Study shows boreholes are key to drought resilience in Ethiopia

BGS Press Release

Installing more boreholes to tap underground water will improve rural Ethiopian
communities’ resilience to drought, according to a new report.

Research carried out by the British Geological Survey (BGS), the University of Addis Ababa and the Overseas Development Institute (ODI) showed that people who have access to groundwater from boreholes are much less affected by drought than those who rely on wells or springs for their water supply. The report also links the shortage of water to:

  • conflict in local areas
  • migration
  • a decline in breastfeeding rates
  • a rise in miscarriage rates
  • more children missing school

Groundwater experts from the BGS monitored 19 hand-dug wells, springs and boreholes in two districts in northern Ethiopia over 18 months. They also held focus-group discussions with local people, including school and health centre staff, near each of the groundwater sources.

The team found that boreholes drilled to 50–100 m were the most reliable source of water during the extended drought of 2015–16 and through the dry season.

Prof Alan MacDonald, the BGS hydrogeologist who led the research, said: ‘We found that
boreholes equipped with hand pumps were more reliable than springs or hand-dug wells, and this reliability was not affected by drought or seasonal change. As hand-dug wells dried up and springs failed, the boreholes we monitored gave exactly the same flow throughout the year.

‘Boreholes also had better water quality. As the drought ended and rain started falling many of the springs and hand-dug wells became grossly contaminated. The boreholes performed much better, with less than half of them showing any level of contamination.

‘Our findings make a clear case for the installation of more boreholes to improve resilience to drought. If constructed carefully and regularly maintained, boreholes can transform the water security for rural villages and make them much more resilient to the effects of climate change.’

Dr Seifu Kebede, from Addis Ababa University’s earth sciences department, said:

‘A significant finding of our study is the length of time people without boreholes spent in water collection during the dry season and drought, and the very low volumes of water they were able to collect.

‘People were routinely queuing for up to 10 hours, which led to tension and sometimes violence, and had wide-ranging impact across communities. Women breastfed less and experienced more miscarriages, meals were missed and farm work was reduced to help collect water. School attendance was down in all but one district, as children were involved in water collection. All health centres in the study area reported increases in diseases, and, in some cases, employees were paying for water collection to keep the centres functioning.

‘We must look at how communities source water during a normal dry season to predict how they will cope during drought years. This study shows that boreholes, where they can be installed, could be the most reliable source of groundwater in these areas of northern Ethiopia.’

According to the BGS’s African Groundwater Atlas, Ethiopia has a high potential for groundwater in the highland regions due to the mostly permeable rocks. A major challenge, however, is the rugged terrain, which can hinder the movement of drilling rigs.

The project was funded by the Natural Environment Research Council (NERC) and the Department for International Development (DfID).

The full paper is available in Environmental Research Letters.

For further details please contact:
Sarah McDaid (sarah@mcdaidpr.co.uk/07866789688)
Twitter: @BritGeoSurvey


Editors note:

This week, groundwater experts from around the world will be attending a meeting of GRIPP at the SIWI World Water Week to discuss how to governments and aid agencies can take evidence like this into account when designing and implementing their policies and projects, and specifically around an exciting new groundwater initiative with the African Minister’s Council on Water (AMCOW)

Scientists look underground for a solution to feed the ever growing population in Africa

LISTEN NOW: Prof Richard Taylor, the Principal Investigator for the GroFutures project explains what the project is all about in SoundCloud interview.

Africa’s population is projected to hit 2.4 billion come the year 2050. This means that demand for food is going to increase exponentially. But the challenge is that this is happening in the wake of the changing climatic conditions with a threat of reduced agricultural productivity, and the shrinking of arable land due to tough climatic conditions, quest for development, and human settlement.

To bridge the gap, scientists among other experts have pointed out that there is urgent need for investment in irrigation. This was the magic bullet for the green revolution that took place in Asia.

But the question is; where will the water for irrigation come from?

This is because since the 1960s, during the green revolution in Asia, there has been depletion of the groundwater in many countries due to over abstraction, and this is already a huge crisis.

To ensure sustainability of groundwater use in Africa and to avoid mistakes made during the green revolution in Asia, UPGro scientists have taken the challenge first, to study and understand how different major aquifers on the continent recharge, how they respond to different climatic shocks and extremes, and they are already looking for appropriate ways of boosting the recharge for more sustainability.

