中文摘要：

比较分析了国内外有关地表水资源可利用量代表性定义,国内外在此问题上的区别主要在于是否考虑回归水、是否考虑无法控制利用的洪水以及是否充分考虑水权等。以水资源可利用量的概念为切入点,综述了国内外有关地表水资源可利用量的研究进展,着重介绍并比较分析了国内常用的扣损法、美国得克萨斯州的WAM模型和综合考虑水量与水质的墨西哥水资源可利用量指数法,指出了今后地表水资源可利用量计算的研究重点。

英文摘要：

　In this paper,several representative definitions for the available water resources were introduced and compared.It is pointed out that the main differences among these definitions lie in that whether the return water is calculated,or the uncontrolled flooding water is considered,and the water rights are emphasized,and so on.Based on the definition of the available water resources,the methods for calculating available surface water resources were summarized.Especially,three methods,the deduction method,the water availability model（WAM） of Texas,USA,and the Mexico water availability index method which integrates water quality and quantity,were introduced in details.The research focus in the calculation of available surface water resources in the near future was also pointed out.