1. Program Hydrogeologist, Baseflow, Malawi
A review of climate change impact understanding on ground water
recharge and baseflow in the SADC region.
Steve Kumwenda,
Program Hydrogeologist, Baseflow, Malawi

2. A review of climate change impact understanding on ground water recharge and baseflow in the SADC region. Steve Kumwenda, Program Hydrogeologist, Baseflow, Malawi Preliminary sharing
Presentation Outline
Background introduction
Objectives and methodology
Review Rationale
Findings and Discussion
Conclusions
Recommendations

3. 2.5% freshwater, 0.3% renewable
Introduction
Ground water covers over 95 % of the world’s available freshwater. (Howard, et al., 2009).
75 % of safe sources of drinking water in the SSA are from ground water (Foster, 2006).
However, not easy to observe Climate Change impacts on ground water –Indirect and take long to observe
This affects understanding and policy
2.5% freshwater, 0.3% renewable

4. Introduction ctd..
Interaction between climate change and ground water is not well understood (UN, 2011) - Inadequate research
Mostly hypothetical analyses on the topic (IPCC, 2001).
Aquifers are recharged by effective rainfall,
An alteration in effective rainfall will affect ground water recharge
E.g. In Tanzania, decrease by 15% of rainfall - led to a decrease of groundwater recharge by 40 to 50% (Sandstrom, 1995)
A 20% reduction in average annual rainfall in central parts of Southern Africa - 80% decrease in recharge (Cave, et al., )

5. Objectives and Methodology
To bring to light the current literature understanding of climate change impact on ground water in the SADC region.
Add value to researchers in ground water and climate change impact interaction
Methodology
Systematic reviewing of published and grey literature
search engines such as google (scholar), Microsoft edge ,
Strathclyde University libraries.
The key words used in searching were ground-water, climate change impact, and Sub Saharan Africa,
Literature time frame - from 1995 to 2018.

6. Rationale
Ground water - alternative relief source (Portmann, et al., 2013)
Due to impacts on surface water - vulnerable water resource
E.g. In central Malawi over 250,000
affected
Most feared impact - alteration of the hydrological system (Gleick, 2000)
African countries - more prone to suffer, (IPCC, 2001)
Inadequate institutional capacity
slowed economic development- Climate Change, Not a priority

7. Rationale ctd.. Why do we seemingly have “infinite” groundwater?
Africa has warmed by 0.7 ℃ while rainfalls have decreased by 5 to 15 % over the 20th century
A further temperature rise projection of 1.5 ℃ by 2050 has also been indicated.
Why do we seemingly have “infinite” groundwater?
The world’s sedimentary aquifers- recharged some thousand years ago
e.g., the Southern Africa Kalahari sands, North Africa Nubian Sandstone aquifers (R.G. Taylor, 2013)
Such regional aquifer basins are storage dominated rather than recharge flux dominated (Foster, 2006)
And therefore non-renewable
Major impact –ground water over-abstraction vs surface water

8. Review Rationale ctd..
Climate Change Impact - ground water storage through changes in recharge. (Green et al, 2011). (Crosbie, et al., 2013)
Therefore, an understanding of the future recharge rates is required
UNESCO indicates relatively lack of research studies addressing the impacts of climate change on ground water. (IPCC, 2007)
Research has greatly focused on surface water
A few ground water models have been developed on ground water Climate Change impact (Cooper, et al., 1995)
A lot of impacts currently are un predictable and remain speculative

9. Findings and Discussion
Ground water is less responsive to short term climatic variability compared to surface water. (Bonsor, et al., 2010)
Relationship between rainfall intensity and ground water recharge - not outright direct
Recharge patterns - affected by soil degradation and vegetation changes
The BGS undertook a study on Ground Water resilience to climate change Across Africa. (MacDonald, et al., 2011)
Ground water maps for Africa
However, Regional level focus- National application needed

10. Findings and Discussion ctd..
Groundwater aquifer maps for Africa
Estimated groundwater storage for Africa (left) and aquifer productivity map across Africa(right) Source: MacDonald et al. 2012; British Geological Survey NERC 2011, Used with permission

11. Findings and Discussion
Why slow breakthroughs?
The BGS notes hydrogeological data is missing
hydraulic conductivity, transmissivity, Storativity/storage are rarely available.
Most basic available data on hydrogeology is from geology, borehole depth and borehole yield.
Before 2007 ground water research studies were rare
Currentlty studies are mushrooming (Jiménez, et al., 2014)
4 to 20 Global Models on impact of Climate change on Ground Water
However, regionally and nationally there still challenges

12. Findings and Discussion ctd..
UNESCO notes hydrogeology – relatively young discipline (Foster, et al., 2006).
Only in recent years that ground water experts began to understand the groundwater climate change interactions
Other studies coming up that will enhance understanding of ground water first
E.g. 
BGS - Africa regional aquifer storage atlas,
Malawi also has a project on CGS atlas of aquifers
University of Strathclyde works on transboundary aquifer and Shire river basin conjunctive use with SADC GMI

13. Conclusion The most feared impacts of climate change Limitations
Alteration of the hydrological cycle- ground water recharge
Though the link between rainfall and aquifer recharge- Not outright direct (Bonsor, et al., 2010)
Ground water storage depletion as an alternative source to drought impacted surface water
Limitations
Not exhaustive – but a current understanding regarding the topic.
The paper is still being worked on – for publication

14. Recommendations
Water sector development agencies and Governments in the SSA
National level mapping of ground water aquifers, basins
This conference - substantial research is being generated
Support ground water data collection on aquifer properties/ characteristics
Ensure Adequate skilled technical personnel to engage in such ground water data MIS.
Need for more Ground water flow modelling trained professionals.
Enhance the already regional joint research and monitoring programs
Regulation of ground water use - over abstraction
Need for renewed understanding of ground water recharge dynamics in relation to the current and expected climate change. (Burney, et al., 2013)

15. Recommendations ctd..
Scale up of the Hydrogeology as an academic discipline,
Undergraduate and Post
Continuous Professional Development.
This is one key area that the SADC GMI is collaborating
-University of the Free State,
-UNESCO IHP
-University of Strathclyde

16. (care for the water upon which you depend)
Thank You.
…Into the well from which you drink do not throw stones...Arabic proverb
(care for the water upon which you depend)