Sunday 29 July 2012

Substantial new aquifer found under northern Namibia.

Scientists from the German Federal Institute for Geosciences and Natural Resources, working in northern Namibia have this month announced the discovery of a substantial new aquifer, named Ohangwena II. The reservoir covers an area of roughly 40 by 70 km at a depth of 280-350 m beneath ground level in Namibia, and also to extends under southern Angola. It is thought to contain enough water to supply the 800 000 people of northern Namibia for 400 years at current consumption rates, although water consumption rates tend to go up when abundant fresh water becomes available. 

Namibia is generally considered to be the driest country in Sub-Saharan Africa, though fortunately it is not among the poorest. It has a population of 2.4 million, and a population growth rate of 1.8% per annum, low for Sub-Saharan Africa, but still twice that of the US or nearly three times that of the US. Much of the north of the country gets its water from an aging canal network brining water south from Angola. As such Namibia is in need of new and reliable sources of water.

Geologist Martin Quinger, who led the project that discovered the new aquifer, believes that it cane be managed in a sustainable way, with water being drawn off only at a rate which matches the replenishment rate for the aquifer, which is fed by rainfall in southern Angola. However he cautions that the resource must be managed carefully, as it is overlain by a shallower, saline aquifer, Ohangwena I, and inexpertly carried out drilling could potentially contaminate the lower water source.

Simplified diagram showing the positions of the Ohangwena I & II aquifers. Planet Erde.

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