中文摘要：

为了正确评价灌区的干旱状况,利用泾惠渠灌溉试验站1953—2011年的降水资料,分析了降水距平百分率、标准化降水指数SPI、降水Z指数三种干旱指标在灌区的适用性。结果表明,三种指标均能较好地体现降水的年际变化趋势,但SPI对于降水变化的反映比降水Z指数和降水距平百分率更准确。在干旱出现年份的判定方面,三种指标得到的结果一致;在干旱程度的判定上,在发生中旱及以上干旱的1969、1986、1993、2000年,SPI和降水Z指数比降水距平百分率判定准确,在发生重旱的1977、2000年,SPI的判定比Z指数更符合实际。分析泾惠渠灌区SPI变化趋势发现,灌区在1990年后干旱发生次数占研究期内总干旱次数的55.6%,干旱程度也有增加的趋势,采取合理措施抗旱将成为灌区未来发展的关键。

英文摘要：

In order to assess the regional drought condition accurately,precipitation anomaly（ Pa）,standard precipitation index（ SPI） and Z index were calculated and their suitability was compared based on the precipitation data of Jinghuiqu experimental station from 1953 to 2011. The results showed that all these indices could reflect the yearly change trends of precipitation,in which,SPI was more sensitive to the change of precipitation than Z index and Pa. In the judgment of drought occurrence,Pa,SPI and Z index showed consistent results; in the judgment of drought degree,SPI and Z index were more accurate than Pain 1969,1986,1993 and 2000 in which moderate or heavy drought happened,while SPI conformed to reality better than Z index in 1977 and 2000 in which heavy drought happened. Through the analysis of SPI change trend in Jinghuiqu irrigation district,it was discovered that55. 6% of drought events occurred after 1990 and drought degree also tended to increase during the study period.In the future,it is of great importance to take rational measures to prevent and control drought in this district.