Researchers have found vast groundwater reserves in the Sahara, one of the driest places on earth, that could help buffer climate change effects for years.

Researchers from the British Geological Survey and University College London, who have prepared a map of the aquifers or groundwater in Africa, say the volume of water found beneath the driest parts of the continent is around 0.66 million cubic kilometres — 100 times the volume found on the surface.

The largest groundwater volumes are found in the large sedimentary aquifers in the North African countries of Libya, Algeria, Egypt and Sudan,” said a scientist associated with the research, the journal Environmental Research Letters reports.

The research, however, points out that not all these reserves — some of which are as deep as 100-250 metres — can be accessed, according to the Daily Mail.

Small-scale extraction using hand pumps would be better than large-scale drilling, which could quickly deplete the reservoirs and may have other unforeseen consequences, said Stephen Foster, London-based senior adviser for aid group Global Water Partnership.

“It is not as simple as drilling big bore holes and seeing rice fields spring up everywhere,” said Foster, an expert on groundwater issues.