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

Community river monitoring in Dangila woreda, Ethopia (D. Walker, Newcastle University)

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

Community river monitoring in Dangila woreda, Ethopia (D. Walker, Newcastle University)

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

African aquifers can protect against climate change

Groundwater storage for Africa based on the effective porosity and saturated aquifer thickness. Panel (a) shows a map of groundwater storage expressed as water depth in millimetres with modern annual recharge for comparison (Döll and Fiedler 2008). Panel (b) shows the volume of groundwater storage for each country; the error bars are calculated by recalculating storage using the full ranges of effective porosity and thickness for each aquifer, rather than the best estimate. Annual renewable freshwater availability (FAO 2005) generally used in water scarcity assessments is shown for comparison (from MacDonald 2012)

Floods and droughts, feasts and famines: the challenge of living with an African climate has always been its variability, from the lush rainforests of the Congo to the extreme dry of the Sahara and Namib deserts. In north western Europe, drizzle and rain is generally spread quite evenly across the year, as anyone who has gone camping in British summer will tell you. But when annual rainfall happens within just a few months or weeks of the year then it is a massive challenge for farmers, towns and industry to access enough water through long dry seasons and to protect themselves and their land from flooding and mudslides when the rains come.

New research[1] suggests that Africa’s aquifers could be the key to managing water better. Professor Richard Taylor at UCL explains: “What we found is that groundwater in tropical regions – and Sub-Saharan Africa in particular – is primarily replenished from intense rainfall events – heavy downpours. This means that aquifers are an essential way of storing the heavy rain from the rainy season for use during the dry season, and for keeping rivers flowing.”

Continue reading African aquifers can protect against climate change

Tropical groundwater resources resilient to climate change

Tropical groundwater may prove to be a climate-resilient source of freshwater in the tropics as intense rainfall favours the replenishment of these resources, according to a new study published in Environmental Research Letters.

Continue reading Tropical groundwater resources resilient to climate change

Collecting Water With Roads – ground-breaking research wins Global Environment Award

Water is short in many places but roads are everywhere – and when it rains it is often along these roads that most water runs, as roads unknowingly either serve as dike or a drain. By harvesting the water with these roads, water shortage can be overcome and impacts of climate change can be mitigated.

This was the idea behind the UPGro Catalyst Grant research[1],[2] project undertaken in 2013-2014 in Tigray Regional State in Ethiopia. The research looked at ways and means of collecting water with the roads – from culverts, drains, borrow pits, road surface, river crossings, as these have massive impact on how rain run-off moves across a landscape.

The idea then scaled up quickly – in 2014 the Tigray Government implemented road water harvesting activities in all its districts.

The results have been spectacular in increased water tables, better soil moisture, reduced erosion from roads, less local flooding and moreover much better crop yields.

It is for this project that MetaMeta of the Netherlands, together with its partners Mekelle University and Tigray Government have been awarded this week the prestigious Global Road Achievement Award for Environmental Mitigation[3] by the International Roads Federation. Among the other award winners are the people who are constructing one of the world‘s largest bridges in China. The potential to scale up the use of water with roads is enormous – with every area having its own solutions.

There is also a compelling economic case: harvesting water with roads if done well greatly reduces water damage to roads. The scaling up of the concept is now being undertaken with support of the Global Resilience Partnership[4] (supported by USAID, Rockefeller Foundation and SIDA), where MetaMeta with its partners are a Stage 2 winner. Programmes to collect the water from the roads are being undertaken in more areas now – such as in Amhara Regional State, where it is part of the massive programme to prepare for the expected El Niño climate event. More than two million people are being mobilised for water harvesting activities, including from the roads.

MetaMeta and Mekelle University would welcome those interested to become part of the learning alliance which will bring together on-going experiences and give access to training materials that are being developed – those interested in the learning alliance can mail to marta@metameta.nl

Further information:[5]

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

Press release: 02/07/2015 (a) Example of bad road drainage, Tigray, Ethiopia (Photo: Mekelle University, 2014) (b) Examples of roadside ponds to capture water and protect the road, Tigray, Ethiopia (Photos: Mekelle University, 2014) [1]Optimising Road Development for Groundwater Recharge and Retention” was one of fifteen UPGro ‘Catalyst’ projects. More details on this project can be found at http://roadsforwater.org [2] “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. They will be delivered through collaborative partnerships of the world’s best researchers. The programme’s success will be measured by the way that its research generates new knowledge which can be used to benefit the poor in a sustainable manner. [3] Winners of the 2015 GRAA Competition https://www.irfnews.org/graa/ [4] Connecting Roads, Water and Livelihoods for Resilience: http://www.globalresiliencepartnership.org/teams/roads-water-livelihoods/ [5] 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.

Roads for Water – new research puts Ethiopian farmers in the driving seat

Media Release

World Water Day is an opportunity to reflect on the immense challenge that faces millions of people every day. Much of Sub-Saharan Africa, in particular, is notably off-track from the Millennium Development Goals[i], which come to an end this year.

Yet hope is emerging from unexpected directions: the UK is leading pioneering research into how the un-tapped potential of Africa’s groundwater can be used sustainably and for the benefit of the poorest and most marginalised peoples.

Farmers diverting water from a culvert into a percolation pond for supplementary irrigation and groundwater recharge in Tigray, Ethiopia
Farmers diverting water from a culvert into a percolation pond for supplementary irrigation and groundwater recharge in Tigray, Ethiopia
Road construction affects the hydrology of an area; causes erosion, flooding, water logging (photo: Meta Meta Research)
Road construction affects the hydrology of an area; causes erosion, flooding, water logging (photo: Meta Meta Research)

Continue reading Roads for Water – new research puts Ethiopian farmers in the driving seat