could be gleaned from the previous skype meetings and numerous email exchanges: here was someone who recognized the opportunity provided by the British Council scheme and who had also been working hard to make the workshops a success. We got straight to work with further planning for the week’s activities, and on a breezy night, continued discussions over a meal of milanesa and Patagonian beer in a local eatery.

Getting straight down to work








Designing baseline surveys for the workshop participants


Monday 11th March

Monday’s activities took place at the Trelew campus of UNPSJB, where there was a mixed audience of around 70 academics, students, representatives of government and other decision-making authorities, and other professionals. Before the start of our workshop, we had some hurried meetings with our translator (English-Spanish, Spanish-English), as we knew that she would be essential for ensuring smooth dialogue. Thankfully, email exchanges beforehand had answered most of her and our questions, and we were ready to go.

Crossing fingers and gritting teeth: nervous anticipation by Hywel and our translator ahead of the opening presentation

Pre-presentation activities for workshop participants

Cramming notes ahead ahead of presenting

In a room that seemed to get hotter with every minute thanks to the healthy attendance and the sun that blazed through the single-paned windows onto the blinds, the morning theme focused on flood risk and perceptions. Opening presentations were given by Hywel and myself on flood memories and adaptations among the early Welsh settlers and their descendants, and were followed by presentations by local Argentine researchers on the common mismatch between technical assessments and social perceptions of urban flood and mudflow hazards.

Paula Ferrari talks about past floods in Trelew

Gabriel chairs a plenary discussion

The afternoon theme focused on desert and semi-desert rivers and wetlands and involved a presentation by myself and Hywel that provided a global perspective on these wet places in a dry land, and one by Gabriel and colleagues on the measurement, recording and impacts of extreme rainfall and flood events. Following each set of presentations, there was lots of engaged, rapid discussion in Spanish among the audience, both in the smaller breakout group activities and the ensuing plenary discussions. Plenary discussions were chaired by Gabriel, with the translator helping Hywel and I to keep track of the key points, and it was clear that there was plenty of interest in the Welsh settlement history and the unique historical perspective that this brings to the analysis of environmental change in the Patagonian environment. Furthermore, despite some confusion over the very concept of a wetland in a dryland – a confusion that Gabriel later admitted might have been due to the choice of word ‘humedal’ as a translation of wetland – there was obvious interest in developing more of a Patagonian perspective on desert and semi-desert wetlands.

What do you mean by ‘a wetland in a dryland’? Some confusion is evident

The source of the confusion

Reflection on the first day’s activities


Tuesday 12th March

Tuesday’s activities took place at El Centro Nacional Patagónico (CONICET-CENPAT) in Puerto Madryn, located about 1.5 hours drive from Gaiman. The location had been chosen specifically to ensure wider engagement with academics and researchers based in the city, and around 25 people were present.

The format was essentially a repeat of the previous day’s presentations, activities and discussions, but the smaller, more specialist audience helped to bring a more technical, research-led perspective on discussions. While many similar issues were aired – particularly the complex definition of wetlands in drylands – others were given more prominence than on the previous day, such as the importance and challenges of communicating the science of rivers, wetlands and ecosystem services to different interest groups, and the potential strategies for doing so.

Taking notes during a plenary discussion session

More food for thought emerging from the discussions

El Centro Nacional Patagónico is located just a short distance from where the first contingent of Welsh emigrants set foot on the Patagonian shore. On a warm and sunny yet breezy day, Hywel and I took advantage of the generous lunch break to walk to the shore, where we tried to imagine the first thoughts of those emigrants as they contemplated their new home. At the end of the day, in the setting sun and enveloping dusk, we also did a quick tour of the various monuments to the Welsh settlers that are dotted along the Puerto Madryn seafront, some of which rightfully acknowledge the role played by the native peoples in helping the fledgling settlements. And thanks to CENPAT’s generosity, we were then treated to a meal in a local seafood restaurant. In setting out for the 1.5 hour drive back to Gaiman, we ran into the inevitable late night police roadblock on the outskirts of town, but luckily our immaculate paperwork and knowledge of the Welsh footballer Gareth Bale smoothed the potentially awkward conversation, and the delay was only minor.