Through a project known as Groundwater Futures in Sub-Saharan Africa (GroFutures), a team of 40 scientists from Africa and abroad have teamed up to develop a scientific basis and participatory management processes by which groundwater resources can be used sustainably for poverty alleviation.

Also read: Avoiding the Mistakes of the Asian Green Revolution in Africa

photo (Credit Grofutures: Combined Benin-Niger GroFutures field team with supporters working in Goulbi-Maradi (left); Early Career scientists under GroFutures, Fabrice Lawson (UAC/IRD, Benin), Jean-Baptist Gnonhoue (IRD, Benin), Rabilou Mahaman (UAMN, Niger), and Boukari Issoufou (UAMN, Niger) running MRS experiments in Goulbi-Maradi (right).)

 

Avoiding the Mistakes of the Asian Green Revolution in Africa

by Isaiah Esipisu (via the Inter Press Service)

DODOMA, Tanzania, Jul 11 2019 (IPS) – Research scientists are studying groundwater resources in three African countries in order to understand the renewability of the source and how people can use it sustainably towards a green revolution in Africa.

“We don’t want to repeat some of the mistakes during the green revolution that has taken place in Asia, where people opted to use groundwater, then groundwater was overused and we ended up with a problem of sustainability,” said Richard Taylor, the principal investigator and a professor of Hydrogeology from the University College London (UCL).

Through a project known as Groundwater Futures in Sub-Saharan Africa (GroFutures), a team of 40 scientists from Africa and abroad have teamed up to develop a scientific basis and participatory management processes by which groundwater resources can be used sustainably for poverty alleviation.

Though the study is still ongoing, scientists can now tell how and when different major aquifers recharge, how they respond to different climatic shocks and extremes, and they are already looking for appropriate ways of boosting groundwater recharge for more sustainability.

“Our focus is on Tanzania, Ethiopia and Niger,” said Taylor. “These are three strategic laboratories in tropical Africa where we are expecting rapid development of agriculture and the increased need to irrigate,” he told IPS.

In Tanzania, scientists from UCL in collaboration with their colleagues from the local Sokoine University of Agriculture, the Ministry of Water and Irrigation and the WamiRuvu Basin Water Board, have been studying the Makutapora well field, which is the only source of water for the country’s capital city – Dodoma.

“This is demand-driven research because we have previously had conflicting data about the actual yield of this well field,” said Catherine Kongola, a government official who heads and manages a sub section of the WamiRuvu Basin in Central Tanzania. The WamiRuvu Basin comprises the country’s two major rivers of Wami and Ruvi and covers almost 70,000 square kilometres.

She notes that scientists are using modern techniques to study the behaviour of groundwater in relation to climate shocks and also human impact, as well as the quality of the water in different locations of the basin.

“Groundwater has always been regarded as a hidden resource. But using science, we can now understand how it behaves, and this will help with the formulation of appropriate policies for sustainability in the future,” she told IPS.

Already, the World Bank in collaboration with the Africa Development Bank intends to invest some nine billion dollars in irrigation on the African continent. This was announced during last year’s Africa Green Revolution Forum that was held in Kigali, Rwanda.

According to Rajiv Shah, the president of the Rockefeller Foundation, boosting irrigation is key to improving agricultural productivity in Africa.

“In each of the areas where we are working, people are already looking at groundwater as a key way of improving household income and livelihoods, but also improving food security, so that people are less dependent on imported food,” said Taylor. “But the big question is; where does the water come from?”

Since the 1960s, during the green revolution in Asia, India relied heavily on groundwater for irrigation, particularly on rice and wheat, in order to feed the growing population. But today, depletion of the groundwater in the country has become a national crisis, and it is primarily attributed to heavy abstraction for irrigation.

The depletion crisis remains a major challenge in many other places on the globe, including the United States and China where intensive agriculture is practiced.

“It is based on such experiences that we are working towards reducing uncertainty in the renewability and quantity of accessible groundwater to meet future demands for food, water and environmental services, while at the same time promoting inclusion of poor people’s voices in decision-making processes on groundwater development pathways,” said Taylor.

