Rising groundwater could combat climate crisis in drought-stricken areas

New research suggests better groundwater supply management could be key to helping drought-stricken areas to cope with the climate crisis.  

The study, led by the University of Bristol, examined changes in rainfall in East Africa, which frequently suffers from drought and water and food scarcity, over the past 30 years.  

Results showed total rainfall during the main rainy season, named the ‘long rains’, is declining across the Horn of Africa Drylands, but rising in the shorter rainy season, the ‘short rains.’  

This trend applies to Ethiopia, Somaliland, Somalia and Kenya, leading researchers to investigate how this has impacted below groundwater storage, a potential lifeline during drought periods.  

They found water storage has been increasing in recent decades, despite the declining ‘long rain’ seasons which historically deliver more rain. 

Lead author Dr Markus Adloff, who conducted the study as a researcher in the School of Geographical Sciences at Bristol, said: ‘This was surprisingly paradoxical, but also hugely significant as it points to a possible silver lining that may support climate adaptation. Our findings suggest groundwater may have the potential to support increasingly food and water insecure rural populations in the Horn of Africa drylands.’ 

By analysing rainfall data and studying the characteristics of rainfall over this time, the team discovered heavy rainfall is becoming more common in the ‘short rains’ season.  

Drylands see low annual rainfall and evaporate quickly, so if rain is light and drizzly it will evaporate rapidly, as it is held in the shallow parts of soil. But if it is intense and heavy, it produces runoff which can infiltrate the soil and avoid evaporation.  

The results offer hope to the Horn of Africa, which is experiencing its fifth consecutive season of below-average rainfall, with 50 million people facing famine, water shortages, livestock deaths, and failed crop harvests.  

Depth and quality of the available groundwater is currently unknown and whether discovered trends would continue if more failed rainy seasons were to come needs to be studied.  

Dr Michaelides added: ‘These unanswered questions highlight the necessity for extensive groundwater surveys across the Horn of Africa region. This is vital to assess whether this apparently increasing water resource may be economically viable enough to help offset the catastrophic impact of unprecedented recurrent droughts, which tragically look set to continue as climate change worsens.’ 

A report on ecological threats has found more than 750 million people are suffering from food insecurity, an increase of 35% since 2017, due to the climate crisis, the war in Ukraine and inflation. 

Photo by Matt Palmer