The Horn of Africa has had years of drought, yet groundwater supplies are increasing – why?

 

Harvepino / shutterstock

The Horn of Africa – which includes Somalia, Ethiopia, Kenya and some surrounding countries – has been hit by increasingly frequent and devastating droughts. Despite this, it seems the region has an increasing amount of groundwater. And this water could help support drought-stricken rural communities.

That’s the key finding from our new research, in which we discovered that while overall rainfall is decreasing, an increase in “high-intensity” rainfall has led to more water being stored deep underground. It’s a paradoxical finding, yet one that may help one of the world’s most vulnerable regions adapt to climate change.

In the Horn of Africa, rural communities live in a constant state of water scarcity punctuated by frequent periods of food insecurity. People there rely on the “long rains” between March and May and the “short rains” between October and December to support their lives and livelihoods.

As we write this, the region’s drylands are experiencing a fifth consecutive season of below-average rainfall. This has left 50 million people in acute food insecurity. The droughts have caused water shortages, livestock deaths, crop failures, conflict and even mental health challenges.

The drought is so severe that it is even affecting zebras, giraffes and other wildlife, as all surface waters are drying up and edible vegetation is becoming scarce. Worryingly, a sixth failed rainy season has already been predicted for March to May 2023.

Long rains down, short rains up

In a new paper we investigated changes in seasonal rainfall in the Horn of Africa over the past 30 years. We found the total rainfall within the “long rains” season is declining, perhaps related to the warming of a particular part of the Pacific Ocean. However, rainfall is increasing in the “short rains”. That’s largely due to a climate phenomenon known as the Indian Ocean Dipole, when a warmer-than-usual Indian Ocean produces higher rainfall in east Africa, similar to El Niño in the Pacific.

We then investigated what these rainfall trends mean for water stored below ground. Has it decreased in line with declining “long rains”, or risen due to the increasing “short rains”?

Map of East Africa
The Horn of Africa borders the Red Sea, the Gulf of Aden and the Indian Ocean.
Peter Hermes Furian / shutterstock

To do this we made use of a pair of satellites which orbit repeatedly and detect small changes in the Earth’s gravitational field that can be interpreted as changes in the mass of water storage. If there’s a significant increase in water storage underground, then the satellite will record a stronger gravity field at that location compared to the previous measurement, and vice versa. From this, the mass of water added or lost in that location can be determined.

Using these satellite-derived estimates, we found that water storage has been increasing in recent decades. The increase correlates with the increasing “short rains”, and has happened despite the “long rains” getting drier.

Given that the long rains deliver more seasonal rain than the short rains, we wanted to understand the paradoxical finding that underground water is increasing. A clue is given by examining how rainfall is converted into groundwater in drylands.

When rain is light and drizzly, much of the water that reaches the ground dampens the soil surface and soon evaporates back into the warm, dry atmosphere. To become groundwater, rainfall instead needs to be intense enough so that water will quickly infiltrate deep into the soil. This mostly happens when lots of rain falls at once and causes dry riverbeds to fill with water which can then leak into underground aquifers.

People stand in river, rainy sky.
Heavy rains fill a dry river bed in the Somali region of Ethiopia.
Stanley Dullea / shutterstock

These most intense rainfall events are increasing in the “short rains”, in line with the overall increase in total rain in that season. And despite a decrease in overall rainfall in the “long rains”, intense rainfall has remained consistently high over time. This means that both rainy seasons have enough intense rainfall to increase the amount of water stored underground.

Finally, we demonstrated that the increasing water storage in this region is not connected to any rise in soil moisture near the surface. It therefore represents “banked” water that resides deep below ground and likely contributes to a growing regional groundwater aquifer in this region.

Groundwater can help people adapt to climate change

While early warning networks and humanitarian organisations focus on the urgent impacts of drought, our new research points to a silver lining that may support long-term climate adaptation. Those rising groundwater supplies we have identified may potentially be exploited to support people in rural areas whose food and water are increasingly insecure.

