Africa – Groundwater Pollution Risks

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New report suggests that the danger of groundwater supplies in Africa becoming polluted is significant.

According to a recent report, cited by UK-based the Guardian, much of Africa’s groundwater, particularly in populated areas, lies close to the surface and is vulnerable to pollution.

Using a map to plot data the report shows that much of the coastal areas around the Gulf of Guinea and much of Central Africa are at serious risk, whereas the Sahara Desert, where the water is much deeper underground, is least at risk from pollution.

The researchers found that groundwater supplies are mainly at risk in agricultural basins, areas which often contain high levels of nitrates and pesticides; evidence of nitrates in groundwater were a key parameter for the research.

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http://www.sciencedirect.com/science/article/pii/S0048969715311189

Alan McDonald, a hydrologist with the British Geological Survey recognised the difficulty of the project due to the interlinked nature of many parameters, but that it was important to provide a comparison across the continent and to identify those areas most at risk.

Further developments will seek to integrate soil data with the African groundwater map, to show the interlinkages and dynamics between groundwater pollution and soil health. Particularly important are fractured crystalline rocks which occur across a third of the African continent and allow water to sink into underground aquifers, possibly allowing for increased pollution.

A separate report released a few days later on January 14th said that groundwater supplies are crucial for crops but that increased agricultural expansion is making droughts and water shortages worse, reported Chinese news agency Xinhua.

“We wanted to understand what happens to rainfall, runoff and groundwater levels when you transform a savannah into agricultural land, something that’s happening more frequently as West Africa tries to produce more food” said researcher Marc Parlange, Professor of Civil Engineering at the University of British Columbia, Canada.

Over a period of three years the project recorded rainfall, temperature, humidity and soil characteristics at a natural savannah forest in Tambarga village in southeastern Burkina Faso, and at a rice and millet field in an agricultural area. The study showed that the savannah forest received around 15% more rainfall than the agricultural setting.

“This study highlights how changing one part of the ecosystem could have an unforeseen effect on other parts. It raises questions about how our ecosystems should be managed for future generations and for the native plant and animal species as well,” said Parlange.

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Earlier in 2015 scientists, writing in the journal ‘Environmental Research Letters‘, claimed that vast aquifers sit underneath the African continent, such that many countries declared as water scarce may have substantial groundwater reserves.

However, the scientists are cautious about the best way of accessing these resources. With many aquifers not being filled due to a lack of rain, the scientists are worried that they could be rapidly depleted by large-scale developments, reported BBC News.

A study by the Global Freshwater Initiative found that 45% of major cities solely dependent on surface water will be unable to simultaneously meet human, environmental and agricultural water demands by 2040, reported Phys News.

Groundwater reserves remain crucial to the water supplies and agricultural production across the African continent, and as recent research has highlighted there is a need for the careful management and a heightened awareness of the dangers of pollution, in these groundwater reserves.

Find out more in the Africa Research Bulletin today

AFRICA: Securing The Future
Economic, Financial & Technical Series
Vol.52, No.4, Pp.20805A–20806A

Water Projects
Economic, Financial & Technical Series
Vol.52, No.1, Pp.20724A–20724C

WATER: Africa
Economic, Financial & Technical Series
Vol.49, No.12, Pp.19823B–19825C

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