A Lot and little enough

Ours is a unique planet in the system. Oceans and seas cover two-thirds of its surface and perhaps it should have been named water rather than earth. Water is not a rarity even on land; lakes sparkle, ribbons of rivers wind across the continents, glaciers and the vast ice-and-snow shields of Greenland and the Antarctica glitter in the sun. In the northern hemisphere every winter snow and ice cover more than third of all land surfaces.

Scientists hold that water was born in the earth’s entrails at the dawn of its life. Somewhere inits depth the birth of water continues to this day. Today with lava, volcanoes annually eject 40 million tonnes of water. Thus, little by little, the amount of water on the earth’s surface increases.

Unfortunately, 97.5 per cent of all water reserves are claimed to be salt water. Consequently, fresh water resources account for only 2.5 per cent and the most accessible as little as o.3 per cent. Moreover, the natural distribution is extremely uneven. The annual fresh water discharge into the ocean is the greatest in Asia and South America – 31 and 25 per cent of the total amount respectively, North America accounts for 17, Africa 10, Europe 7, Antarctica 5 and Australia 4 per cent.

The river watermark is also uneven during the year. From May to October all rivers discharge 63 per cent of their annual runoff, leaving only 37 per cent for the rest of the year.

The authors of the monograph estimate that the annual satisfaction of human requirements runs to something like 2.600 cubic kilometres of water – about 6 per cent of the earth’s annually renewable fresh water resources. According to experts, by the year 2000, considering the growth of population, industry and agriculture the water requirement will reach 6.000cubic kilometers or about 13 per cent.

The conclusion would seem to be optimistic: our planet has sufficient water. Why then should scores of countries face a tight water balance/

The reason is that the unevenness of water distribution is aggravated by the still greater unevenness of the geographical distribution of people. The shortage strikes where there is an excess of population and industry. Besides, modern industry, with its manufacture of increasingly complex and diverse products, requires not just fresh, but exceptionally clean, freshwater, the quality of products being highly sensitive to various impurities. Many countries are short of this clean water.