But there are some caveats. First, we have not assessed the depth of the available groundwater across the region, but we suggest that the water table is shallow enough to be affected by seasonal rainfall. This means it may also be shallow enough to support new bore holes to extract it. Second, we do not know anything about the quality of the stored groundwater and whether it can be deemed suitable for drinking. Finally, we do not know exactly what will happen if the most extreme droughts of the past few seasons continue and both long and short rains fail, causing intense rainfall to decrease too.

Nevertheless, our findings point to the need for extensive groundwater surveys across the Horn of Africa drylands to ascertain whether this increasing water resource may be viable enough to offset the devastating droughts. Groundwater could potentially irrigate fields and provide drinking water for humans and livestock, as part of a strategy to help this vulnerable region adapt to the effects of climate change.The Conversation

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This blog was written by Cabot Institute for the Environment member Katerina Michaelides, Associate Professor, School of Geographical Sciences, University of BristolMichael Singer, Professor in Physical Geography (Hydrology and Geomorphology), Cardiff University; and Markus Adloff, PostDoctoral Researcher, Earth System Modelling, Université de BerneThis article is republished from The Conversation under a Creative Commons license. Read the original article.

#CabotNext10 Spotlight on Water

 

Dr Katerina Michaelides

In conversation with Dr Katerina Michaelides, co-theme lead at the Cabot Institute

Why did you choose to become a theme leader at Cabot Institute?

I was particularly attracted to this role because I am strongly committed to increasing the visibility of the great water-related work going on in the University, and because I feel strongly about developing the water research community within Bristol and further afield. Over the years since its creation, Cabot Institute has been instrumental in developing my connections with others within the University, in fostering new collaborations and in encouraging new and creative avenues of research. In that same spirit, I relished the opportunity to perform a similar role within the Cabot Water theme and give back to the community by helping to foster collaborations, contacts, and new avenues of research. I believe in the Cabot mission and ethos and felt that I can help strengthen the Water theme in this more formal role.

In your opinion, what is one of the biggest global challenges associated with your theme? (Feel free to name others if there is more than one)

One of the biggest impacts of climate change is on the water cycle. In fact, climate change can be thought of as synonymous with changes in the water cycle with far reaching implications for lives and livelihoods. Think catastrophic storms, droughts, floods, declining water quality. Water is such a fundamental part of life that many in the global north take for granted. So if I was to say one biggest challenge, I would say: addressing global water scarcity and food insecurity challenges under climate change and anthropogenic pressures. There are of course, many other challenges….

Across the portfolio of projects in your theme, what type of institutions are you working with? (For example, governments, NGO’s)

Our theme members work with a huge range of non-academic institutions – from insurance companies, charities, climate services providers, NGOs, local businesses among others.

What disciplines are currently represented within your theme?

We have a broad set of disciplines within the Water theme. These range from water and sanitation, climate impacts on water balance, flood risk and hazard modelling, flooding and infrastructure resilience, freshwater biogeochemistry (water quality), hydrometeorology, dryland hydrology, tropical hydrology, hydrological modelling, forecasting floods and droughts, water, and humanities. And much more!

In your opinion, why is it important to highlight interdisciplinary research both in general and here at Bristol?

Global challenges related to water and climate impacts are inherently multi- and interdisciplinary in their nature. It starts from understanding how climate is changing, to how these changes impact the water balance on the ground hydrology) and may lead to destructive floods or devastating droughts through their effect on agriculture and drinking water. Ultimately, because water intersects society on so many different levels (from natural disasters, to agriculture, to water resources, to droughts) research needs to be interdisciplinary and consider both environmental and social aspects of the problem.

Are there any projects which are currently underway in your theme which are interdisciplinary that you believe should be highlighted in this campaign?

