From 60 to 80 percent of the industrial demand is for cooling water, mainly in electricpower generation.

irrigation about 1,000 tons of water must be "consumed," that is, changed by soil evaporation and plant transpiration from liquid to vapor.

Wheat, rice and cotton fiber respectively require about 1,500, 4,000 and 10,000 tons of water per ton of crop.

of water per year. In the wealthier nations, where the diet is commonly more than 3,000 calories per day, the agricultural water requirement is 400 cubic meters per year.

on average, each person on the earth needs a minimum of 1,000 cubic meters (m3) of water per year—equivalent

For example, about half the water provided for irrigation is lost in transport, and less than half the water that reaches the fields is utilized by plants.

Illiteracy, malnutrition and disease; poverty so harsh that the farmer does not dare risk innovation because failure will mean starvation; small and fragmented farm

The total amount of rain and snow falling on the earth each year is about 380 billion acre-feet: 300

Even agriculture, man's principal consumer of water, takes little of the available supply. A billion acre-feet per year—less than 4 per cent of the total river flow—is used to irrigate 310 million acres of land, or about 1 per cent of the