After a few years of intensive research in Tanzania’s Makutapora well field, scientists have discovered that the well field—which is found in an area mainly characterised by seasonal rivers, vegetation such as acacia shrubs, cactus trees, baobab and others that thrive in dry areascan only be recharged during extreme floods that can also destroy agricultural crops and even property.

“By the end of the year 2015, we installed river stage gauges to record the amount of water in the streams. Through this, we can monitor an hourly resolution of the river flow and how the water flow is linked to groundwater recharge,” Dr David Seddon, a research scientist whose PhD thesis was based on the Makutapora well field, told IPS.

Taylor explains that Makutapora is known for having the longest-known groundwater level record in sub-Saharan Africa.

“A study of the well field over the past 60 years reveals that recharge sustaining the daily pumping of water for use in the city occurs episodically and depends on heavy seasonal rainfall associated with El Niño Southern Oscillation,” Taylor said.

According to Lister Kongola, a retired hydrologist who worked for the government from 1977 to 2012, the demand for water in the nearby capital city of Dodoma has been rising over the years, from 20 million litres in the 1970s, to 30 million litres in the 1980s and to the current 61 million litres.

“With most government offices now relocating from Dar Es Salaam to Dodoma, the establishment of the University of Dodoma, other institutions of higher learning and health institutions, and the emergence of several hotels in the city, the demand is likely going to double in the coming few years,” Kongola told IPS.

The good news, however, is that seasons with El Niño kind of rainfall are predictable. “By anticipating these events, we can seek to amplify them through minimal but strategic engineering interventions that might allow us to actually increase replenishment of the well-field,” said Taylor.

According to Professor Nuhu Hatibu, the East African head of the Alliance for a Green Revolution in Africa, irrigation has been the ‘magic’ bullet for improving agricultural productivity all over the world, and “that is exactly what Africa needs to achieve a green revolution.”

 

Photo: Richard Taylor, a Professor of Hydrogeology from the University College London (UCL) (far left) is the principal investigator in a project to study groundwater resources to understand more how to use the resource to alleviate poverty. Credit: Isaiah Esipisu/IPS

UPGro T-Group research finds cancer-causing viruses in Kampala and Arusha slum groundwater

by Isaiah Esipisu and Dr Jan Willem Foppen (T-GroUP)

In Summary

  • The study found that most groundwater in the two slums contains traces of herpes virus, poxvirus and papilloma virus.
  • Cancer is one of the top killer diseases in East Africa, blamed for nearly 100,000 deaths every year.

Watch EGU press-conference presentation by Dr Foppen (start 18:00 minutes into recording)

Researchers from IHE Delft Institute for Water Education and their peers from Uganda and Tanzania have found traces of 25 DNA virus families — some of them with adverse health risk for humans — in underground water in the slums of Kampala and Arusha.

The study, whose findings were presented at the Assembly of the European Geosciences Union in Vienna on Monday, found that most groundwater in the two slums contains traces of herpes virus, poxvirus and papilloma virus.

CANCER

The latter could be one of the causes of cancer in East Africa.

“These viruses have never been found on such a large scale in ground water. Perhaps it is because there has never been an in-depth analysis,” said Dr Jan Willem Foppen, one of the lead researchers and a hydrologist at the IHE Delft — the largest graduate water education institution on the planet.

Cancer is one of the top killer diseases in East Africa, blamed for nearly 100,000 deaths every year.

According to the latest report by the International Agency for Research on Cancer, some 32,617 new cases were reported in Uganda last year, with 21,829 deaths.

32,617 DEATHS

In the same period, Kenya recorded 47,887 new cases and 32,987 deaths while there were 42,060 new cases in Tanzania with 28,610 deaths.

Scientists have therefore expressed concerns that the widespread use of groundwater in slums for cooking, cleaning and bathing poses a risk for the residents.

In the two-year study, the scientists analysed surface water (river and drain), spring water, wells and piezometers (groundwater from specific depth) in the three countries.

“We found 25 DNA virus families, of which 14 are from above ground hosts like frogs, mice, rats, cows, horses, monkeys and humans,” Dr Foppen said.

DISEASES

Of the human disease causing pathogens found in the samples, herpes virus and poxviruses can lead to skin infections while the papilloma cause some types of cancers such as cervical, laryngeal and mouth.

