Ethiopia is a landlocked sub-Saharan nation, covering 1 million km2 in east Africa. Its unique geography presents an interesting case study for exploring the impact of climate change on groundwater and the need for its effective management. On the whole, Ethiopia has naturally abundant water sources. However, it faces water-stress due to unpredictable weather patterns and poor investment in water-infrastructure.
Putting it in context
Groundwater accounts for around 96% of the world’s unfrozen freshwater, making it a critically important asset to appropriately manage and a resource that cannot be ignored in the face of climate change. The impact of climate change on groundwater storage is a topic of recent scientific interest, but has historically been a challenge to study and predict. This challenge has been accentuated by ever-changing human modification of land and over-exploitation of ground water sources. The climate system is incredibly complex, with webs of interactions that produce spatially and temporally varied weather patterns. Climate change has both direct and indirect impacts on groundwater systems. On the one hand, it directly impacts groundwater recharge and ground-surface water interactions. On the other hand, groundwater is also indirectly affected by land-cover/use change and consumption. Whilst higher temperatures drive increased evaporation and evapotranspiration, which risk drying up water storage, more extreme rainfall events offer opportunities for groundwater recharge. Although surface water will no doubt become increasingly unreliable with a changing climate, groundwater is thought to be relatively resilient and thus a great asset in climate change mitigation.
Groundwater has been Ethiopia’s dominant water resource since the 1970s, largely due to the high cost and unpredictability of surface-water based schemes. In fact, groundwater provides nearly 90% of the country’s freshwater supply for domestic and industrial use. Yet, Ethiopia has been historically vulnerable to severe drought, multiple episodes of which have incurred substantial social and economic costs over the past 50 years. Throughout the 21st century, Ethiopia has seen rapid development and subsequent population expansion, including major patterns of rural-urban migration. This (particularly urban) population expansion is putting strain on existing water infrastructure, making groundwater a focal point for research into cost-effective water supply.
Water-security is a technological issue
Access to water is spatially uneven across Ethiopia. The impact of droughts is most readily felt in areas with poor water-infrastructure, principally in rural communities. Water-security is largely determined by the distribution of technology. Traditionally, groundwater has been accessed via hand-dug wells and springs across most of sub-Saharan Africa. These methods are often inefficient and ineffective; depleting quickly with slow recovery. Comparatively, shallow boreholes, equipped with hand pumps, have been found to be a far more reliable means of coping with periods of drought, as demonstrated through the 2015/16 El Niño event. During this period, communities reliant on springs and hand-dug wells were most severely impacted by the drought. Slow recharge and inefficient collection methods led to long collection times, physical conflict and missed school time, whilst higher levels of bacterial contamination resulted in significant health impacts. Borehole drilling is the most effective method of increasing local water-security, thus developing borehole and hand pump technology can improve drought resilience. Focussing on the implementation and maintenance of borehole access is a key towards promoting water-security, particularly in arid and semi-arid rural regions, where surface water is unpredictable.
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| A community in Ethiopia accessing groundwater from a borehole via a hand pump |
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| An unprotected hand-dug well |
Groundwater recharge is spatially and temporally varied across Ethiopia, ranging from 0 to 300mm a year. Although it is difficult to predict the impact of climate change on Ethiopia’s groundwater, it has been suggested that an increasing number of extreme rainfall events will help increase recharge. Combined with groundwater’s supposed natural resilience, this makes it an important focus for research, development and effective management. Current infrastructure limits accessible groundwater to just 2.6 billion cubic meters. However, the groundwater storage potential of Ethiopia is estimated to be as high as 40 billion cubic meters, making it a significant resource to be tapped into. The Ethiopian government now has plans to develop several pioneering groundwater-fed irrigation projects, that will be a regional first. The potential success of these plans could inspire other sub-Saharan nations to focus on the utilisation of groundwater, without disregarding the need for effective management.
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