Groundwater recharge in Africa: identifying critical thresholds

Lead Research Organisation: NERC British Geological Survey
Department Name: Groundwater

Abstract

The development of groundwater for safe drinking water, irrigation and other uses offers huge potential for improving the lives of many African people. Recent research showed that groundwater was present in most parts of Africa and represented a resource greater than the water available in lakes and rivers. However, a key uncertainty is how sustainable groundwater abstraction will be: is it being replenished and if so by how much and will this change in the future?

This research project will bring together a team of African, European and US scientists to examine all the available evidence for groundwater recharge across Africa. The team will use these data to search for the existence of critical recharge thresholds: conditions beyond which recharge may not occur or become unreliable. They will use the datset to develop a map of observed groundater recharge volumes for Africa and look for systematic changes across the continent. The team will also use the opportunity to examine the different methods for measuring groundwater recharge and identify the most appropriate for African conditions.

Together with social scientists they will use the results of the research to highlight areas and future scenarios where groundwater recharge may become a major contraint on sustainable groundwater abstraction, and where wells or boreholes may run dry, impacting particularly on the rural poor. The maps of groundwater recharge, and the quantification of critical thresholds can have many different uses: they should help quantify the risks of groundwater development and manage tradeoffs in abstraction for the benefit of the poor; for water engineers working in Africa, they should allow a first pass assessment of groundwater recharge to screen whether recharge may be a major constraint on a project, and also provide the tools for measuring recharge more accurately; for the academic community these new datasets can be used to validate global or continetal scale land surface hydrological models. Once the research is completed a workshop and webinar convened by WaterAid will help explore the implications of the research results for planning and implementing new water projects in Africa.

The results of this research will be used as a springboard to design a large field programme of interdisciplinary research to examine the processes which lead to these critical recharge thresholds to allow much more reliable forecasts of where groundwater development may become unsustainable in the future and to explore how groundwater can be best managed in these critical areas.

Planned Impact

The results of this research have the potential to have a significant and widespread impact, which ultimately should lead to the sustainable development and management of groundwater for the poorest within Africa. A strategy has been developed to help the research influence water policy in Africa, be taken up by water practitioners and professionals and be used by the wider academic community for other uses, such as validating global models (see the pathwway to impact attachment). The research will also help build capacity within African research community.

1. Ultimate beneficiaries of the research
Many of the improved water services in Africa rely on groundwater, and efforts to supply 344 million without access to secure water services will also largely depend on groundwater. Sustainable groundwater development has the potential to contribute to reducing poverty across Africa by providing secure drinking water supplies for all, particularly the poor who have little alternative. However, for groundwater development to continue to provide benefits for the poor it needs to be regularly recharged by rainfall. This research will provide information and data on how groundwater recharge varies across the continent and what critical thresholds exist which could significantly alter recharge volumes and timing. Therefore, with increasing abstractions of groundwater forecast for both domestic and agricultural uses, this research has the potential to provide quantitative information to help make informed decisions on how to manage tradeoffs in abstraction for the benefit of the poorest.

2. Research users
The research outputs will be in various forms to make them accessible to different stakeholders. For example the research will produce a policy brief jointly with ODI, develop easily understood maps, and hold workshops and webinars as well as publish a high impact paper and accompanying dataset.

Policy makers, such as DFID, World Bank, Gates Foundation, individual water ministries should benefit from this research by having a first estimate of groundwater recharge for different parts of Africa and information on the potential significance of crossing critical thresholds.

Practitioners (e.g. UNICEF, WaterAid, country water departments, water engineers and hydrogeologists) will benefit from the research by having a first estimate of potential recharge, and a methodology for how to assess recharge for their project areas. Also by examining critical thresholds and future climate scenarios it will allow practitioners to assess potential longterm vulnerabilities in water supply services.

3. Capacity Building and learing opportunities. The project provides a significant opportunity to build capacity in the African groundwater research community. The four African researchers rarely, if ever get the opportunity to meet or work together, and this research gives the platform for this to occur. It will also foster links between the French and English speaking African research communities and build bridges between US and UK researchers.

Publications

10 25 50
 
Description We have examined all the known field studies of groundwater recharge across Africa to establish how groundwater recharge relates to long term annual rainfall. We have confirmed a broad direct relationship between long term rainfall and recharge. Long term average annual recharge is rarely more than 10 mm where annual rainfall is less than 250 mm, or less than 10 mm when rainfall is greater than 500 mm. Much of the variability observed between sites of similar rainfall can be attributed to variability in annual rainfall and land use.
Exploitation Route This research is being advanced to look particularly at the role of intense rainfall events in contributing to groundwater recharge in semi arid areas.
Sectors Agriculture, Food and Drink,Environment