“This could be just a tip of the iceberg. We have not found all the viruses. We found the most abundant ones,” Dr Fopen said.

“Let’s do something about sanitation. Let us improve our sources of drinking water and identify new pathways with communities towards sustainability.”

Versions of this article have been published in:

Further papers and data will be published soon.

Fossil groundwater vulnerable to modern contamination

Study shows that over half of global groundwater is over 12,000 years old

Most of the groundwater in the world that is accessible by deep wells is fossil groundwater, stored beneath the earth’s surface for more than 12,000 years, and that ancient water is not immune to modern contamination, as has been widely assumed.

This study, led by Dr. Scott Jasechko (University of Calgary) and co-authored by an international team of researchers including Professor Richard Taylor (UCL Geography & UPGro GroFutures), is published online today (April 25) in Nature Geoscience.

Groundwater is the water stored beneath the earth’s surface in soil pore spaces and within the fractures of rock formations. It provides drinking and irrigation water for billions of people around the world.

Jasechko, Taylor and his co-researchers dated groundwater from over 6,000 wells around the globe. By measuring the amount of radioactive carbon in the water, the team was able to determine the age of the groundwater. They discovered that the majority of the earth’s groundwater is likely fossil groundwater, derived from rain and snow that fell more than 12,000 years ago. The team determined that this fossil groundwater accounts for between 42 to 85 per cent of total fresh, unfrozen water in the upper kilometre of the earth’s crust.

Until now, the scientific community has generally believed that fossil groundwater is safe from modern contamination but this study has proved otherwise.

“Deep wells mostly pump fossil groundwater but many still contain some recent rain and snow melt, which is vulnerable to modern contamination,” says Jasechko.

Rain and snow that fell after the 1950s contains tritium, a radioactive isotope that was spread around the globe as a result of thermonuclear bomb testing. Disturbingly, traces of tritium were found in deep well waters, which indicates that contemporary rain and snow melt can mix with deep fossil groundwater and, in turn, potentially contaminate this ancient water.

According to Taylor, this discovery has important ramifications that should influence the way humans use groundwater in the future,

“Our results reveal not only current use of fossil groundwater but also the potential risks to water quality associated with the use of deep wells. Indeed, we need to better understand how the construction and pumping of deep wells themselves may connect fossil groundwater to the present-day water cycle.”

Scale of global water crisis could be unknown due to inadequate metrics, study suggests #worldwaterday

Re-posted from UCL

A new study by UCL researchers exposes substantial limitations in the ability of current metrics to define ‘water scarcity’.

 

21 March 2017

A new study by UCL suggests the scale of the global water crisis could not be properly known at due to inadequacies with the current metrics used to measure it.

With today being World Water Day, the research, led by the UCL Institute for Sustainable Resources and UCL Geography, exposes substantial limitations in the ability of current metrics to define ‘water scarcity’.

The report finds that the misrepresentation of freshwater resources and demand is particularly severe in low-income countries of the tropics where the consequences of water scarcity are projected to be most severe and where most of the global population now live. Simply put, the authors argue that we do not know the dimensions of the global water crisis.

Ensuring the availability of adequate quantities of freshwater to sustain the health and well-being of people and the ecosystems in which they live, remains one of the world’s most pressing challenges. This question is reflected in UN Sustainable Development Goal 6.4 which seeks to reduce the number of people suffering from water scarcity.

The authors call for a renewed debate about how best to measure ‘water scarcity’ and argue that it be redefined in terms of the freshwater storage required to address imbalances in freshwater supply and demand. Such an approach, they contend, would enable for the explicit consideration of groundwater, the world’s largest accessible store of freshwater which accounts for nearly 50% of all freshwater withdrawals globally.

Further the authors suggest that such a metric could be used pragmatically to explore a wide range of options for addressing freshwater storage requirements beyond dams alone that include use of renewable groundwater, soil water, and trading in virtual water.

Prof Richard Taylor, co-author of the paper says:

“How we understand water scarcity is strongly influenced by how we measure it. Grossly misrepresentative measures of water scarcity can identify scarcity where there is sufficient and sufficiency where there is scarcity. An improved measure of water scarcity would help to ensure that limited resources are better targeted to address where and when water-scarce conditions are identified.”