The south end of Puerto Madryn seafront, located near to where the first contingent of Welsh emigrants disembarked 154 years ago


Wednesday 13th March

Reflections on the second day’s activities and a look forward to day 3

Wednesday’s activities again took place at the Trelew campus of UNPSJB. Again, there was a mixed audience of about 70 people but today the room was much cooler thanks to cloud cover and periodic burst of rains. While the coolness was welcome, the rain provided a portent of things to come. This day’s theme was different yet complementary to those on previous days, focusing more explicitly on ecosystem services. Presentations were given by CENPAT and UNPSJB researchers on aspects of ecosystem service delivery and landscape restoration approaches in the lower Chubut River valley, while a presentation by Hywel and myself highlighted how geotourism can tap the often underappreciated cultural ecosystem services.

A view from the back of the room as day 3 gets underway

Just before our presentation, we had been whisked away to a noisy corridor to give an interview to a local TV network about the workshops and its intentions. While the interview went well, it was brief, and plans were made for a more extended interview the next day at the network’s station. After our presentation, breakout group activities and a plenary discussion took place. As with the previous days’ discussions, I found it hard to follow everything that was said: my understanding of rapidly spoken Spanish is just not up to the task. But I had quickly realised that this was not the point anyway. Instead, it mattered more that discussions had been generated amongst a cross section of people who live and work in Patagonia, and who need to be engaged with the issues. And even with a partial understanding, and the translator’s summary of the main points, we got the feeling that the relatively unknown topic of geotourism had created a genuine buzz amongst many of those present, with positive feedback being given to our presentation and several useful contacts for potential future projects being made.

Andrés Malnero gives a colourful presentation


Hywel presenting some of Sioned Llywelyn’s PhD findings: can approaches to geotourism developed in Wales be applied in the Patagonian context?

Wednesday lunchtime and afternoon provided a chance to start fleshing out the details of the numerous possible future collaborative projects, identification of which is a key requirement of the British Council scheme. Luckily, there was no shortage of enthusiasm, more a need for prioritisation and logical sequencing of projects, especially bearing in mind the necessity for additional funding.

A working lunch at the Touring Club.  One side of the table …

… and the other.

Hywel opens his presentation to the Welsh Association of Trelew San David

Wednesday evening involved a presentation by Hywel (in Welsh, with Spanish translation) to the Welsh Association of Trelew San David. A tremendous electrical storm that was breaking in the valley around the time of the presentation had kept a few potential attendees away but added a tinge of excitement to proceedings. The presentation provided lots of scope for discussion among the local Welsh-speaking community, some of whom are descended from the early settlers, particularly as we were able to report a summary of our findings from our previous project undertaken in early 2014.

Heavy rain creates problems in some of Trelew’s bars and restaurants

After the presentation had finished, we heeded reports of a power cut in Gaiman that had resulted from the storm. As such, we stayed in Trelew with some people from the presentation, enjoying food and a drink in a restaurant despite the continuous heavy rain that ensured a steady drip of water through parts of the roof.

We returned to Gaiman late in the evening, finding in the still incessant rain that the electricity was still out in much of the town.

Thursday 14th March

In the morning, still there was no power and the rain continued. We headed into Trelew for a meeting with Gabriel who would take us to the intended interview at the TV station, but a power cut there had meant that this had to be cancelled. This news came too late for our translator who had travelled all the way down from Puerto Madryn, but we made good use of a meeting in a local café with a review of the previous day’s activities and plans for future projects.

Heading into the desert on a very wet day

The rain had raised some uncertainty over whether our initial plans for a trip to stream gauging sites located in the Patagonian desert should go ahead. Heavy rain can make the dirt tracks in the desert tough going or impassable. But with the rain seemingly easing, we decided to go for it. Travelling up the north side of the lower Chubut valley by tarred road, then crossing the irrigated floodplain and river onto the dirt tracks on the south side of the valley, after about an hour we found ourselves passing through increasingly more rugged terrain. Some very heavy bursts of rain continued, but having got this far, we were not going to be deterred.

