一、定义的目的在全国性的水资源供需平衡研究中,引伸出不少的新概念。包括可供水量和可利用水量两个概念。虽进行过多次探讨,但由于南、北方情况不同,加之看法不一致,意见未能统一。以致在后来的水资源供需平衡研究中,虽常出现可供水和可利用水等概念,但各有各的含意。因此,有必要给可供水量和可利用水量下个定义。这至少有两点好处,一是能够统一概念,便于在国内进行学术交流,有利于水资源研究工作的深入开展。二是有了明确的定义,再利用电子计算机,可加快研究进度。前 First, the definition of the purpose of the national water supply and demand balance research, extended a lot of new concepts. Including the concept of available water and available water two concepts. Although many discussions have taken place, due to the different situations in the South and the North and the inconsistent views, opinions have not been unified. So that in later studies on the balance of supply and demand of water resources, concepts such as water supply and water availability often appear, but each has its own meaning. Therefore, it is necessary to define the available water quantity and the available water quantity next. There are at least two advantages. First, it can unify concepts, facilitate academic exchanges in China, and promote the further development of water resources research. Second, there is a clear definition, re-use of electronic computers, can speed up the progress of the study. before