Groundwater-a plausible solution? (Part 2)

Expanding on last week’s topic of the potential of groundwater as a reliable water source in Africa with population growth and an increased demand for irrigation water for agriculture. The first part of today’s post is based on an article ‘Groundwater in hard rocks of Benin:Regional Storage and Buffer Capacity in the face of change’ (Vouillamoz et al. 2015).

Like the article by Taylor et al. (2009), groundwater is said to play a major role in supplying domestic water to millions of people in Africa, and is likely to be increasingly dependent on to increase reliable water sources for domestic and irrigation purposes. The paper was based on research that sought to estimate the capacity of hard rock aquifers to buffer changes in climate and anthropogenic conditions in Benin, by comparing groundwater storage to the total discharge of the reservoirs. The research found that current groundwater storage represents about six years of total groundwater discharge—the first time the buffering capacity of groundwater storage against changes in water balance was quantified at the regional level. Climate and land use changes will most likely impact evapotranspiration and in turn groundwater storage, perhaps more than population growth will.

Some thoughts and reflections:

• The availability(?) of groundwater resources is heavily dependent on the geology, as well as the climate of the area
• Though such hard rocks is said to cover 40% of the surface area in Africa, which means substantial potential for groundwater storage
• Access needs to be considered in harnessing the groundwater for use, as well as maintaining the quality of the groundwater, and distributing it equitably

Another article: ‘What impact will climate change have on ruralgroundwater supplies in Africa?’ (MacDonald et al. 2009) supplements that last reflection point. 

The article explains that the preparing and coping with climate change will generally call for actions already identified for improving water security for communities—of which understanding the balance between water availability, access and use/demand is key. For example, there would be a need for research to match the availability of the water in groundwater storage with local demand and needs by siting sources in the most productive parts of the aquifer. 

One other way in which groundwater can be relied upon with climate change and the related changes to the hydrological system is the development of water further for small-scale irrigation. It is imperative however, for development to be done in a sustainable manner to avoid groundwater depletion caused by abstraction beyond domestic use.

Some thoughts and reflections: 

Whether or not groundwater can serve as a sustainable, viable source with climate change and population growth is dependent on many factors other than the availability of groundwater supplies:

• Enabling ease of access to groundwater supplies in a way that is productive and efficient
• Regulating abstraction for domestic use and possibly irrigation to prevent depletion of supplies
• Maintaining the quality of groundwater, by sealing the wells or constructing cement barriers around them to prevent the washing of pathogens into them
• Greater availability of data on groundwater storage and the links between climate change and groundwater to guide policy decisions and water infrastructural development

One area that may be explored in the coming weeks is the effect of climate change on human behaviour and how this may affect the use of water and the hydrogeological system in Africa. 

Benin Groundwater Resources Program
Source: https://ndigd.nd.edu/notre-dame-projects/topics/infrastructure/#benin-groundwater-resources-program