A flow gauge but with nothing to measure

Our first visit was to a stream gauging station located along one of the numerous normally dry creeks that dissects the desert margins of the valley on its course to the permanently-flowing Chubut River. Since starting my PhD studies in Australia just over 26 ago, I have spent many hours wandering up and down similar creeks – technically known as ephemeral rivers – in various parts of the world, yet had never witnessed any actually flowing. And I’ll admit that I was a little disappointed when even the heavy rain seemed to do no more than simply dampen the sandy bed. Just what sort of rainfall does it take to get these creeks to actually carry flow?

A view across a very wet desert

But as we drove around other parts of the desert, it became obvious that on the usually sun-baked surfaces above the rivers, water was starting to pool or be shed downslope, while smaller creeks were starting to carry flow. We walked across rugged hillsides to larger creeks, many of which were also now starting to flow, and flow more forcefully. We were wet through but hey, ‘merece la pena’ … it was worthwhile. Finally, I would have my own photos and videos of a water-activated desert to use in future presentations. But after a few hours, we were all getting a bit cold, and it was time to head back to town for an evening parilla (barbeque).

A desert pavement, shedding water in the rain just like one constructed of concrete

Walking across the hillside to a creek in flood

A desert creek roaring ever more loudly

A flow gauge, now with something to measure

The desert had other ideas. As we returned to cross the previously dry creek with its gauging station, we found that a raging torrent now blocked our exit. With a depth of around 1 m and an estimated flow speed of about 2 m per second, this was far too dangerous to cross by vehicle, and we had no choice but to wait it out and hope that the water level would drop sufficiently in a couple of hours.

Our route out of the desert is blocked

We made good use of the delayed departure, visiting other flooded creeks to capture more footage. But as the day wore on, the rain continued in bursts, and the water level did not seem to be receding very fast, concern set in. Serious thoughts were being given to spending a night in a nearby house that formed part of a kaolin plant set in the desert, but with just what food provisions I didn’t dare ask. I was more concerned about the almost unthinkable possibilities of not being able to exit the desert even the next day and then missing our flight back to Buenos Aires. “Cuando en el desierto patagónico los arroyos braman” (“When the creeks roar in the Patagonian Desert”). So goes the title of an article written by Gabriel and colleagues. The creeks were roaring for sure, and I was doing some inner roaring of my own. Luckily, just when all seemed lost, at dusk the owner of the kaolin plant took us to the creek to assess the situation. It was still flowing, albeit slightly less deeply and swiftly than a hour or two beforehand. But it was enough to convince the plant owner that it was safe to cross, and without much warning he did just that, barreling through the turbid current and soft sandy bed to the drier, firmer gravel on the far side.

With some trepidation, we followed, and also crossed safely. A slow journey at dusk then ensued along the rest of the dirt road, which now supported significant pools of water. But after dark, we finally reached the relative safety of the tarred road that runs along the more central and northern part of the lower Chubut valley, and we all breathed a collective sigh of relief.

Eventually, we made back to Trelew and the parilla, tired but with a tale that will live long in the memory.

Friday 15th March

The Chubut River in Gaiman with its cargo of desert sediment

After breakfast, we packed and left Gaiman, heading into Trelew for a meeting at the university with Gabriel and others to discuss future project proposals and British Council reporting requirements. The rain was easing but in Gaiman the Chubut River had turned the colour of milky hot chocolate thanks to the sediment-laden runoff from the desert creeks that join the river farther upvalley, while in Trelew, large puddles occupied many of the side roads. Reports were also being received of heavy rain and flooding in Puerto Madryn. While not on the scale of some previous rural and urban flood events that have impacted on this part of eastern Patagonia in recent years, the potential for the severe disruption that can result from rainfall and river flooding was abundantly clear.

A flooded side road in Trelew

A whiteboard full of potential project ideas …

The discussions about future project proposals and reporting requirements were easy. With no shortage of ideas, instead the difficulty was scribbling every idea into the available whiteboard space. We would have plenty to contemplate during our return trip and in the weeks and months to come.

… but which ones to prioritise?


