India will be one of the 48 countries where one in three persons will face shortage of water by the year 2025, according to a study.Chronic shortage and pollution of water will be a major problem in India in the near future, warns the study by the Johns Hopkins Univeristy School of Public Health."China, with a population of 1.5 billion, will not be far behind," it says. According to the parameters of the study, a country faces "water stress" when annual water supplies drop below 1,700 cubic metres per person. Water-scarce countries have annual water supplies of less than 1,000 cubic metres per person.Currently it says, 31 countries face water stress or scarcity.