First 472 words of the document:
Demand for water
Factors that cause the demand for water to change
Change in population size -
The population may grow because the birth rate is higher than the death rate or because
of immigration. Migrants may move from other countries or within a country.
Change in living standards -
In the poorest communities were there is no piped supply, domestic water may be
limited to the amount that can be carried from the source, which may be the nearest
river. As piped water becomes available and people become increasingly affluent, they
buy more appliances that use water such as washing machines and dishwashers or
luxury recreational items such as swimming pools and spa baths. Although modern
appliances may be designed to use less water, there is still a link between affluence and
Different industries have different water requirements. For example, irrigation use
uses more water than all other human uses combined. Subsistence agriculture usually
relies on the water that is naturally available, adapting the type of farming if water is a
problem, for example normadic herding rather than arable farming. As affluence
increases and energy and equipment become available, irrigation can increase, pumping
water from aquifers and rivers or storing in it a reservoir.
Heavy industries such as the chemical and steel industries or paper making use much
more water than lighter manufacturing industries. Service industries such as finance,
insurance and education use very little water apart from the water used by the
workers for domestic needs.
Changes in attitude to water use -
In some countries such as Australia problems with water supplies have encouraged
people to be more imaginative about how they collect water and much more careful
about how they use it.
Global water supplies
The availability of water, affluence and development are interconnected issues.
Countries or communities that are poor may not be able to afford to purify water so
water-borne diseases are common. Dry periods can kill crops, livestock and people. It
may also be difficult for them to exploit water by paying for equipment such are
borehole drills, pumps and pipes. Even roof gutters and water storage tanks may be
More affluent societies can afford to exploit water to develop more comfortable
lifestyles and industries that require more water. Irrigation may allow agriculture to
become more productive, possibly allowing the growth of new crops or cultivation
during periods with little rain.
Overexploitation of water resources by prosperous industries may reduce the amount
of water left for poorer sections of society, perhaps by reducing river flow or by