 
Description The findings have been drawn together with other information to provide policy briefs on how groundwater recharge may be influence by climate change and how this may impact future water supply. The database developed is also being used by NERC funded PhD students to develop recharge typologies.
First Year Of Impact 2016
Sector Agriculture, Food and Drink,Environment
Impact Types Policy & public services

 
Description Citiation in IPCC report Chaper 3 Freshwater
Geographic Reach Multiple continents/international 
Policy Influence Type Citation in other policy documents
 
Description Co author of policy brief on groundwater and global change
Geographic Reach Multiple continents/international 
Policy Influence Type Implementation circular/rapid advice/letter to e.g. Ministry of Health
URL https://iah.org/knowledge/learning-resources
 
Description Scottish HydroNation advisory committee
Geographic Reach National 
Policy Influence Type Participation in a advisory committee
Impact Participation in the HydroNation has led to the delivery of up to 12 additional PhD studentships per year in Scottish universities related to water.
URL http://www.gov.scot/Topics/Business-Industry/waterindustryscot/ScotlandtheHydroNation
 
Description Geoscience for Sustainable Futures
Amount £5,891,200 (GBP)
Funding ID NE/R000069/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 06/2017 
End 06/2020
 
Description UPgro Consortium grant
Amount £1,900,000 (GBP)
Funding ID NE/M008932/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 05/2015 
End 04/2019
 
Title African Groundwater Recharge database 
Description This is a database of 200 pre-existing published and grey literature studies of groundwater recharge. Delivered in an access database, the collection contains recharge data along with any meta data from the studies 
Type Of Material Database/Collection of data 
Year Produced 2014 
Provided To Others? Yes  
Impact The database will form the basis of a major publication in 2015. 
 
Description The Chronicles Consortium 
Organisation Africa Groundwater Network
Country South Africa 
Sector Charity/Non Profit 
PI Contribution Two investigators from this research, Richard Taylor from UCL and Alan MacDonald from BGS, have help to start this new consortium to collate and analyse multi-decadal groundwater-level observations for Africa
Collaborator Contribution Our partners from the research as also forming part of the this consortium, and were present at the in augural meeting in Marrakech, Morocco,
Impact This consortium has just started, therefore no major outputs yet,
Start Year 2014
 
Description The Chronicles Consortium 
Organisation Institute of Development Research (IRD)
Country France 
Sector Public 
PI Contribution Two investigators from this research, Richard Taylor from UCL and Alan MacDonald from BGS, have help to start this new consortium to collate and analyse multi-decadal groundwater-level observations for Africa
Collaborator Contribution Our partners from the research as also forming part of the this consortium, and were present at the in augural meeting in Marrakech, Morocco,
Impact This consortium has just started, therefore no major outputs yet,
Start Year 2014
 
Description The Chronicles Consortium 
Organisation International Association of Hydrogeologists (IAH)
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Two investigators from this research, Richard Taylor from UCL and Alan MacDonald from BGS, have help to start this new consortium to collate and analyse multi-decadal groundwater-level observations for Africa
Collaborator Contribution Our partners from the research as also forming part of the this consortium, and were present at the in augural meeting in Marrakech, Morocco,
Impact This consortium has just started, therefore no major outputs yet,
Start Year 2014
 
Description The Chronicles Consortium 
Organisation United Nations Educational, Scientific and Cultural Organization
Country Global 
Sector Public 
PI Contribution Two investigators from this research, Richard Taylor from UCL and Alan MacDonald from BGS, have help to start this new consortium to collate and analyse multi-decadal groundwater-level observations for Africa
Collaborator Contribution Our partners from the research as also forming part of the this consortium, and were present at the in augural meeting in Marrakech, Morocco,
Impact This consortium has just started, therefore no major outputs yet,
Start Year 2014
 
Description African Groundwater Webinar 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The webinar stimulated discussion and questions from the attendees

Some email activity after the webinar to be kept in touch of the results of the work
Year(s) Of Engagement Activity 2014
URL http://upgro.org/webinars-and-films/
 
Description BGS edinburgh Open day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? Yes
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Many interesting discussions about how people in developing countries have to fetch their water, and also the usefulness of groundwater as a source of safe drinking water.

Nothing directly as yet, however this is a regular activity, and we get request form young folk to carry out work experience etc as a results of coming to our open days.
Year(s) Of Engagement Activity 2014
 
Description British Science Festival 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact The talk and ensuing social media was followed by discussions from the public.

One participant[ant followed up to ask for information and guidance on how to find safe water for a charity she was involved in running.
Year(s) Of Engagement Activity 2014
 
Description Talk at an irrigation conference from the Institution of Civil Engineers 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Much discussion after the talk about the nature of African groundwater, how it could be used to increase irrigation across the region and how sustainable it would be.

Arranged for follow up meetings including one with a DFID advisor.
Year(s) Of Engagement Activity 2014