Water – a colorless, transparent, odorless, tasteless liquid compound of oxygen

and hydrogen. The Concise Oxford Dictionary

Everyone understands that water is essential to life. But many are only just now

beginning to grasp how essential it is to everything in life – food, energy,

transportation, nature, leisure, identity, culture, social norms, and virtually all the

products used on a daily basis. With population growth and economic development

driving accelerating demand for everything, the full value of water is becoming

increasingly apparent to all.

Water is a common chemical substance that is essential for the survival of all known

forms of life. In typical usage, water refers only to its liquid form or state, but the

substance also has a solid state, ice, and a gaseous state, water vapor. About 1.460

petatonnes (Pt) of water covers 71% of the Earth's surface, mostly in oceans and other

large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air

as vapor, clouds (formed of solid and liquid water particles suspended in air), and

precipitation. Some of the Earth's water is contained within man-made and natural

objects near the Earth's surface such as water towers, animal and plant bodies,

manufactured products, and food stores.

Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%,

and other land surface water such as rivers, lakes and ponds 0.6%. Water moves

continually through a cycle of evaporation or transpiration (evapotranspiration),

precipitation, and runoff, usually reaching the sea. Winds carry water vapor over land

at the same rate as runoff into the sea, about 36 Tt per year. Over land, evaporation

and transpiration contribute another 71 Tt per year to the precipitation of 107 Tt per

year over land. Some water is trapped for varying periods in ice caps, glaciers,

aquifers, or in lakes, sometimes providing fresh water for life on land. Clean, fresh

water is essential to human and other life. However, in many parts of the world -

especially developing countries - it is in short supply. Water is a solvent for a wide

variety of chemical substances.

Types of water

Water can appear in three phases. Water takes many different forms on Earth:

water vapor and clouds in the sky; seawater and rarely icebergs in the ocean; glaciers

and rivers in the mountains; and aquifers in the ground. Water can dissolve many

different substances, giving it different tastes and odors. In fact, humans and other

animals have developed senses to be able to evaluate the potability of water: animals

generally dislike the taste of salty sea water and the putrid swamps and favor the purer

water of a mountain spring or aquifer. Humans also tend to prefer cold water rather

than lukewarm, as cold water is likely to contain fewer microbes. The taste advertised

in spring water or mineral water derives from the minerals dissolved in it, as pure H2O

is tasteless. As such, purity in spring and mineral water refers to purity from toxins,

pollutants, and microbes.

The major chemical and physical properties of water are:

1. 2. Water is a tasteless, odorless liquid at ambient temperature and pressure. The

color of water and ice are, intrinsically, a very light blue hue, although water

appears colorless in small quantities. Ice also appears colorless, and water

vapor is essentially invisible as a gas.

3. The boiling point of water (and all other liquids) is directly related to the barometric pressure. For example, on the top of Mt. Everest water boils at about 68 °C (154 °F), compared to 100 °C (212 °F) at sea level. Conversely,

water deep in the ocean near geothermal vents can reach temperatures of hundreds of degrees and remain liquid.

4. Water sticks to itself. Water has a high surface tension caused by the strong cohesion between water molecules because it is polar. The apparent elasticity caused by surface tension drives the capillary waves.

Capillary action refers to the tendency of water to move up a narrow tube against the

force of gravity. This property is relied upon by all vascular plants, such as trees.

Water on Earth

Water covers 71% of the Earth's surface; the oceans contain 97.2% of the

Earth's water. The Antarctic ice sheet, which contains 90% of all fresh water on Earth,

is visible at the bottom. Condensed atmospheric water can be seen as clouds,

contributing to the Earth's albedo. Hydrology is the study of the movement,

distribution, and quality of water throughout the Earth. The study of the distribution

of water is hydrography. The study of the distribution and movement of groundwater

is hydrogeology, of glaciers is glaciology, of inland waters is limnology and

distribution of oceans is oceanography. Ecological processes with hydrology are in

focus of ecohydrology. The collective mass of water found on, under, and over the

surface of a planet is called hydrosphere. Earth's approximate water volume (the total

water supply of the world) is 1 360 000 000 km³ (326 000 000 mi³). Of this volume:

1 320 000 000 km³ (316 900 000 mi³ or 97.2%) is in the oceans.

25 000 000 km³ (6 000 000 mi³ or 1.8%) is in glaciers, ice caps and ice sheets.

13 000 000 km³ (3,000,000 mi³ or 0.9%) is groundwater.

250 000 km³(60,000 mi³ or 0.02%) is fresh water in lakes, inland seas, and

rivers.

13 000 km³ (3,100 mi³ or 0.001%) is atmospheric water vapor at any given

time.