There are lots of interdisciplinary projects across the Water theme. Personally, our research focusses on water scarcity, as highlighted by these two projects below:

Drought Resilience in East African dryland Regions (DRIER) – This is a collaboration between hydrologists, climatologists, social scientists, livelihoods experts, climate adaptation experts. Awarded a Royal Society Grant of £500K for 2020-2023, with Bristol leading and colleagues from Cardiff, UEA, University of Nairobi, and Addis Ababa University. DRIER has been selected as case study for the Royal Society Challenge-Led grant scheme and by BEIS for the GCRF.

Mobile App Development for Drought Adaptation in Drylands (MADDAD) – This interdisciplinary project between hydrologists and computer scientists, funded by a GCRF Translational Award (2019-2021) is developing a mobile phone app to deliver water status forecasts to remote communities in Kenyan drylands. Under climate change droughts are set to become more intense and frequent and there is a pressing need for relevant, timely, and practical information about water resources, particularly with a view to climate change adaptation. However, rural agro-pastoral populations are sparse and distant from decision-making centres making it hugely challenging to disseminate useable information in a timely manner. The provision of a mobile phone app has the potential to transform decision-making and drought adaptation for a large number of people in remote, rural dryland regions of East Africa that currently do not have access to useable and relevant information about the short- and long-term changes in water scarcity in their location.

Down2Earth – Translation of climate information into multilevel decision support for social adaptation, policy development, and resilience to water scarcity in the Horn of Africa Drylands. Awarded an EU H2020 Grant of €6.7M for 2020-2024, with Cardiff University as the lead Institution and ~€1M to University of Bristol. In total, 15 Institutions across UK, EU, East Africa, are involved, including many non-academic actors. This project is completely multi-disciplinary in nature.

For more information, visit Water.

World Water Day 2021: What does water mean to the Cabot community?

 

It’s World Water Day (22 March) and we have joined the global public campaign on the theme for 2021 of valuing water. The campaign is designed to generate a worldwide conversation about how different people in different contexts value water for all its uses.
So we asked researchers, students and staff at the Cabot Institute for the Environment, what does water mean to you? Whether it is something learnt through research, personal experiences or simply what you think when you think of water, we asked our community for stories, thoughts, and feelings about water!
All responses including ours and many others across the world will be compiled by UN-Water to create a comprehensive understanding of how water is valued and to help safeguard this resource in a way that will benefit us all.
Cabot Institute for the Environment researchers and students are doing lots of wonderful and important work to deliver the evidence base and solutions to protect water (find out more). Here is what some of them shared with us for World Water Day #Water2me.

What does water mean to you?

“Water is the most special substance on Earth. Everyone has a relationship with it. It is ubiquitous yet still enigmatic. As a hydrologist I have been working for years to better understand where it goes after it rains. As a person who grew up in semi-arid Cyprus, I know that water scarcity can shape a culture as much as it shapes the landscape. As a person who has been living in the UK, I know that too much water can also shape a culture. Too little or too much – water is both a life giver and a life taker. It is everywhere, nowhere, hidden, precious, ever changing, elusive, wondrous, yet taken for granted.   Dr Katerina Michaelides, Co-lead of Cabot Institute for the Environment water theme 

 

“Liquid water can take any shape of its recipient. As water vapor, it becomes invisible and travels into the air… but it is still there. As ice and it can sometimes provide a hard surface. Water reminds me of adaptation and opportunities. We face a global challenge in ensuring water to all living beings on Earth, but the nature of water tells me that we must adapt to any changes coming in future years and turn challenges into opportunities to develop more sustainable and earth-friendly measures to tackle our societal needs.” – Dr Rafael Rosolem, Co-lead of Cabot Institute for the Environment water theme 

 

 

“Water is the essence of life and its tiny moving molecules connect almost everything on Earth – bodies of water in rivers, glaciers, oceans, atmospheres are connected to our bodies as humans. What happens in one body trickles down and impacts others, so we have to be careful with how we manage this vast cycle of water, and of life.” – Professor Jemma Wadham, Director of Cabot Institute for the Environment 

