Misconceptions

Even though most of us know that water is an integral part of food production, many of us are not aware of the relationship between water scarcity and food security. Why is water so fundamental? Before proceeding onto later blog posts, I would like to remove the many misconceptions about water and food that we may have.

Initially, before starting my geography degree at university, I would stare into the depths of the ocean whenever I visited the beach and I would ponder why countries could not access this water for drinking and why so many areas had water shortages. After all, our earth’s hydrosphere contains 1386 million cubic kilometres of water; it is the most widespread substance on our planet (Shiklomanov 1998).  Most importantly however, only 2.5% of this is freshwater and 97.5% is saline (ibid). To make matters worse, from the little freshwater available, 68.7% of it is locked up as ice in the Arctic and Antarctic regions (ibid). The distribution, state and salinity of the water are all factors shaping who has access to water.

Exponential population growth has been significant in shaping the demand for water throughout our world. As the world’s population grew between 1970 and 1994, it was estimated that the potential water available per person per year fell from 12.9 down to 7.6 thousand cubic metres (ibid). This statistic is all the more relevant for my blog’s focus on Africa, as the continent experienced the greatest reduction in population water supply throughout this time (ibid).

Water Scarcity

I hope the above information sheds some light onto the weight and relevance of the word ‘scarce’ when we are talking about water scarcity and why such an indicator is necessary. Water scarcity can be broadly defined as the ‘shortage in the availability of renewable freshwater relative to demand’ (Damkjaer and Taylor 2017: 513). However, there have been attempts at designing a more robust metric. The Water Stress Index (WSI) developed in the 1970s and 80s defined water scarcity as ‘the number of people that compete to be sustained by a single flow unit of water’ (ibid: 514). The Water Stress Index proposed by Falkenmark in 1989 evaluated the thresholds at which different levels of scarcity occurred (Brown and Matlock 2011). 

Table 1: The Water Stress Index (Brown and Matlock 2011).

Table 1 outlines these thresholds; a country which is only able to supply under 500m³ of water per person per year is said to be experiencing ‘absolute scarcity’. It has been a popular indicator and has been widely used because it is easy to calculate and interpret (Herath et. al. 2010; Gleick et al. 2002).

Figure 1: A map of water scarcity in Africa in 2014, using the Water Stress Index (Damkjaer and Taylor 2017). 

Let’s take a moment to observe Africa as a whole. Figure 1 highlights an interesting distribution of freshwater, whereby countries towards the north and south are experiencing greater water scarcity such as South Africa, Libya and Algeria. However, when compared to other indexes of water scarcity, whether this data is meaningful falls under question (Damkjaer and Taylor 2017). This is because the Water Stress Index proposed by Falkenmark has a number of major limitations; the values are skewed due to spatial and temporal factors.

Limitations:

• The values are national annual averages which means that unique data at regional levels on a smaller scale has been ignored (Brown and Matlock 2011).
• The annual average will ignore any seasonal variation which is significant due to the dry and wet seasons caused by the ITCZ in the area.
• The thresholds themselves are too simple as they ignore cultural and lifestyle differences, which will mean demand will vary from country to country (Rijsberman 2006).
• Leading from the above limitation, these thresholds are static and do not represent the changing dynamics and demands of the future, as our technology advances (Brown and Matlock 2011).
• Artificial water supplies from desalination plants are overlooked (Damkjaer and Taylor 2017).

An indicator which attempts to resolve these limitations, by taking artificial sources into consideration for example, is physical and economic water scarcity (Damkjaer and Taylor 2017). Adaptive capacity, a concept which will be explored in greater depth in my next blog post, is what determines whether a country is economically scare or physically scarce. There are many other metrics to be aware of, some of which are holistic:

• Social Water Stress Index
• Agricultural Water Poverty Index
• Basic Human Needs Index
• Water Poverty Index
• Watershed Sustainability Index
• Canadian Water Sustainability Index

We’ve talked about water scarcity at varying scales, but what can we do on a domestic scale to help reduce water scarcity? Continuing on with our discussion about misconceptions, this excellent short video produced by TED-Ed highlights the fact that domestic water use only counts for 8% of water consumption. So having shorter showers and turning off the tap whilst brushing your teeth is not enough to solve the global problem. 

Another widely held misconception is that most of our water is used for the purpose of drinking. In fact, as discussed in the video, agriculture is the biggest consumer of water which accounts for 70% of all withdrawals (FAO 2011). Even though a lack of access to clean drinking water is a major problem in Africa, on average a person is only required to drink 2-4 litres a day. This is compared to the 2,000 to 5,000 litres of water required to produce a person’s daily food intake (ibid).

This blog post is necessary in order to put my future blog posts into context. Hopefully I’ve given you much food for thought, no pun intended. 

List of references

Brown, A. and M. D. Matlock (2011) ‘A review of water scarcity indices and methodologies’, White paper, 106, 19.

Damkjaer, S. and R. G. Taylor (2017) ‘The measurement of water scarcity: defining a meaningful indicator’, Ambio, 46, 513-531.

FAO (2011) Water at a Glance: The relationship between water, agriculture, food security and poverty.

Gleick, P. H. Chalecki and A. Wong (2002) ‘Measuring Water Well Being: Water Indicators and Indices’, in P. H. Gleick, W. C. G. Burns, E. L. Chalecki, M. Cohen, K. K. Cushing, A. S. Mann, R. Reyes, G. H. Wolff and A. K. Wong (eds.), The world's water, 2002-2003: the biennial report on freshwater resources, London: Island Press, 87-112.

Herath, I. K., B. Clothier, and D. Horne (2010) Indices of the status of freshwater resources for impact analyses, in: Proceedings of the 19th World Congress of Soil Science, Soil Solutions for a Changing World, Brisbane, Australia, 1–6.

Rijsberman, F. R. (2006) ‘Water scarcity: Fact or Fiction?’, Agricultural Water Management, 80, 5-22.

Shiklomanov, I. A. (1998) World water resources. A new appraisal and assessment for the 21st century, Milton Keynes: UNESCO.