Groundwater and climate change revisited: informing adaptation in a warming world

by Prof. Richard Taylor, UCL in The Springer Nature Sustainability Community

Recent research has identified the natural resilience of groundwater to climate change and our tendency to deplete this invaluable resource. It’s time we understood, valued, and governed groundwater as the vital adaptation to climate change that it is.

Continue reading Groundwater and climate change revisited: informing adaptation in a warming world

Groundwater – a hidden resource that has always evaded UN climate talks

By Isaiah Esipisu

A new study that was recently published in the Nature scientific journal shows that groundwater is one of the most climate resilient natural resources especially for the African continent. This is contrary to the earlier understanding by the Intergovernmental Panel on Climate Change (IPCC)’s Fifth Assessment Report , that groundwater was susceptible to climate change in dryland areas.

Though it has not been a subject for major discussions at the 2019 UN Conference of Parties (COP25) on climate change in Madrid, experts believe that groundwater will be at the centre of climate adaptation particularly for African countries.

Richard Taylor, a Professor of Hydrogeology from University College London (UCL) and one of the lead researchers of the Nature study explained why groundwater should be a focal point for climate discussions.

IE: How important is groundwater to climate change adaptation especially in Africa?

RT: Groundwater plays a fundamental role in enabling communities in Africa to adapt to climate change. As our world warms, rainfall becomes less frequent but more intensive resulting in longer droughts and worsening floods – changes that occur most strongly in the tropics.

Adapting to this greater variability in water resources relies on the ability to draw water from stores such as groundwater or to store water in dams for example.

Groundwater, which comprises 99 percent of the Earth’s liquid water, amounts to more than 100 times that of annual river discharge in Africa.

For cities in Africa that have recently experienced severe droughts such as Cape Town and Dar es Salaam, groundwater has played a critical role in enabling residents in those cities to adapt to water scarcity.

Less frequent rainfalls also reduce crop yields. Increasing cropland irrigation is a critical strategy to improve food security in Africa under climate change. As smallholder farmers account for the vast majority of food production in Sub-Saharan Africa, distributed groundwater supplies are often the most cost-effective and sustainable sources of water for irrigation.

IE: How resilient or vulnerable is groundwater to climate change?

RT: Groundwater resources are generally resilient to climate change. Recent evidence from a pan-African study shows that replenishment of groundwater occurs preferentially from heavy rainfalls so that changes in rainfall brought about by climate change favour groundwater replenishment. Alas, these same changes in rainfall reduce soil moisture and lead to greater and more frequent flood events.

IE: Why do you think this subject has not been able to attract the attention of climate change negotiators for the past 25 years of negotiation?

That is a good question. Groundwater is often called the hidden or invisible resource as it lies unseen beneath our feet. Limited understanding of groundwater by both policy makers and engineers means that it is often considered mysterious or unknowable.

The impact of climate change on groundwater resources has been largely ignored by the climate change community until last year when it was captured in the IPCC Fifth Assessment Report.

This is surprising in light of the critical role groundwater plays in sustaining rivers, lakes and other aquatic ecosystems during low or absent rainfall.

IE: What do you think should be done to bring the groundwater subject to the helm of climate negotiations?

RT: There is need for raising awareness of the critical role of groundwater to improving the resilience of water and food systems in Africa in relation to climate change.

It is in that regard that scientists from different parts of the world are issuing a Call to Action this week, through a statement published in the Nature journal, which argue that we are not doing enough to protect and manage global groundwater resources, which will have long-term effects on the planet’s drinking water, food production, and adaptation to a rapidly changing climate.

This statement focuses on the global role of groundwater in relation to the 2030 Agenda for Sustainable Development, the Paris Agreement on Climate Change, the Framework for Action on Groundwater Governance, and the Sendai Framework for Disaster Risk Reduction.

It builds on previous important declarations and statements, including the Valencia declaration on Intensive Groundwater Use (2002), the Kampala statement on Groundwater and Climate in Africa (2008), ISMAR9 call to Action on Sustainable Groundwater Management Policy Directives (2016).

This call has so far been endorsed by over 700 scientists and practitioners in over 80 countries and is timed to coincide with the United Nations (UN) Climate Change Conference in Madrid (COP 25) and the beginning of the Decade of Action on the UN Agenda 2030.

IE: What kind of policies should African governments put in place in order to ensure sustainable use of groundwater?

RT: African governments could do two things. One, they could increase investment in understanding their groundwater resources through the training of staff and the monitoring and evaluation of their groundwater resources.

Two, they could integrate groundwater into its evaluation and governance of water resources more holistically that is currently dominated by concern for surface waters.

