Africa lies on a huge underground water tank

British scientists say that the dry continent of Africa lies on a giant groundwater tank, with a volume of over 100 times the surface water.

However, extensive well-drilling techniques are probably not the best way to exploit water, the study reported in the journal Environmental Research Letters .

Across Africa, more than 300 million people do not have access to safe drinking water. Water demand is expected to increase significantly in the coming decades due to population growth and crop cultivation.

Freshwater rivers and lakes often experience seasonal floods and droughts, limiting the ability of people to provide water and crops. Only 5% of cultivable land is irrigated.

Now, for the first time, scientists at the British Geological Survey (BGS) and the University of London can perform a groundwater analysis across the continent and draw a detailed map.

Africa has more water than we often think. (Source: BBC)

Helen Bonsor, a BGS scientist, said that the water maps will expand people's vision of water potential in Africa.

Due to climate change, the Sahara has become a desert many centuries ago, many groundwater aquifers were maintained 5,000 years ago.

The scientists examined and compared information from water and geological maps and 283 aquifers. They say new maps show that many countries that are considered 'rare' countries now have significant groundwater reserves.

Scientists say that the amount of groundwater is enough for people to deal with the doldrums of climate change. Even in the semi-arid regions, where there is little rainfall, aquifers can still provide water for 20-70 years.

However, scientists believe that it should not be drilled well to exploit groundwater, but need to calculate to drill in the appropriate location, using hand pumps to exploit slowly.

Because many aquifers are not supplied with more water due to lack of rain, scientists fear that extensive well drilling can quickly drain groundwater.