5.8B - Importance of Water Supplies
The importance of water supply for economic development (industry, energy supply, agriculture) and human well-being (sanitation, health and food preparation); the environmental and economic problems resulting from inadequate water.
Economic development is one of the main drivers of the increasing demand for water.
Agriculture
Agriculture dominates water use; about 3,770 kilometres of water are withdrawn each year, more than twice the total withdrawn for industrial and domestic purposes. Around 20% of the world's land is under full irrigation. About 30% of this irrigation comes from dams and their network of irrigation canals. But the majority of irrigation water is pumped directly from aquifers and is leading to massive groundwater depletion, especially in China, India, Pakistan and the USA. Clearly, the water situation is unsustainable and hydrological cycles are being seriously disrupted.
Industry and energy
Just over 20% of all freshwater withdrawals worldwide are for industrial and energy production. Industries such as chemicals, electronics, paper, petroleum and steel are major consumers of water. Water pollution is a major problem associated with much of this industrial use of water.
Over half of the water used by energy production is either for generating HEP or as cooling water in thermal and nuclear power stations. So all this water is returned to its source virtually unchanged. However, there is mounting concern about the growth of biofuels for the production of bioethanol and biodiesel, since these crops are very thirsty.
Over half of the water used by energy production is either for generating HEP or as cooling water in thermal and nuclear power stations. So all this water is returned to its source virtually unchanged. However, there is mounting concern about the growth of biofuels for the production of bioethanol and biodiesel, since these crops are very thirsty.
Domestic Use
So With economic development comes rising standards of living and an increasing per capita consumption of water. Safe water is a fundamental human need. However, water does have its risks so far as human well-being is concerned. Water, particularly that polluted by lack of sanitation, is an effective medium for the breeding and transmission of a range of lethal diseases, such as typhoid, cholera and dysentery.
Water is also a productive breeding ground for some disease vectors, such as mosquitoes, snails and parasitic worms. Malaria, dengue and bilharzia are dehabilitating vector diseases. So safe water is vital to human health, particularly in the context of washing and food preparation.
From the above, it can be seen that an inadequate supply of water can easily impede any water-dependent aspects of economic development. Costs may well rise.
An inadequate water supply will also threaten human health. Environmentally, it will encourage people to over-exploit what water resources there are. This could easily prolong periods of drought and possibly be a first step on the downward path to desertification.
Water is also a productive breeding ground for some disease vectors, such as mosquitoes, snails and parasitic worms. Malaria, dengue and bilharzia are dehabilitating vector diseases. So safe water is vital to human health, particularly in the context of washing and food preparation.
From the above, it can be seen that an inadequate supply of water can easily impede any water-dependent aspects of economic development. Costs may well rise.
An inadequate water supply will also threaten human health. Environmentally, it will encourage people to over-exploit what water resources there are. This could easily prolong periods of drought and possibly be a first step on the downward path to desertification.