Is Groundwater a solution?

So over the past few blog posts, we have figured out that Africa actually has enough water to sustain its population, but the problem lies much deeper. Its the uncertainty and high variability, both spatially and temporarily that's creating water stress in Africa.

I think a possible solution is to develop the use of groundwater to foster agricultural production and feed the hungry people. Is this a reasonable approach? We shall find out in the next couple of weeks :)

For this post I will be looking at an article by Giordano 2006, which provides an assessment of groundwater resources for agriculture on the continent.

National estimates of the FAO suggests that African groundwater supplies can be replaced at a rate of 1,500 cubic km /year (FAO 2003). This is much greater than the water availability in countries such as India and China, which have seen a green revolution driven by groundwater. So at a first glance, there is nothing stopping Africa from doing the same.

Data suggests that at present, there are over 1 million hectares being irrigated by groundwater, with 1% of the African population directly depending on it for agricultural production (FAO 1986). In many arid parts of Africa, groundwater plays a vital role in sustaining livestock, forming a basis for human survival. In some countries like Somalia, the groundwater resources are used entirely for livestock and none for crops (Githumbi, in press). With over 10% and 65% depending on livestock directly/indirectly respectively, and given that livestock heavily depends on groundwater, the role and of groundwater as a resource substantial. It is also possible that the contribution of groundwater to livestock is much higher than for crop agriculture.

However much like other water resources, groundwater is highly variable and its quantity depends on a number of factors.

•  Geology: the type of rock determines its capacity to store water, so for example consolidated rock types and volcanic rocks are able to produce high groundwater flow, compared to other types.
• Climatic conditions: hydrological function and distribution of groundwater is connected to rainfall patterns.
• Fossil ground water reserves. 

So although on one hand Africa has plenty of groundwater available, due to geology, the water is located deep under ground and in areas which are problematic to access, thus increasing the cost of exploitation. Moreover, groundwater supplies tend to be located in areas with high rainfall in the first place, thus undermining the whole point of having them. Groundwater currently is concentrated in just 4 countries, creating problems for access and distribution.

Although groundwater is currently used to an extent for farming, particularly in livestock, there are some barriers to fully maximise its development and role in agriculture. These problems should be addressed in the near future, if we are to solve the issue of water in Africa. Moreover I would agree with Giordano in the sense that more research and quantification of groundwater resources is needed, particularly if we want to create a solution. We are in need of actual data on the current usage and contribution of groundwater to agricultural output. This would enable to plan and provide an adequate program for future development of this valuable resource.

Yes there are limitations to groundwater, but on the whole, I would imagine that currently it is one of the possible solutions to water shortages in Africa and to expand crop irrigation.

In my blog posts further I hope to expand the theme of groundwater by looking at its current use in agriculture, what groundwater supply depends on, its future opportunities and whether it is sustainable.


Until next time :)