Applications of Hydrogeology - Hydrogeology: Objectives, Methods, Applications - page 12

C HAPTER A3
Applications of Hydrogeology
1 WATER—SOURCE OF LIFE
Water is essential to human beings, who, at rest, consume two to three litres
per day, half of which is provided by food. In fact, the survival of all plant
and animal species depends on water, which makes up 70% of animals
and 90% of plants.
The water needs of humans have considerably increased over time
and touch on more and more numerous domains, in order to satisfy our
demands for comfort and pleasure, and to accomodate an increasing
economic demand.
Water consumption for domestic purposes has undergone a very
noticeable increase, independent of demographic progress (see chap. C1).
The average daily consumption per person today is over 200 liters, while
it was 160 liters in 1990, 145 liters in 1980, and 130 liters in 1975. Dietary
needs represent only a small portion of this quantity, on the order of 4%
(1% for drinking and 3% for cooking), and it is therefore the other uses of
water that have increased the most, following increases in quality of life
and comfort levels.
It has additionally been noted that, due to increasingly strict health
standards and to the recent development of deep wells, groundwater has
been increasingly exploited, as it is better protected from pollution than
surface water.
Other water uses do not require potable water, but represent the
majority of demand. Their progression over time is equally spectacular, for
the same reasons, as well as in response to the need for economic viability
and the demands of the market.
Aside from hydroelectric dams and cooling systems for nuclear power
plants, which consume large quantities of water but take them mainly from
rivers, other activities are relying more and more on groundwater resources,
easily accessible today and not directly influenced by the “reserved
discharge” required for surface waters.