Click here to download the paper

Authors:

Simon Damkjaer, UCL Institute for Sustainable Resources
Prof Richard Taylor, UCL Department of Geography

UPGro GroFutures: http://grofutures.org/

Photo: Irrigated maize crop supplied by groundwater in Zambia – Richard Taylor

New pollution risk maps for Africa to help with achieving safe water for everyone

Africa_Risk_map

Media Release: World Water Day 22 March

New pollution risk maps for Africa to help with achieving safe water for everyone.
Responding to UNICEF/WHO report on Safely managed drinking water

The United Nations Children’s Fund (UNICEF) and the World Health Organisation (WHO) have published a key Joint Monitoring Programme (JMP) report on “Safely managed drinking water”[1]. It explains the way that the progress in improving drinking water will be measured across the world in pursuit of the Sustainable Development Goal Target 6.1 of achieving universal and equitable access to safe and affordable drinking water for all by 2030[2]. This is an immensely challenging target, particularly in many countries in Sub-Saharan Africa, which failed to reach the Millennium Development Goal Target of halving the number of people without access to an “improved” water source between 1990 and 2015.

For governments, aid agencies and citizens, a key question has been – what do we mean by “safe” water? This new JMP report starts to provide some of those answers. They define it to mean water that is “free from pathogens and elevated levels of toxic substances at all times”.  For many areas, the most accessible safe water is from the ground – from boreholes, wells and springs. But this is not the case everywhere.

There is no question about the importance of groundwater in sub-Saharan Africa, where it provides drinking water supplies for at least 170 million people. In comparison with surface water, groundwater is widely known for its greater reliability, resilience to climate variations and reduced vulnerability to pollution. However, groundwater contamination does occur when waste from households, municipalities, livestock, agriculture, hospitals and industries (including mining) is able to make its way Inadequate management of household and industrial waste is leading to the pollution of groundwater resources in urban centres in sub-Saharan Africa.

In a new landmark study just published[3], reviewed all the available data and studies on urban groundwater across the continent and build up a map of aquifer pollution risk (Fig. 1)

The lead researcher, Dr Daniel Lapworth, of the British Geological Survey, said: “Despite the risk to the health of millions of people across the continent, very little is routinely monitored. If there is any chance of achieving the Sustainable Development Goal targets – and adapting to climate change – it is essential that governments and water utilities routinely monitor groundwater quality and take appropriate action to protect their precious water resources.”

“However, we are excited that our research through has developed a low-cost and robust way for measuring groundwater quality[4], and this approach is being rolled out in our work in Africa and India.”

Africa_Risk_map
Fig. 1: Relationship between urban centres in sub-Saharan Africa (SSA) and estimated aquifer pollution risk using an intrinsic aquifer modelling approach (Ouedraogo et al. 2016). The location of studies included in the paper are shown. Major cities in SSA are shown and are from the ESRI cities dataset (2006)

More information

UPGro is funded by UK Aid; the UK Natural Environment Research Council (NERC); and the UK Economic and Social Research Council (ESRC). Knowledge Broker: Skat Foundation, in partnership with the Rural Water Supply Network (RWSN) www.rural-water-supply.net

For more information:

NERC media office
01793 411939 / 07785 459139 /  pressoffice@nerc.ac.uk

More details can be found on http://upgro.org ; The Knowledge Broker for UPGro is Skat Foundation, based in St Gallen, Switzerland. Contact: Sean Furey (sean.furey@skat.ch ) for more information.

[1] https://data.unicef.org/resources/safely-managed-drinking-water/

[2] https://sustainabledevelopment.un.org/sdg6

[3] Lapworth, D.J., D. C. W. NkhuwaJ. Okotto-OkottoS. PedleyM. E. StuartM. N. TijaniJ. Wright “Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health” Hydrogeol J (2017). doi:10.1007/s10040-016-1516-6

[4] Sorensen J, D.J. Lapworth, B.P. Marchant, D.C.W. Nkhuwa, S. Pedley, M.E. Stuart, R.A. Bell, M. Chirwa, J. Kabika, M. Liemisa, M. Chibesa (2015) “In-situ tryptophan-like fluorescence: A real-time indicator of faecal contamination in drinking water supplies” Water Research, Volume 81, 15 September 2015, Pages 38–46