Remainder of Friday 15th, and Saturday 16th to Sunday 17th March

As for the return trip …. one quick stop at a lifesize model of the world’s largest dinosaur (a 42 m long, 12 m tall titanosaur sauropod, located near Trelew airport) before we returned our hire car. One uneventful mid evening flight to Buenos Aires. One night in a very noisy downtown Buenos Aires hotel. One Sunday morning walk around the decaying streets of San Nicolás, Monserrat and San Telmo. As for the very turbulent, cramped flights to Frankfurt and Birmingham, the less said the better. The same goes for the expectedly awful train/replacement bus journey from the Birmingham Airport to a location close to Aberystwyth (note the emphasis on close to, but not actually to, Aberystwyth, thanks to rail engineering works and the seemingly little thought given to those who actually needed to reach the end of the line). But thanks to the generosity of a local friend who arranged to pick us up late at night, both Hywel and I got back to our respective homes just before midnight.


People sometimes question why academics at a Welsh university are doing geographical research in Argentine Patagonia. We typically counter by saying that despite the great distance between the two regions, we share some common history and have enduring cultural ties. But also relevant is that despite considerable differences in average climatic conditions, we also face many common environmental challenges, including dealing with extremes of rainfall, flood and drought, and ensuring wise use of the ecosystem services provided by rivers and wetlands. And to neatly illustrate this point, as we were leaving rain-soaked, partially flooded eastern Patagonia and making our journey back to Wales, we learnt of heavy rain in Bala and many other parts of Wales. According to Natural Resources Wales, Capel Curig, located only about 30 miles by road from Bala, had received more than half a month’s worth of rain (136.6 mm) in 24 hours.

Screen shot of a BBC website highlighting heavy rainfall and flooding in Wales

The Conwy, the Dyfi, the Wye and many other rivers were in flood, with flood warnings issued for several towns (including Bala), while landslides had occurred in some steeper terrain, leading to severe disruption to rail and road transport. Meanwhile in parts of eastern Patagonia, the bad weather had also continued: we later heard that since Friday schools in parts of Puerto Madryn, Trelew and Rawson had been closed and many people had not had potable water in their houses.

Under a warming, more variable climate, the overwhelming scientific consensus is that such weather extremes are likely to be more common in the years ahead, a situation that inevitably will influence the nature and quality of ecosystem service delivery and regularly test community and wider societal resilience. Significant challenges will be faced, to put it mildly. But through schemes that promote knowledge exchange between academics and other interested parties, such as those funded by the British Council, we are more likely to be able to identify strategies and solutions that will help us rise to such challenges.

Wetlands in drylands: how good is the service?

Monday 17th November 2014

The Vaal River, South Africa: an important ecosystem service provider in a dryland setting

The Vaal River, South Africa: an important ecosystem service provider in a dryland setting

Around 1800, the world’s population reached one billion for the first time.  Just over 200 years later, this figure exceeds seven billion … and is still rising.  With such explosive growth, human activities such as agriculture, mining, dam building, manufacturing and urbanization have had profound, long-lasting, negative impacts on the natural environment.  Decades-old worries over air pollution, soil contamination, and the hole in the ozone layer almost seem quaint by comparison with ever-more-urgent concerns over issues such as groundwater depletion, species extinctions, and a warming planet.  At the same time, there is growing recognition that human wellbeing is partially dependent on a healthy natural environment.  Wellbeing includes the obvious physical aspects, but also more subtle mental aspects.  As an example, the term ‘nature deficit disorder’ has arisen amid growing concerns that humans, especially children, are spending less time outdoors, resulting in a wide range of behavioural problems (see

Against this backdrop, the term ‘ecosystem services’ has entered the scientific domain, and is defined as the benefits that people obtain from ecosystems.  The Millennium Ecosystem Assessment (MEA) – a four-year (2001-2005) collaboration involving more than 1360 experts worldwide – provided a state-of-the-art appraisal of the condition of the world’s ecosystem services, and assessed the consequences of ecosystem change for human wellbeing (  The MEA classified ecosystem services into four main types: provisioning, regulating, supporting, and cultural.  It also noted that although the human species is buffered against environmental changes by culture and technology, it remains fundamentally dependent on the flow of ecosystem services.