 

“When you grow up in a country, where 2/3 is a desert with 1 hour of water supply per 48 hours (mainly at 2am!), water is more precious than oil and sometimes gold.” – Dr Hind Saidani-Scott, Cabot Institute for the Environment researcher 
“Simply put, water means health, safety, and life 💧 Without clean water, access to this becomes limited, whereas with it – we can thrive 🌍” – Olivia Reddy, University of Bristol PhD candidate and member of Cabot Institute for the Environment ‘Cabot Communicators’ group.

 

As a kid to me water meant fun, it sparked feelings of joy and excitement for swimming in the ocean and having a good time. While water remained a magical thing to me, as I grew older, I began to consider its role as a global resource, its precarity, need for protection and how lucky I was to have access to it. Now as I undertake my research at Cabot, I am learning more about the spirituality and sacrality of water amongst indigenous cultures, not only as a “resource” but at as point for worship, ceremony, and community and something to learn from. Today I understand water as part of us as well as our world” – Lois Barton, post-graduate researcher, Global Environmental Challenges, Cabot Institute for the Environment       

 

 
“The first thing I would have said when asked to think about water two years ago is a refreshing glassful from the tap. But watching the film Cowspiracy and following this up with my own research into animal agriculture has made me look at water differently. Now, I think of water in terms of cows. 2,500 gallons of water are needed to produce one pound of beef. Animal agriculture is responsible for up to 33% of freshwater usage globally! For me, a new understanding of water and water-use was a key factor in prompting the decision to change to a plant-based diet and advocate that others do the same for the good of the planet and the people who do not have water on tap like I do every day. – Lucy Morris, post-graduate researcher, Global Environmental Challenges, Cabot Institute for the Environment

Hidden Water: Valuing water we cannot see 

Cabot Institute for the Environment is also hosting a public event for World Water Day (17:15 GMT, 22 March 2021) which is bringing together two leading researchers to discuss the value of ‘hidden water’ resources: groundwater and glaciers. 
 
Dr Debra Perrone, University of California, will discuss her research which revealed millions of groundwater wells and strategies to protect them. Professor Jemma Wadham, Cabot Institute for the Environment, will discuss the impacts of glacier retreat in the Peruvian Andes and solutions to adapt to these changes. Chaired by Cabot Institute for the Environment water experts, Dr Katerina Michaelides and Dr Rafael Rosolem. More information here

Join the discussion

What does water mean to you? Tag @cabotinstitute and #WorldWater #Water2me on Twitter to let us know.

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This blog is written by Adele Hulin, Cabot Institute Coordinator at the University of Bristol, and Lois Barton, Cabot Institute for the Environment MScR student and temporary communications assistant at the Institute.
Adele Hulin
Adele Hulin

Olive oil production in Morocco: so many questions

No standard salad would be complete without olive oil. Our friends the lettuce, tomato and cucumber now come automatically accompanied by the vinegar and the oil, the oil and the vinegar. Perhaps in a bottle, perhaps in a sachet, perhaps in some kind of over complicated vinaigrette processed by a supermarket near you, along with lots of salt and some corn syrup, a 21st century salad in the Western world would be naked without an olive dressing.

This weekend, after an intensive academic seminar in Morocco[1], we studious seminar attendees were rewarded with a field trip. So I was taken out to visit three agricultural holdings in action. They all grew olives, but apart from that, had little in common. These three: large, medium and small producers in turn gave us a hugely insightful opportunity to witness agricultural change in action. Since the turn of the millennium the large site, on previously colonial, then state-held land had been an apple orchard and had now turned to olive oil. The medium one had been focused on cattle, making use of previous common land, that was now enclosed land, and was now diversifying with oil, watermelons, and more. The small producer produced a full range of things including olives for their own oil and most recently had established a side income in both fish and honey production.