Africa Groundwater Atlas: “X” marks the spot, but where’s the map? #60IAH2016

Drilling for water is a fraught business in Africa – like being a pirate without a treasure map. In many areas, the rock is old – some of the oldest on our planet. This cracked, shattered stone that is blasted by desert heat or soaked in tropical rains with often only a thin covering of rust-stained soil, can hold substantial amounts of water, but a driller needs to know where to look and the skill to develop a water source that will last. A metre or two can make the difference between a dry hole and a well that could supply a village or a farm for a lifetime.

Continue reading Africa Groundwater Atlas: “X” marks the spot, but where’s the map? #60IAH2016

Cultiver les données : comment les agriculteurs éthiopiens récoltent les données pour favoriser leurs semis #60IAH2016

Quel temps va-t-il faire ? Beaucoup de gens se posent la question, mais pour beaucoup d’Éthiopiens la réponse peut faire la différence entre affluence et pauvreté. L’Èthiopie est un pays riche et divers de près de 100 millions d’habitants, 88 langues différentes et une histoire ancienne et remarquable. Ses hauts plateaux sont humides et fertiles lors de la saison des pluies, alors que ses plaines désertiques comptent parmi les endroits les plus arides de la Terre.

Dangila woreda (district) est une zone montagneuse dans le nord ouest du pays avec une population de 160 000 personnes environ répartie sur 900 km2. Bien que la zone recoive 1 600mm de précipitations annuelles, plus de 90% des pluies ont lieu entre mai et octobre. Les agriculteurs, qui dépendent de leurs troupeaux et de leurs cultures pluviales, doivent absolument comprendre et prévoir les variations de précipitations pour assurer leur ubsistance. Les statégies traditionnelles, utilisées depuis des millénaires, sont menacées par les effets conjugués des changements climatiques, de la dégradation des sols et de la croissance démographique.

Le manque de données sur les précipitations, le débit des eaux de surface et le niveau des eaux souterraines empêche de savoir exactement ce qui passe actuellement et ce qui pourrait arriver ensuite. Dans la majeure partie de l’Afrique sub-saharienne, les gouvernements n’ont pas assez investi dans le suivi-évaluation des conditions environnementales, qui décline et rend de plus en plus difficile la gestion des ressources en eau.

Et si c’étaient ceux qui ont le plus à gagner d’une compréhension et d’une gestion améliorée des ressources en eau qui pilotaient la collecte des données ? Les communautés sont-elles capables de collecter des données fiables sur la météo, les riviéres et les eaux souterraines ? C’est ce qu’explore une équipe de chercheurs de l’Université de Newcastle au Royaume Uni avec le projet AMGRAF[i] financé par UPGro[1].

Dans une nouvelle publication dans le Journal of Hydrology, David Walker et ses collègues expliquent pourquoi ils pensent que la science citoyenne a un avenir dans les zones rurales d’Èthiopie et au delà :

« Les bénéfices de la participation des communautés aux démarches scientifiques sont progressivement reconnus dans plusieurs disciplines, notamment parce que cela permet au grand public de mieux comprendre la science et de mieux s’approprier les résultats, avec une certaine fierté même. Et cela sert à la fois les individus et les processus de planification locaux. » précise Walker. « Parce qu’il y a si peu de stations de suivi-évaluation officielles, et que les zones à étudier et à gérer sont si vastes, il nous faut penser à d’autres méthodes de collecte des données. »

Le programme de suivi-évaluatio communautaire a démarré en février 2014 et les habitants d’une zone appellée Dangesheta ont été impliqués dans l’implantation de nouvelles jauges pluviométriques et de rivières et dans l’identification des puits adéquats pour le suivi. Cinq puits sont jaugés manuellement tous les deux jours, avec une mesure de la profondeur et du niveau d’eau ; une jauge pluviométrique a été installée dans la métairie d’un résident qui effectuait les relevés quotidiennement à 9h ; deux jauges ont été installées sur les rivières Kilti et Brante et étaient relevés tous les jours à 6h et 18h. Chaque mois, les bénévoles remettaient le registre de leurs relevés au bureau du Dangila woreda district, qui les saisissait dans un fichier excel et les envoyait ensuite à l’équipe de recherche.