Diagram from the Millennium Ecosystem Assessment illustrating how many aspects of human wellbeing are dependent on provisioning, regulating, cultural and supporting ecosystem services

Diagram from the Millennium Ecosystem Assessment illustrating how many aspects of human wellbeing are dependent on provisioning, regulating, cultural and supporting ecosystem services

Alongside coverage of various terrestrial and marine ecosystems, the world’s wetlands (defined broadly by the MEA) received special consideration.  The marshes, fens, swamps, peatlands, shallow water bodies and rivers in tropical, temperate and arctic regions were noted as delivering a wide range of ecosystem services, such as fish and fibre, water supply and purification, flood and climate regulation, coastal protection, and recreational and tourism opportunities.  But within the voluminous MEA volumes (the specific ‘Wetlands and Water’ synthesis volume alone runs to 68 printed pages), just how comprehensive was coverage of wetlands in drylands?  Drylands are the world’s extensive hyperarid, arid, semiarid and dry subhumid regions, and so while ‘wetlands in drylands’ sounds like a contradiction in terms, wetlands in fact can form and persist wherever a positive water balance exists for at least part of the year.  In many drylands, this most commonly occurs where river inflows combine with other factors that serve to impede drainage, including tectonic faulting, swelling soils, and ponding by wind-blown sediments.  Many individual wetlands in drylands may be relatively small compared to some tropical, temperate and arctic wetlands, but collectively they can form across a diverse range of dryland settings.  More importantly, by dint of their presence in otherwise largely dry environments, the MEA recognised that wetlands in drylands may be disproportionately important in terms of biodiversity and other ecosystem services.

Critical reading of the MEA volumes, however, reveals that hard facts about wetlands in drylands are in short supply, and many assumptions remain untested.  For instance, given that many wetlands in drylands desiccate on seasonal or longer bases, how similar are they to their more-or-less permanently-saturated tropical, temperate and arctic cousins?  Do wetlands in drylands necessarily serve to improve water quality for downstream users, or might there be situations where water quality actually decreases downstream of wetlands (e.g. where dry season grazing increases fecal contamination of the desiccating water bodies)?  Are wetlands in drylands really stores of carbon and therefore important contributors to global climate regulation (e.g. through incorporation of atmospheric carbon dioxide into vegetation and ultimately organic-rich soils), or might dry season fires simply burn off the vegetation and organics, thus returning carbon dioxide straight back to the atmosphere?  And to what extent are the provisioning, regulating, supporting and cultural services actually compatible, or might there be potential for conflict, especially where wetlands are the subject of competing human interests?

To examine these and other related questions, colleagues and I recently convened a three-day workshop entitled “Wetlands in Drylands: Past, Present and Future Trends in Ecosystem Service Provision” near Parys, Free State Province, South Africa.  The workshop was funded as part of the Royal Society’s UK-South Africa Scientific Seminars Scheme.  The overarching objective was the establishment of a network of researchers to advance the science of wetlands in drylands, and to translate scientific findings into forms that can be assimilated by those charged with wetland conservation, rehabilitation and management.

The scheme paid for four UK and twelve South Africa participants to convene at the magnificent Stonehenge in Africa conference venue (, located 6-7 km west of Parys.  Situated close to the epicentre of the World Heritage-listed Vredefort Dome – arguably the world’s oldest (2.02 billion years) and largest (greater than 300 km wide) meteorite impact crater – and with a lawn that slopes down to the north bank of the Vaal River, the venue was never going to disappoint.  While the visual impact of the surrounding impact crater is somewhat muted on account of its vast age and size (one really needs an aerial perspective and geomorphologist’s eye to fully appreciate its grandeur), the permanently-flowing pools and rapids, and the green, tree-lined islands of the Vaal present a magnificent sight, especially as they contrast so starkly with the surrounding, usually much drier, browner terrain.  In the MEA’s terms, surely the Vaal must rank as one of South Africa’s most important riverine wetlands, providing good service for locals and visitors alike?

Bedrock rapids and boulders along the Vaal River at Stonehenge

Bedrock rapids and boulders along the Vaal River at Stonehenge

The journey to the conference venue was trouble free.  During preparations for landing at OR Tambo airport, I caught glimpses of some of the wetlands around Johannesburg’s sprawling peri-urban fringe, many of which purify poor quality water emanating from malfunctioning sewerage systems and gold mine dumps.  The plane had landed on time, and we breezed through customs.  After meeting some other workshop participants, we piled into a minibus for the two hour-drive drive southwest to Stonehenge.  As we trundled ever nearer, there was an African welcome typical of November: an ever-darkening sky, followed by spectacular lightning bolts and a torrential downpour.  Wet season thunderstorms were arriving in a land parched by an eight month-long dry season … over the coming weeks, river flows would increase, wetland water bodies would fill, and green shoots would lighten dampened soil.  In this instance, the downpour didn’t last longer than about 10 minutes, but the dark sky, lightning and thunder hung around, providing a constant threat of rain.

