According to a study published in the July 14, 2000, issue of Science, one-third of the world's population is water-stressed, with 8 percent classified as severely water-stressed, including the western United States and northern Mexico, South America, India, China, Africa surrounding the Sahara Desert, and southern Africa and Australia.
"Water stress" has profoundly different meanings in developed and developing countries. In Africa and many parts of Asia, it means inadequate water for drinking, sanitation and crops. In emerging economies such as India and China, it translates as an inability to meet the dietary and lifestyle aspirations of a growing middle class.