The human body is anywhere from 55% to 78% water depending on body size. To

function properly, the body requires between one and seven liters of water per day to

avoid dehydration; the precise amount depends on the level of activity, temperature,

humidity, and other factors. Most of this is ingested through foods or beverages other

than drinking straight water. It is not clear how much water intake is needed by

healthy people, though most advocates agree that 6–7 glasses of water (approximately

2 litres) daily is the minimum to maintain proper hydration. Medical literature favors

a lower consumption, typically 1 liter of water for an average male, excluding extra

requirements due to fluid loss from exercise or warm weather. For those who have

healthy kidneys, it is rather difficult to drink too much water, but (especially in warm

humid weather and while exercising) it is dangerous to drink too little. People can

drink far more water than necessary while exercising, however, putting them at risk of

water intoxication (hyperhydration), which can be fatal. The "fact" that a person

should consume eight glasses of water per day cannot be traced back to a scientific

source. There are other myths such as the effect of water on weight loss and

constipation that have been dispelled. Humans require water that does not contain too

many impurities. Common impurities include metal salts and/or harmful bacteria,

such as Vibrio. Some solutes are acceptable and even desirable for taste enhancement

and to provide needed electrolytes. The single largest freshwater resource suitable for

drinking is Lake Baikal in Siberia, which has a very low salt and calcium content and

is very clean.

Water politics and water crisis

Water politics is politics affected by water and water resources. Because of

overpopulation, mass consumption, misuse, and water pollution, the availability of

drinking water per capita is inadequate and shrinking as of the year 2006. For this

reason, water is a strategic resource in the globe and an important element in many

political conflicts. It causes health impacts and damage to biodiversity. The serious

worldwide water situation is called water crisis. UNESCO's World Water

Development Report (WWDR, 2003) from its World Water Assessment Program

indicates that, in the next 20 years, the quantity of water available to everyone is

predicted to decrease by 30%. 40% of the world's inhabitants currently have

insufficient fresh water for minimal hygiene. More than 2.2 million people died in

2000 from waterborne diseases (related to the consumption of contaminated water) or

drought. In 2004, the UK charity WaterAid reported that a child dies every 15 seconds

from easily preventable water-related diseases; often this means lack of sewage

disposal; see toilet. To halve, by 2015, the proportion of people without sustainable

access to safe drinking water is one of the Millennium Development Goals.

In 1999 the United Nations Environment Programme (UNEP) reported that 200

scientists in 50 countries had identified water shortage as one of the two most

worrying problems for the new millennium (the other was global warming. We use

about 70% of the water we have in agriculture. But the World Water Council believes

that by 2020 we shall need 17% more water than is available if we are to feed the

world. So if we go on as we are, millions more will go to bed hungry and thirsty each

night than do so already.

Today, one person in five across the world has no access to safe drinking water, and

one in two lacks safe sanitation.

Today, and every day, more than 30,000 children die before reaching their fifth

birthdays, killed either by hunger or by easily-preventable diseases.

And adequate safe water is key to good health and a proper diet. In China, for

example, it takes 1,000 tonnes of water to produce one tonne of wheat.

There are several reasons for the water crisis. One is the simple rise in population, and

the desire for better living standards. Another is the inefficiency of the way we use

much of our water. Irrigation allows wastage on a prodigal scale, with the water

trickling away or simply evaporating before it can do any good.

And pollution is making more of the water that is available to us unfit for use. The

Aral Sea in central Asia is one of the starkest examples of what pollution can do, to

the land as well as the water.

Water should be high on the business agenda because all businesses depend on water.

The continuity and future success of any business are impacted by the availability,

cost, and quality of water at many points along the ‘value chain’, including ‘upstream’

(in the production and supply of raw materials), ‘midstream’ (in what businesses

make from raw materials or other pre-processed inputs), and ‘downstream’

(consumers need water, and everyone needs water to be treated and recycled). Like

people and governments, businesses tend to ignore water until it becomes scarce,

polluted, too expensive, or in some way is mismanaged. But in the near future – as a

result of changes in both human and natural systems that affect water availability,

access, affordability, and quality – the water management challenges facing humanity

will become more complex. The prospect of water shortages, scarcities, and stresses

will increase.

Businesses cannot afford to ignore this trend. For some it means new economic

opportunities in making water available to meet demand or in fi nding solutions to

improve water quality and water use effi ciency. For others, it means closer scrutiny

of how they, their supply chains, and their markets access and use water, and of how

new business risks emerge as they compete with other users. In any case, it is time for

businesses of all sectors and sizes to add water to their strategic thinking.