Resilience of rural groundwater supplies to change Prof Alan MacDonald + many others
Groundwater: a AAA reserve … Natural storage: large volume, widely distributed, generally good quality accounts for a third of global abstraction (800 - 1000 km3) Vital for adaptation to climate change
How resilient is groundwater to changes in climate and abstraction?
Resilience framework Short term OK - Long term unsustainable Aq Volume abstraction unsustainable Susceptible to drought Long term recharge abstraction Foster and MacDonald 2014
High storage, variable yields MacDonald et al. 2012
Some evidence from satellites: GRACE Monthly estimates of changes in water storage 5 mm resolution Large footprint (400 x 400 km Bonsor et al 2018
Groundwater storage 2002 - 2016
El Nino2015/16: SADC Kolusu, et al submitted
GRACE TWS and GWS anomalies Kolusu, et al submitted
GRACE and GWLs: Limpopo
GRACE and GWLs: Makutapora
Summary for large scale At the large scale and medium term - groundwater appears fairly resilient No evidence of large scale depletion GWS coupled to modern rainfall: interesting questions of recharge processes However – short term stresses
Using groundwater to reduce poverty Photo WG Burgess Prof Alan MacDonald
what is a functional water point? 74% 66% what is a functional water point? 55%
Why are so many failing? U P G R O
Deconstruct pump
Test the aquifer…
chemistry
Borehole construction
Detailed community discussions
Technology and water security in Ethiopia
Springs
Hand dug wells
Boreholes
Reticulated Services
Reticulated services Maurice et al 2018 Taylor et al 2013
Summary Resilience: storage, long term recharge, permeability, technology At large scale and medium time frame: evidence of resilience Village level – importance of siting in high permeability areas + O&M Higher yields – less resilient? Choosing appropriate technology and maintenance models
Recommendations Keep monitoring groundwater levels Measure functionality of water points Investigate how rural communities actually use water in drought Investigate recharge processes and links to land use, abstraction, geology, climate Choosing appropriate technology and maintenance models