Water gives life and is crucial to development all over the world. It waters the fields; nurtures the crops and stock; provides recreation; it supports mines, industry; electricity generation and it provide life for plants and animals that make up ecosystems. According to the Intergovernmental Panel on Climate Change (IPCC), climate change would be one of the key challenges of mankind in the next decades. Key findings of their 2007 report include:
- 75-250 million people across Africa could face water shortages by 2020;
- More heavy rain events are very likely, and more areas are likely to be hit by drought;
- Crop yields could increase by 20% in East and Southeast Asia, but decrease by up to 30% in Central and South Asia;
- Agriculture fed by rainfall could drop by 50% in some African countries by 2020;
- 20-30% of all plant and animal species would be at increased risk of extinction if temperatures rise between 1.5-2.5˚C;
- Glaciers and snow cover are expected to decline, reducing water availability in countries supplied by melt water.
The global water availability per capita can be seen in Figure 1. It can be noted that Africa is the one continent that will face big water shortages and it is predicted that at least 9 countries in Africa will have less than 500 000 litres per person per year available.
Although it sounds a lot of water, one need to understand how much water is needed to produce food. In this regard, Virtual Water is the amount of water that is embedded in food or other products needed for its production. Virtual water refers to the amount of water required to produce a good from start to finish or it is the volume of freshwater used to produce the product, measured at the place where the product was produced. The following is interesting to know:
- It requires 13 litres of water to produce one tomato,
- It requires 25 litres of water to produce one potato,
- It requires 50 litres of water to produce one orange,
- It requires 70 litres of water to produce one apple,
- It requires 140 litres of water to produce one cup of coffee and
- It requires 2500 litres of water to produce one hamburger
The water footprint of people in different countries in litres per person per day are shown in Figure 3.
With the global average of 3 400 litre per person per day you need 1 241 000 litre per person per year which is more than double the amount that will be available in those 9 countries. In order to conserve water resources, close attention must be paid to the performance of irrigation systems and continued evaluation and maintenance of irrigation systems are imperative to keep the performance on a high level and to optimize water use efficiency.
Water, as the main input for food production, has played the most significant role in population growth and societal evolution over much of the recorded human history. It, as the key natural resource, is fundamental to all economic, social and environmental development processes. Thus, efficient water resources management is essential for achieving poverty reduction through inclusive growth; maintaining public health and food security; providing livelihoods for a life of dignity for all; and sustaining long-lasting harmony with the Earth’s essential ecosystems. Numerous civilizations flourished and then also became extinct because of the way they managed their agricultural water.The full article is for subscribed members only. To view the full article please subscribe. It’s FREE!Log In Register
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