近几年来,世界上许多地区缺水现象愈来愈严重。联合国在1977年就向全世界发出警告“水不久将成为一项严重的社会危机,石油危机之后的下一个危机便是水”。我国水资源并不丰富,人均占有淡水量为世界人均占有淡水量的四分之一。北京全市水资源的人均占有量为世界人均占有量的二十五分 In recent years, water shortages have become more and more serious in many parts of the world. In 1977, the United Nations warned the world that “water will soon become a serious social crisis, and the next crisis after the oil crisis will be water.” China’s water resources are not abundant, and per capita possession of freshwater accounts for a quarter of the world’s per capita amount of freshwater. The per capita occupancy of water resources in Beijing is 25 points per capita in the world