In light of the central importance of groundwater to adaptation to climate change, African governments could use support under the Green Climate Fund to finance the implications of these policy recommendations.

Photo: Richard Taylor, UCL

The climate is changing – we need groundwater more than ever

UPGro Ambassador, Dr Callist Tindimugaya, attended last month’s COP meeting in Madrid – the United Nations global negotiation meeting to try an agree ways forward to tackle climate change.

He was attending as part of the Government of Uganda delegation to bring forward opportunities and challenges – in particular the key role of groundwater as a resource that can help buffer against some of the effects of shifting rainfall patterns across Eastern Africa.

In this interview with Isaiah Esipisu, he explains why African groundwater needs to be on the lips of the climate negotiators.

Trickle-down effect: why groundwater recharge processes matter for climate resilience

by Sean Furey (Skat/UPGro Knowledge Broker) in GeoDrilling International

Drilling for water is only useful if there is good water to be had now and into the future. Since 2013, researchers in the UK-funded programme Unlocking the Potential of Groundwater for the Poor, have been working all over Africa to understand better the continent’s aquifers and how their hidden wealth can be used to benefit everyone. Now after years of patient work, exciting results and resources are emerging.

One is that the Africa Groundwater Atlas, curated by the British Geological Survey now has downloadable GIS maps for 38 countries. They are quite large scale, so not detailed enough for individual borehole siting, but a good starting point for identifying where major aquifers are. This supports the wealth of other useful information, in English and French, on the soils, climate and groundwater use in all 52 of Africa’s countries.

Continue reading Trickle-down effect: why groundwater recharge processes matter for climate resilience

Importance of groundwater stressed at climate conference

by Isaiah Esipisu via PAMACC

ADDIS ABABA, Ethiopia (PAMACC News) – Delegates at the Africa Climate Risks Conference have been informed that groundwater is more resilient to extreme climatic conditions especially in arid and semi arid areas, contrary to earlier beliefs – that the resource was vulnerable to the changing climatic conditions.

“Through a project known as Groundwater Futures in Africa, we analysed the relationship between climate change and variability and groundwater in 14 sites in Africa,” Martin Todd, a Professor of Climate Change at the University of Sussex, Department of Geography.

“What we found is that in arid regions, there was episodic recharge, which occur mainly as a result of intense storms that happen every few years, and sometimes even in years of low total precipitation,” said

This, according to the scientist, it means that climate plays a dominant role in controlling the process by which groundwater is restocked.

Generally, it means that extreme periodic flooding is what recharges aquifers in such arid and semi arid areas, providing a lifeline and livelihoods for people who depend on groundwater in such areas.

The findings, which have since been published in the Nature scientific journal contradicts the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), which states that ‘climate change over the twenty-first century is projected to reduce renewable surface water and groundwater resources significantly in most dry subtropical regions, intensifying competition for water among sectors.’

According to Prof Todd, groundwater is generally overlooked in terms of climate impact, and it is also an overlooked resource in Africa and underutilised compared to other continents.

“With the rapid population growth and quest for development, there is going to be huge demand on water resources, and therefore we expect that groundwater is a resource that will be heavily developed in the future because climate change and variability is going to place increasing threat to surface water,” he said.

The new findings from the study, which was supported by the United Kingdom research councils (Natural Environment Research Council, Economic and Social Research Council and the Engineering and Physical Sciences Research Council), the Department for International Development (DFID) and The Royal Society also highlight the need for improvements in models of climate and hydrology.

The report indicates that climate models that can better predict the variability and intensity of precipitation events at the local scale, as well as the large scale, would allow hydrological models to better represent replenishment processes.

Given a fact that extreme floods can be predicted up to nine months in advance, the researchers say that there is a possibility of designing schemes to enhance groundwater recharge by capturing a portion of flood discharges via a process known as Managed Aquifer Recharge.

According to the British Geological survey, successful and sustainable development of groundwater resources in Africa is critical for future safe water supplies, economic growth and food security in the continent.

The findings have come at a time several cities across the continent are beginning to exploit the groundwater, which has for long been considered a hidden resource.

So far, groundwater plays a central role in sustaining water supplies and livelihoods in sub-Saharan Africa due to its widespread availability, generally high quality, and intrinsic ability to buffer episodes of drought and increasing climate variability.

Given the drying rivers and streams, and unpredictable rainfall patterns, groundwater is likely going to be a golden resource in Africa’s rural communities both for domestic consumption and irrigation.

