The
Water Cycle
Source:Illustration
by John M. Evans USGS, Colorado District (http://ga.water.usgs.gov/edu/watercyclegraphichi.html)
The water cycle is the
process by which our freshwater is produced. It breaks down into
several different stages. According to the Department of Atmospheric
Sciences at the University of Illinios at Urbana-Champaign,"The
hydrologic cycle begins with the evaporation of water from the surface
of the ocean. As moist air is lifted, it cools and water vapor condenses
to form clouds. Moisture is transported around the globe until it
returns to the surface as precipitation. Once the water reaches
the ground, one of two processes may occur: 1) some of the water
may evaporate back into the atmosphere, or 2) the water may penetrate
the surface and become groundwater. Groundwater either seeps its
way to into the oceans, rivers, and streams, or is released back
into the atmosphere through transpiration. The balance of water
that remains on the earth's surface is runoff, which empties into
lakes, rivers and streams and is carried back to the oceans, where
the cycle begins again."
Source:Universty
of Illinois WW2010 project. (http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/hyd/smry.rxml)
Facts
& Figures About the World's Freshwater
- Water covers 75% of
the Earth's surface. The total amount of water on Earth remains
about the same from one year to the next, as it circulates between
the oceans, land and atmosphere in a cycle of evaporation and precipitation.
This hydrological cycle is fundamental to the functioning of the
Earth as it recycles water, and has a role in modifying and regulating
the Earth's climate.
- Nearly 98% of the
Earth's water is in the oceans. Freshwater makes up less than 3%
of water on earth, and over two-thirds of this is tied up in polar
ice caps and glaciers. Freshwater lakes and rivers make up only
0.009% of water on Earth and groundwater makes up 0.28%.
- Water is essential
for all life forms. For example, it makes up 60 to 70% by weight
of all living organisms and is essential for photosynthesis. The
viability of all life on Earth is determined chiefly by the presence
of water, which is not evenly distributed on the planet. If it were,
it would cover the entire surface to a depth of 3 km (nearly five
miles).
Source:BBC
Science & Nature Homepage. (http://www.bbc.co.uk/nature/environment/conservationnow/global/freshwater/)
It seems that the most
relative fact is that while three-quarters of the Earth's surface
is covered with water, less than one percent (0.37% to be exact)
of that water is drinkable. Furthermore groundwater, where we place
pumps for wells, only accounts for 0.28% of freshwater across the
globe.
Cultural
& Religious Significance of Water
We cannot
however, simply define water as a commodity to be assessed a value
and sold. Water is a basic human right and something of significance
to all cultures across the globe. It is considered sacred as the
source of life, and as a purifying agent, in many religions. Every
religion has some sort of belief or practice involving water, giving
it an honored, or even sacred position in many rituals. Water is
central to the religious practice of all indigenous peoples as well
as to the beliefs of the major world religions.
Buddhism-
Buddhist monks pour water into a bowl and place it before a
dead body and other monks in attendance at a funeral.
Christianity-
Water is used in baptism rites, a public declaration and acceptance
of faith; an individual may be either sprinkled with water or fully
immersed, or anywhere in between. Water represents purification
and rejection of Sin. In the New Testament the "living water"
or "water of life" represents the spirit of God, and eternal
life.
Hinduism-
Water represents spiritual purification to Hindus, for whom bathing
is a morning ritual. Oftentimes there are pilgrimages to one of
the seven sacred rivers of India: the Ganges, Godavari, Kaveri,
Narmada, Sarasvati, Sindhu and Yamuna. Water is also used in funeral
rites.
Islam-
For Muslims, water serves as the key means of purification, or cleansing
the soul. There are three sorts of ablutions: The first and most
important involves washing the whole body; it is obligatory after
sex, and recommended before the Friday prayers and before touching
the Koran. Secondly, before each of the five daily prayers Muslims
must bathe their head, wash their hands, forearms and feet. All
mosques provide a water source, usually a fountain, for this ablution.
When water is scarce, followers of Islam use sand to cleanse themselves;
this is the third form of ablution.
Judaism-
Jews use water for ritual cleansing, to restore or maintain a state
of purity. Hand-washing before and after meals is obligatory. Although
ritual baths, or mikveh, were once extremely important
in Jewish communities, they are less so now; they remain, however,
compulsory for converts. Men attend mikveh on Fridays and
before large celebrations, women before their wedding, after giving
birth and after menstruation. The first book of the Bible, Genesis,
tells the story of Creation and of the Great Flood. To punish humans
for their disobedience, God sent a torrential rain down upon the
Earth, for forty days and forty nights. Safe on an ark, Noah, his
family, and two of each species of animal alone were spared. The
flood washed away the sins of the world so that it could be reborn,
free from impurity.
Source:International
Year of Freshwater 2003