Firstly, we learnt how to make money. Morocco’s heavily financed agricultural development programme, Plan Maroc Vert, which aims to intensify the agricultural system into a new-age competitive beacon of the modern food system, offers attractive incentives to spruce up agriculture in the country with new machines. All you need is to write a proposal (a report), have money to invest (from bank credit perhaps) and an impressive part of your money will be returned to you in state subsidies within two years.

So, for example, all three of the small, medium and large producers we visited, had benefited from a 100% state subsidy for irrigation of their crops. In the case of the ‘super-intensive’ large producer this meant state funding for the irrigation of 65,780[2] olive trees from groundwater on a rapidly declining water table. Some of the more landscape-savvy of the seminar group reminded us that olive trees had been grown in the region for centuries precisely because they did not need this kind of constant watering but could grow deep roots and access scarce water themselves. This, however, is not of interest to the ‘super-intensive’ producer. This producer is simply interested in the logic of economic growth, which in this case says: plant the trees closer, and add the chemical nutrients to the water while you’re at it. And so, these 65,780 trees are watered with the addition of nitrogen, phosphorus, potassium and ammonium, yet no studies are evident of what all these substances may be doing to the groundwater. By any other logic this would be a big concern, nitrogen pollution, particularly. Nitrogen pollution of water supplies, or more simply, of the nitrogen cycle, is one of the only planetary ecosystem boundaries that we have already crossed as a human race. This was not relevant in the lesson of how to make money.

Yet, I work with people, so where were they in the Moroccan olive grove? Well, it seems they have been replaced by a machine in this super-intensive oil production. The company, with links to power as far up as it goes, has invested in a machine that drives over the trees like a bridge. It shakes their branches and collects their olives.  So much for an investment in rural employment.

Some new olive trees defy the machine but are pretty un-reliable as employers too. These trees that the machine can’t manage provide jobs for only a very precarious seasonal and short-term workforce. I was told that 100 people would be employed for a space of around 200 hectares, and these jobs would last 2-3 months. The company assured us though that these workers would get both contracts and, in order to have those contracts, bank accounts. Thank goodness the banks aren’t losing out.

I should be kinder in tone about the small and medium sized farmers that we visited. Not only did their olive oil taste a lot richer, but they invited us to tea, and allowed us to share their experience of oil production more closely.  They humoured our partial language skills and our many, many questions. This was the second major thing we learnt on the trip – we were a team. We were a slightly chaotic, and erratic team, but really quite effective. A little like slugs on a cabbage, we chewed up every bit of information every which way.

Releasing a group of 13 researchers at a family farm, was a bit like inviting children to a playground, or providing clowns with an audience. Each of us found something to play with, interact with, reflect upon and smile. Some of us looked at the trees or identified the plant specimens. Others wrote notes, or took pictures, or carried out semi-formal interviews with whichever family member we felt most comfortable with. Others played with material toys, climbing ladders, smelling fruit or knocking on enormous oil containers to discover them empty. As we found the olive branches, force-fed powder food through irrigated pipes, or in the smaller farm providing shade for some resident chickens, this seminar group grew together, discovering the knowledge of the peasant farmer.  This experience was far richer and engaging than any power point presentation or report.

More images can be found on the original blog.

References

[1] “Workshop on Agricultural Labour and Rural Landscapes in the Arab World” Organised by the Thimar collective and supported by the École Nationale d’Agriculture de Meknès, the Leverhulme Trust and the London School of Economics.

[2] Calculated based on 286 plants/hectare in a cultivated area of 230 hectares, this was the details of the holding advertised by the company.

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This blog is written by Lydia Medland, a PhD student at the University of Bristol’s School of Sociology, Politics and International Studies who is looking at the role of seasonal workers in global food production, specifically in Morocco and Spain.  This blog has been reposted with kind permission from her Eating Research blog.  View the original blog post.

Lydia Medland

Read Lydia’s other blog: Watermelon work