Photo: Isaiah Esipisu

 

OPINION:- It’s time to look underground for climate resilience in sub-Saharan Africa

Karen G. Villholth is a Principal Researcher with the International Water Management Institute (IWMI) and CGIAR Research Program on Water, Land and Ecosystems (WLE), as well as Coordinator of the Global Groundwater Initiative GRIPP and a team member from UPGro GroFutures

From Thomson Reuters

New research reveals critical groundwater-related climate change impacts and resilience strategies

In 2014-2016, southern Africa saw its worst drought in decades, resulting from the most severe El Niño event in half a century. Leading to sharp declines in crop production, the drought dealt a severe blow to food security, with millions of people across the larger Pacific region facing hunger, poverty and disease.

Nature’s unseen water resource

While we all know groundwater is a key water resource for farmers, small communities and larger cities alike in  sub-Saharan Africa, it is largely missing from existing analysis of climate change impacts on water. Yet, Cape Town, which was greatly supported by groundwater development in its struggle to push back Day Zero when the city was projected to run out of water, shows us that groundwater is key to resilience.

But how does this unseen and relatively untapped resource in sub-Saharan Africa itself react to climate change? This may be the ultimate question as our water resources are finite, increasingly scarce and increasingly in demand. If African countries are to rely on groundwater for future resilience and manage it sustainably, they must quickly gain a better understanding of climate change impacts on this critical resource.

El Niño and extreme rainfall-triggered groundwater replenishment

recent study sheds new light on the climate-groundwater relationship, finding that the 2015-2016 El Niño weather event replenished groundwater very differently in southern Africa and in East Africa just below the equator. Based on a combination of satellite and on-site data analysis, it is part of a growing body of research, to which the International Water Management Institute (IWMI) is contributing, in collaboration with UK partners such as University College LondonCardiff UniversityUniversity of Sussex, and British Geological Survey, as well as others in southern and eastern Africa.

The El Niño-Southern Oscillation, or ENSO phenomenon, involves the interaction between the atmosphere and the ocean in the tropical Pacific. It is a telling cause of climate variability in the tropics. As an extreme case among historical patterns, the 2015-2016 event had exactly opposite effects on rainfall in southern Africa and East Africa below the equator.

In southern Africa, it resulted in the most intense drought ever recorded for the region, estimated to recur every 200 years.

The authors note that warming caused by human activities has heightened climate risks. They suggest that this has already “doubled the risk of such an extreme… event,” meaning such an intense drought could return every 100 years. The 2015-2016 drought limited the recharge of aquifers and increased demand for groundwater leading to a decline in groundwater storage.

In contrast, East Africa, just south of the equator, saw unusually high – but not extreme – rainfall, likely to recur every 10 years. With 100-150% above normal daily rainfall intensity in many places, this significantly boosted groundwater recharge and storage. At the Makutapora well field in Tanzania, for example, strong groundwater recharge reversed a long-term decline in groundwater storage that had resulted from increasingly intensive pumping to the growing city of Dodoma.

Another new study published in Nature underpins the importance of extreme rain events in restocking groundwater in drylands in sub-Saharan Africa. Rather than being replenished through regular rainfall, groundwater responds best to extreme rainfall events – the type that happens every 10 years or so, and is often associated with large scale climate phenomena like ENSO. The research also found that, since groundwater in drylands is recharged where rain accumulates in surface water bodies such as rivers and ponds, replenishment is further accentuated by more intense rainfall events associated with climate change.

Getting the better of climate change

Sub-Saharan countries are rapidly developing their groundwater resources, and these figure importantly in national development plans aimed at supplying cities with drinking water and enabling farmers to intensify production. Whether such plans come to fruition will depend on sustainable management of groundwater. Indeed, water managers need to understand how climate change impacts groundwater under different conditions and how they can best respond.

Techniques referred to as “managed aquifer recharge”, can channel and capture water runoff from intense rainfall events to more quickly and efficiently replenish groundwater. Thus, when climactic events increase rainfall, water managers and users across Africa can use such techniques to boost groundwater supply.

The extreme events can be predicted with some certainty and with seasonal lead times to help farmers and managers prepare. Combined with efficient resource use and safe wastewater reuse, communities and countries can better adapt to the more severe and frequent droughts, as well as floods, that are sure to come. With these approaches and opportunities, we can help harness the climate solutions that lie underground in the drylands in sub-Saharan Africa and beyond.

Extreme Floods, the Key to Climate Change Adaptation in Africa’s Drylands

By Isaiah Esipisu  for the Inter Press Service

Photo: A borehole in Kenya’s Turkana County. Experts say that groundwater in drylands is recharged through extreme floods. Credit: Isaiah Esipisu/IPS

TURKANA COUNTY, Kenya, Aug 8 2019 (IPS) – Extreme rainfall and heavy flooding, often amplified by climate change, causes devastation among communities. But new research published on Aug. 7 in the scientific journal Nature reveals that these dangerous events are extremely significant in recharging groundwater aquifers in drylands across sub-Saharan Africa, making them important for climate change adaptation.