And over the next three days, torrential rain did return several times, often accompanied by lightning and thunder.  We didn’t see much sun, which at this time of year normally makes a welcome visit between thunderstorms.  These meteorological conditions lead to some sleep-disturbed nights and one short-lived power outage, while leaking roofs caused inconvenience in a few bedrooms and communal areas.  But these conditions didn’t affect the torrent of ideas emanating from the workshop activities, which included short presentations, small group discussions and round table debates.

Attentive participants during one of the session talks

Attentive participants during one of the session talks

Following some introductory sessions, the first two days considered wetlands in drylands and their ecosystem services from the perspective of the past, present and future.  To what extent did wetlands in the past serve as key hominin habitats and migration routes from Africa to other parts of the world?  How can we best translate wetland science into current wetland management policy?  Which wetland ecosystem services are most threatened by projected future climate changes?

At the end of day two, I arranged for the participants to visit two local contacts of mine, whose house is located along the margins of the Vaal just a few kilometers upriver of Stonehenge.  To complement a generous provision of wine and snacks, our hosts took us for a walk on one of the numerous river islands, and we chatted about the Vaal and other important South African rivers.  A lifetime of kayaking South Africa’s rivers, coupled with more than 10 years living by the Vaal, has sharpened their awareness of the quality of river and wetland ecosystem service provision, even if this is not a term that they would use.  And in most instances, the service is declining as a result of human activities, including active mismanagement.  In the case of the Vaal, as with many other river and wetland ecosystems, factors such as flow regulation, raw sewage disposal, and invasive vegetation have dealt severe body blows, precluding optimal service provision.

Worse still are some of the threats facing the Vaal’s larger sibling, the Orange River.  Having long researched the landscapes of the lower Orange valley, I had already become aware of the proposed run-of-the-river hydropower developments for some of the most scenic, pristine and inaccessible reaches, including the supposedly protected, much visited Augrabies Falls and the downstream, lesser known Ritchie (Oranje/!Gariep) Falls (  If a green light is given, the developments will divert water from some of the Orange’s bedrock channels, waterfalls and gorges so that it can be run through turbines.  Relatively small amounts of electricity will be generated, much of which is destined for consumption by Namibia.  The threats to river ecology, geoheritage, and the sense of wilderness in these reaches is being given lip service – at best – by the developers and their consultants.  Potentially, this represents yet one more body blow to an already weakened ecosystem.

The final day considered how new scientific techniques can best be employed in the study of wetlands in drylands and their ecosystem services, and concluded with a discussion of the way forward for our nascent research network.  Plans are for state-of-the-art publications, an online presence to support network activities, and a future workshop.  Much more needs to be done to promote research into wetlands in drylands and their ecosystem services, so that the types of questions posed above can be answered.

A busy agenda and a long list of ideas for post-meeting activities

A busy agenda and a long list of ideas for post-meeting activities

But during preparation for the final session – partly done during the middle of night as I lay awake listening to yet another thunderstorm – I had already found an answer to at least one of those questions.  A definitive ‘no’.  The various ecosystem services provided by rivers and wetlands in drylands are not necessarily compatible.  It struck me that the provisioning, regulating and supporting services often take centre stage, effectively sidelining the cultural services.  In the case of the lower Orange River, certain interest groups are listing hydropower generation among the provisioning services, and are prioritising this service to the virtual exclusion of all others, particularly the cultural services that include aesthetic, spiritual, educational and recreational opportunities.  The installations and infrastructure associated with hydropower developments will undoubtedly detract from all these cultural services, so one has to question this prioritisation.  Cultural services may be more nebulous than electricity generation, and less easy to monetise than megawatts, but in a world where a sense of wilderness is rapidly disappearing and ‘nature deficit disorder’ is now a recognized condition, what are the hidden costs?