New state-of-the-art research collection on groundwater sustainability across Sub-Saharan Africa

An important new collection of papers has just been published online in the Hydrogeology Journal:

Substantial increases in groundwater withdrawals are expected across Sub-Saharan Africa to help nations increase access to safe water and to amplify agricultural production in pursuit of UN SDG 2 and SDG 6.  Long-term groundwater-level records or chronicles play an important role in developing an improved understanding of the hydrogeological and climatic conditions that control access and sustain well yields, informing where, when and how groundwater withdrawals can sustainably contribute to building resilience and alleviating poverty.

There are four papers in the collection (and an overview essay) that provide a sample of the new research outputs emanating from The Chronicles Consortium and UPGro GroFutures:

  • Evidence from chronicles in seasonally humid Benin and Uganda show annual cycles of replenishment from direct, diffuse recharge generated preferentially by heavy rainfalls. Kotchoni et al. show how chronicles from different geological environments in Benin can be modelled very effectively on a daily timestep with an improved watertable fluctuation model.
  • In semi-arid southwestern Niger, chronicles show that recharge to weathered crystalline rock aquifer systems occurs directly from rainfall but is restricted by a thick clayey aquitard developed from schist. However, greater recharge is shown to occur indirectly via riverbeds of ephemeral streams which provide preferential pathways through the saprolite.
  • Evidence from the Makutapora Wellfield of semi-arid central Tanzania that groundwater, abstracted at rates exceeding 30,000 m3/day, is sustained by episodic recharge associated with El Niño Southern Oscillation (ENSO). Further, abstracted groundwater is partially modern, derived from rainfall within the last 10–60 years.
  • Studies from Benin and Niger highlight the low storage of weathered crystalline rock aquifers and the importance of modern recharge in sustaining groundwater use. The low storage and low but highly variable hydraulic conductivity of weathered and fractured crystalline rock aquifers found over more than 40% of Sub-Saharan Africa may, however, have a potential advantage. Such aquifer systems restrict opportunities for intensive and competitive abstraction and are thus potentially self-regulating. Low-intensity groundwater abstraction distributed across the landscape also complements existing land-tenure systems in many areas of Sub-Saharan Africa dominated by smallholder agriculturalists.
  • The chronicles provide invaluable datasets to help direct assessments of past impacts of climate variability—e.g. ENSO, Atlantic Multi-decadal Oscillation (AMO)— and abstraction on groundwater storage. Such records, when continuously updated, can also provide key input to water resources management by tracking emerging risks to water security from groundwater storage decline or groundwater flooding (e.g. Murray et al. 2018).
  • Regional-scale (>50,000 km2) networks of long-term piezometric records can also be used to test the reliability of largescale, satellite observations from the Gravity Anomaly and Climate Experiment (GRACE). Indeed, the emergence of GRACE measurements of changes in total terrestrial water storage adds a potential tool, albeit at a much larger scale (>200,000 km2), to estimate changes in groundwater storage where records do not exist. However, there are substantial uncertainties from such estimates.

For full details read:

Please note that all five papers are open until 30 April, after which only 3 of the papers will be Open Access.

Text adapted from Topical Collection: Determining groundwater sustainability from long-term piezometry in Sub-Saharan Africa

The Baseflow Detective looking to uncover the secrets of Tanzania’s rivers

Interview with Hezron Philipo, GroFutures by Sean Furey, Skat Foundation

Hezron Philipo has a BSc in Geology (University of Dar es Salaam, Tanzania), MSc in Water Resources and Environmental Management (University of Twente at  ITC, The Netherlands) and is currently doing his PhD research at Sokoine University of Agriculture in Tanzania as part of the UPGro GroFutures project.

I caught up with him at 41st WEDC Conference in Nakuru, Kenya, where he explained the research that he is doing and what new insights him and his colleagues are uncovering.

Continue reading The Baseflow Detective looking to uncover the secrets of Tanzania’s rivers

Great potential for groundwater irrigation in Sub-Saharan Africa: Policy Brief by IWRA

re-posted from GRIPP

A new policy brief titled  Sustainable Groundwater Development for Improved Livelihoods in Sub-Saharan Africa was published by the International Water Resources Association (IWRA). Based on work carried out by IWMI and partners through the support of the Rockefeller Foundation and WLE, the brief describes the potential and constraints of groundwater irrigation Sub-Saharan Africa.

At least 400 million people in Sub-Saharan Africa source their domestic water supply from groundwater. Yet, this often abundant resource only accounts for around 20% of total irrigation. More widespread irrigation could help reduce rural poverty, improve food security, and counter droughts. The policy brief outlines why this water is untapped, and expands on three key policy messages:

  • There is great potential for groundwater irrigation in much of Sub-Saharan Africa
  • Smallholder farmers are eager to tap reliable new irrigation sources
  • The most critical constraints lie in developing supply chains, finance, and other essential infrastructure.

IWRA also identifies key Issues that need to be addressed:

  • Decentralized supply and maintenance of pumps
  • Smallholder access to reasonable financing options
  • Smallholder access to reliable and low-cost energy sources, particularly solar energy

The brief is based on research by International Water Management Institute (IWMI) and CGIAR Research Program on Water, Land and Ecosystems (WLE) and other partners. Download here.

GroFutures team bring rain to Niger in the dry season! (maybe…)

re-posted from GroFutures news


Speed Read:

  • Information collected through physical and social science methods was shared and discussed at the GroFutures Annual Workshop in Niger, with partners in and outside the study.
  • Open-source modelling software under FREEWAT platform was successfully piloted for ‘stress testing’ the sustainability of Groundwater Development Pathways accounting for climate and land-use change.
  • New water monitoring has been established to help manage the Iullemmeden Basin, which is shared by Niger and Nigeria

Continue reading GroFutures team bring rain to Niger in the dry season! (maybe…)

Is the Cape Town Time-bomb coming your way? Water Ministries and Operators need to do more to keep the water flowing

by Sean Furey (Skat) & Dr Anne Bousquet (GWOPA/UN-Habitat)

With water shortages in Cape Town, South Africa, hitting headlines worldwide, it was timely that the African Water Association (AfWA) convened their 19th Congress in Bamado, Mali around the theme of “Accelerating access to sanitation and water for all in Africa amidst the challenges of climate change”.

We were extremely fortunate that Dr Anne Bousquet of the Global Water Operators’ Partnerships Association (GWOPA) was able to attend and present the UPGro urban groundwater  study led by Prof. Stephen Foster last year. Her presentation was entitled “Groundwater – rational use to enhance urban water security under global change” [download presentation] .

Anne reflects on the presentation and the discussion with participants: Continue reading Is the Cape Town Time-bomb coming your way? Water Ministries and Operators need to do more to keep the water flowing

Poster presentations about work in Zambia and Kenya (Video)

At the IAH Congress, we asked two of the UPGro researchers to present their posters:

Jacob Mutua, Rural Focus Ltd, Kenya, describing the “Risks and Institutional Responses for Poverty Reduction in Rural Africa” Catalyst project

Dr Dan Lapworth talks about the project that he has been leading: “Mapping groundwater quality degradation beneath growing rural towns in SSA” in Zambia