以渭河上游灞河流域为研究区域，构建了SWAT分布式水文模型并进行水文过程模拟，得到土壤含水量模拟数据，据此计算获取土壤相对湿度。将计算结果作为农业干旱评价指标，对该流域的旱情等级进行评价。结果显示，2001年和2002年灞河流域春旱严重，2003年伏旱明显，这与流域记载的实际旱情描述大致吻合。研究表明，SWAT模型对于土壤墒情资料缺乏地区的农业干旱评价工作，具有一定的适用性。

The objective of this study is to evaluate the applicability of SWAT model to agricultural drought evaluation for regions without or lack of soil moisture data. For this purpose, the SWAT model was applied to simulate the hydrological process in the Bahe watershed of the upper Weihe River. The soil water content was obtained and it was used to calculate the relative soil moisture. The calculated relative soil moisture was regarded as the evaluation index of agricultural drought. The results showed that severe spring droughts occurred in 2001 and 2002 and summer drought occurred in 2003 in the Bahe watershed, which was in accordance with the actual conditions. . Therefore, SWAT model is applicable to agricultural drought evaluation for the area lack of soil moisture data.

国家重点基础研究发展计划（973计划）（2010CB9511）；水利部公益性行业科研专项项目（200901022）