Mais ces données sont-elles fiables ? Pour David et ses collègues, c’était une question déterminante pour le succès ou l’échec du projet. La validation des données est toujours un défi, qui souffre généralement de deux types d’erreurs :

Les erreurs d’échantillonage proviennent de la variabilité des pluies, du débit des eaux de surface et du niveau des eaux souterraines dans le temps et dans l’espace. Ce type d’erreur augmente avec les précipitations et diminue avec une plus grande densité de jauges. Le défi dans les zones tropicales comme l’Éthiopie c’est que la plupart de la pluie tombe sous la forme d’orages diluviens, qui peuvent être assez courts et petits et donc faciles à rater, ou bien seulement partiellement relevés, si la densité des stations météo est faible.

Le deuxième type d’erreurs sont les erreurs d’observation, qui peuvent avoir plusieurs causes : des vents forts renversant la jauge, l’évaporation vidant la jauge, et bien sûr l’observateur qui peut ne pas  lire la jauge  correctement ou bien mal transcrire ses observations.

« C’est compliqué de relever les erreurs mais c’est possible, surtout en faisant des comparaisons statistiques avec les résultats de stations météo et d’autres sources bien établies» confie Walker. « Nous constatons que les données collectées par les communautés sont plus fiables que celles collectées par télédétection satellite. »

Nous espérons que cette approche prometteuse sera davantage soutenue et sera utilisée plus largement, mais quels sont les secrets et les défis d’une participation communautaire réussie ?

 

« Les gens sont au cœur du processus, donc la sélection des bénévoles est une étape fondamentale pour éviter la falsification des données ou le vandalisme » conclut Walker. « Les retours sur les résultats sont aussi absolument cruciaux: les données peuvent être présentées et analysées avec la communauté lors d’ateliers ou de réunions collectives, leur permettant ainsi de prendre des décisions sur la meilleure utilisation des précipitations, des eaux de surface et des eaux souterraines pour garantir l’approvisionnement en eau de leurs fermes et de leurs familles. »

Ces travaux de recherche se poursuivent grâce à une bourse[2] de REACH : Améliorer la sécurité hydrique pour les populations pauvres, un programme piloté par l’Université d’Oxford.

[1]               « UPGro – Libérer le potentiel des eaux souterraines pour les populations pauvres » est un programme de recherche international de 7 ans (2013-2019) qui est co-financé par le Département pour le développement international (DFID) du Royaume Uni, le Conseil de Recherche pour l’environnement naturel (NERC) et le Conseil de Recherche Economique et Sociale (ESRC). Il vise à renforcer et améliorer les données factuelles sur la disponibilité et la gestion des eaux souterraines en Afrique Sub-Saharienne (ASS), afin de permettre aux pays en développement de la région et à leurs partenaires d’utiliser ces eaux souterraines de façon durable au bénéfice des populations pauvres. Les projets UPGro sont interdisciplinaires, liant sciences sociales et sciences naturelles pour relever ce défi.

[2]               http://reachwater.org.uk/grants-catalyse-12-new-water-security-projects/

[i]               AMGRAF: Adaptive Management of GRoundwater for small scale-irrigation and poverty alleviation in sub-Saharan AFrica: https://upgro.org/catalyst-projects/amgraf/ and http://research.ncl.ac.uk/amgraf/

Data farming – how Ethiopian farmers harvest data to help their crops

What’s the weather doing? It’s a question that obsesses many but for many Ethiopians it is question that makes the difference between plenty and destitution.  Ethiopia is a rich and diverse country that is home to around 100 million people, 88 different languages and imbued with long, diverse history. Its highlands are seasonally wet and fertile and its lowland deserts are among the most parched places on Earth.

Dangila woreda, or district, is a hilly area in the north west of the country with a population of around 160,000 people spread across an area of about 900 km2. Although the area receives rainfall at around 1,600mm a year, over 90% of this falls between May and October.  For farmers, who depend on livestock and rainfed crops, understanding and predicting these rains is crucial to their livelihoods. Traditional strategies, which have served for millennia, are coming under threat from new pressures of shifting climate patterns, land degradation and population growth.

