resources. The most water-poor regions of the Middle East and North Africa contain only 0.5 per cent of freshwater reserves and as home to 5 per cent of the globe’s population, have the lowest available water reserves per person in the world. Such an uneven distribution of water resources means that inevitably some countries experience either physical or economic water shortages, while in others there is no scarcity at all, as Figure 4.18 shows.
Water scarcity extreme physical water shortage physical or approaching physical water shortage economic water shortage little or no water scarcity no data
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A physical water shortage occurs in a country when all available reserves have been exploited and demand continues to rise. An economic water shortage means that people have insufficient water even though there are adequate water reserves available. This is often the case in the world’s lowest income countries, which commonly do not possess the capital or technology to invest in fully exploiting their water reserves. This is true in many Sub-Saharan countries of Africa. Angola is ranked by the World Bank as 116th in terms of wealth out of 183 countries and Angolans have an average life expectancy of just 50 years. Despite having potential water reserves of over 6000 cubic metres per person, less than 10 per cent has so far been exploited. Because water is the world’s most valuable natural resource, serious disagreements and even conflicts can occur between countries when its ownership and use is disputed. When in 2013 Ethiopia began construction of the Renaissance Dam project on the Blue Nile, ∆ Fig. 4.19 Cachoeiras waterfall, Angola. one of the major tributaries of the River Nile, the government of Egypt threatened to declare war. The River Nile (Figure 4.20) is fed by waters from 11 countries, and 40 million
WATER QUALITY AND AVAILABILITY
∆ Fig. 4.18 Water scarcity by country.