一、前言水是一种宝贵的资源。人们对水的看法已进入新的时代。过去人们都认为它是“取之不尽,用之不竭”的廉价品,从未把它看作资源,用户按各自的要求无节制的开采使用,而不是合理分配。现在人们才逐渐认识到它不仅是人类与其它一切生物生存的必要条件,也是国民经济发展不可缺少的重要资源。在缺水地区甚至把它提到了“资源的资源”的重要地位。 I. Introduction Water is a valuable resource. People’s perception of water has entered a new era. In the past, people considered it an “inexhaustible” bargain, never treating it as a resource. Instead of distributing it rationally, users used the uncontrolled exploitation of their own requirements. Now people gradually realize that it is not only a necessary condition for the survival of human beings and all other beings, but also an indispensable and important resource for the development of the national economy. It even mentioned it as a “resource of resources” in water-scarce regions.