Exactly what is happening now and what is likely to happen in the future is uncertain due to the lack of rainfall, river flow and groundwater level data.  Throughout much of Sub-Saharan Africa, under-investment by governments has led to a widespread decline in environmental monitoring, and this in turn makes water resources management harder and harder.

But what if those who stood to gain most from better understanding and management of water resources were those leading the data collection? Can communities reliably collect accurate weather, river and groundwater data? This is the question that is being investigated by researchers, led by Newcastle University in the UK through an UPGro-supported[i] project called AMGRAF[ii]).

In a new paper in the Journal of Hydrology[iii], David Walker and his colleagues explain why they think citizen science has a future in rural Ethiopia and beyond:

“The benefits of community involvement in science are being slowly recognised across many fields, in large part because it helps build public understanding of science, ownership and pride in the results, and this can benefit both individuals and local planning processes,” said Walker.  “Because there are so few formal monitoring stations and such large areas that need to be understood and managed, we need to think differently about how data collection can be done.”

The community-based monitoring programme was started in February 2014 and residents of an area called Dangesheta were involved in the siting new rain and river gauges, and identifying wells that were suitable to be monitored.  Five wells are manually dipped every two days, with a deep meter to measure the depth from the ground surface and the water level in the well; a rain gauge was installed in the smallholding of a resident who then took measurements every day at 9am; two river gauge boards were installed in the Kilti and Brante rivers and were monitored daily at 6am and 6pm. Every month, the volunteers would then give their hard copy records to the Dangila woreda government office, who then typed them into an Excel spreadsheet and emailed to the research team.

But is this data any good? For David and his colleagues, this was a critical question that could make or break the whole approach.  The challenges of data validation are substantial, and there are generally two types of error:

Sampling errors come from the variability of rainfall, river flow and groundwater level over time and over area. The sampling error increases with rainfall and decreases with increased gauge density. A challenge in tropical areas, such as Ethiopia, is much of the rain is high-intensity thunderstorms, which can be quite short in duration and small in size, and therefore easy to miss, or only partially record, if the density of monitoring stations is low.

Observational errors are the second type, and can come from a number of things:  wind turbulence, splashing around the gauge, evaporation can affect how much is in the rain gauge, and then the observer might not read the gauge accurately or make a mistake or unclear notation, when writing the measurement down.

“Tracking down errors is tricky, but it can be done, mainly through statistical comparison with established monitoring stations and with each other,” said Walker. “What we found was that the community collected data is more reliable than that gathered through remote sensing instruments from satellites.”

It is hoped that this promising approach can attract further support and be used more widely, but what are the secrets, and challenges, to making community monitoring work?

“People are at the heart of this process and selection of volunteers is crucial to avoid problems with data falsification or vandalism,” concluded Walker.  “Feedback is absolutely vital and through workshops and meetings the data can be presented and analysed with the community so that they can make decisions on how best use the available rainfall, river flows, and groundwater to provide secure sources of water for their farms and their homes.”

 

Research continues through a research grant[1] from REACH: Improving water security for the poor, a programme led by Oxford University.

Figure 1:

[1] http://reachwater.org.uk/grants-catalyse-12-new-water-security-projects/

[i] “UPGro – Unlocking the Potential of Groundwater for the Poor” is a seven-year international research programme (2013-2019) which is jointly funded by UK’s Department for International Development (DFID), Natural Environment Research Council (NERC) and in principle the Economic and Social Research Council (ESRC). It focuses on improving the evidence base around groundwater availability and management in Sub-Saharan Africa (SSA) to enable developing countries and partners in SSA to use groundwater in a sustainable way in order to benefit the poor. UPGro projects are interdisciplinary, linking the social and natural sciences to address this challenge. T

[ii] AMGRAF: Adaptive Management of GRoundwater for small scale-irrigation and poverty alleviation in sub-Saharan AFrica: https://upgro.org/catalyst-projects/amgraf/ and http://research.ncl.ac.uk/amgraf/

[iii] D. Walker et al, “Filling the observational void: Scientific value and quantitative validation of hydrometeorological data from a community-based monitoring programme” Journal of Hydrology 538 (2016) 713-725 http://www.sciencedirect.com/science/article/pii/S0022169416302554