Continue reading Extreme Floods, the Key to Climate Change Adaptation in Africa’s Drylands

Lord of the Rain: how radio can help African farmers combat drought

Today on the Guardian news website is an excellent short film “Lord of the Rain” that highlights the challenges facing farmers in the remote Omo region of Ethiopia.

Traditional knowledge is being challenged by climate change, and as the young man in the film says: “My dad predicts the weather with the traditional way, but I do it with science.”

The film shows how radio programmes are used to give vulnerable and remote communities access to reliable weather forecasts to help plan their planting or cattle movements.

Researchers in the UPGro BRAVE project are developing similar ways for remote communities in Northern Ghana and Burkina Faso. Bringing state-of-the-art climate, weather and groundwater monitoring and modelling to bear on the challenges facing these farmers: when is the best time to plant, when are their wells most likely to dry out.

In the village of Poa, Burkina Faso, researchers from the University of Reading, with local partners, including Christian Aid, have been monitoring groundwater responses to rainfall and working with farmers to understand the implications for their farming calendar – when to plant their onions, cabbages, tomatoes and aubergines.

Your can find out more about this work in Burkina Faso in this short report by Narcisse Ghahl, and the recent RWSN-UPGro webinar on communicating groundwater-climate behaviour with African farmers.

If you want to find out more about want is happening in Ethiopia, the UPGro GroFutures project is researching how groundwater can be used to improve rural livelihoods; and the REACH research programme is working on three aspects of water security, and recently published these guidelines on how to recruit and manage citizen scientists to measure water levels and flows, based on pioneering work in Ethiopia by the University of Newcastle.

And finally, if you want to delve more into the latest in African climate research, then visit Future Climate for Africa

Resilience of Rural Groundwater Supplies to Climate Change

Key Note Presentation by Prof. Alan MacDonald @ 1st SADC Groundwater Conference
Keywords: (Drought, Climate, Change, Infrastructure, Groundwater Resources, Resilience).

Alan

“Recent droughts have highlighted the need to understand and forecast the resilience of water supplies to climate variability. Resilience of groundwater supplies is determined by several factors: groundwater storage; long term recharge; permeability; and the infrastructure put in place to abstract groundwater.

“Drawing on recent research from across Africa, mainly funded through the UPGro programme, this talk examines the relative importance of each of these factors for rural drinking water supplies, and attempts to distinguish between the behaviour of the groundwater resource and the water infrastructure.

“A variety of data are presented and evaluated: detailed groundwater level monitoring of springs, wells and boreholes; national survey data of borehole functionality; groundwater residence time indicators; and also information from GRACE and global Land Surface Model.”

Source: Conference Abstract

Photo: SADC-GMI (via Twitter)

New paper helps unravel the mysteries of groundwater recharge in Benin

A new paper entitled: Relationships between rainfall and groundwater recharge in seasonally humid Benin: a comparative analysis of long-term hydrographs in sedimentary and crystalline aquifers has been published by the GroFutures team in collaboration with the GRIBA project (Groundwater Resources In Basement rocks of Africa), Belgian NGO – PROTOS, and Via Water in the Netherlands.

Key Points:

  • Groundwater Recharge – the set of processes that govern how rainwater seeps through soils and rocks to replenish aquifers – is not well understood across much of Africa. It is important to understand because it is central to determine the sustainable use of groundwater resources;
  • The authors analyse three rare sets of long-term (19-25 years) groundwater-level observations from three different, but common, geological settings in Benin;
  • The year-to-year changes in groundwater storage correlate well with rainfall patterns, but there were big differences the relate to the type of geology:
    • In the shallow, sand aquifer as much as 40% of the rainfall becomes groundwater
    • In the deeper sandstone and weathered crystalline rocks, a much lower proportion of rainfall becomes groundwater recharge (13% and 4% respectively)
  • Recharge was found to occur on a seasonal basis; however on a daily basis the groundwater fluctuations are best explained with a threshold of 5-15 mm per day – meaning that only more intense rainfall events lead to recharge.
  • These results are consistent with the growing body of evidence that, in Sub-Saharan Africa, intensification of rainfall associated with climate change may increase groundwater recharge.
  • Because the groundwater recharge is so strongly influenced by geology, it is essential for water resource planning that good geological maps are available and used, and that investment is made into long-term groundwater monitoring of strategic aquifers.