锡林浩特市50年降水量变化特征分析

Precipitation Variation Characteristics of Xilinhot City for 50 Years

为了预估锡林浩特市未来降水演变趋势,为制定流域治理规划以及合理开发利用水资源提供理论依据,利用气候趋势分析、小波分析和M-K突变检验等方法,分析锡林浩特市1961—2010年50年降水的多时间尺度变化特征。结果表明:年降水量呈弱减少趋势,夏季和秋季呈减少趋势,夏季尤为明显,但夏季降水量对年降水量的贡献最大;春季和冬季虽呈弱增加趋势,且春季大于冬季。各月降水量呈现出偏多和偏少波动变化趋势,其中减少最多的是8月,其次是7月。年降水量历史极大值出现在1974年,极小值出现在2005年,极差达359.9mm。多雨期出现在20世纪60年代末期—70年代末期以及90年代,少雨期出现在20世纪60年代和2l世纪初。降水量变化存在明显的多时间尺度变化特征,变化周期在小尺度上变化频率较高,而在大尺度上相对较低,分别以2～5年和10年左右周期表现显著。1999年是50年年降水量变化的显著突变点,由多雨期转为少雨期。

In order to estimate the region ＇ s future evolution trend of precipitation and the development of watershed management planning and the rational exploitation and utilization of water resources to provide a theoretical basis,using climate trend analysis,wavelet analysis and M-K mutation testing methods,such as analysis of Xilinhot 50 years rainfall from 1961 to 2010,the multi-time scale variations.The results showed that：weakly decreasing trend of annual precipitation,summer and autumn showed a decreasing trend,especially in summer,but summer precipitation for the largest contribution to annual precipitation;spring and winter,although weakly increasing trend,and in the spring than in winter.The monthly rainfall above normal and below normal fluctuations showed a trend,which was the largest decrease in August,followed by July.Historical annual precipitation maxima was in 1974,the minimum in 2005,and the range of 359.9 mm.Rainy period in the late 1960s-late 1970s and 1990s,the dry period in the 1960s and the 2l century.More obvious changes in precipitation time scale variations,changed in cycle changes in small scale high frequency,while in a large scale was relatively low,respectively,2-5 years and 10 years around the cycle performance significantly.50 years annual precipitation in 1999 was a significant change in mutation point,by the rainy period to dry period.