金沙江元谋干热河谷区水热变化的多时间尺度分析

Multi-time Scale Analysis of Hydrothermal Changing in Yuanmou Dry-hot River Valley of Jinsha River

为揭示金沙江元谋干热河谷区水热变化状况,采用小波分析方法,具体分析了元谋年均气温、年降水量序列中存在的多时间尺度特征。结果表明:元谋干热干热河谷区自1955年以来气温一直呈现出降低的趋势,而降水量则有微弱增加的倾向;从小波变换实部和模值可以看出,元谋年平均气温序列在25年和7年左右时间尺度的振荡最为明显,而降水量则在28、18年时间尺度的振荡最为强烈;就周期性特征,年均气温有7年和25年左右的时间周期,其中25年的周期最明显,降水量则有4、9、18年和28年左右的时间周期,长周期比短周期显著;对于突变特征,年均气温对应于25年和7年时间尺度的突变分别有4次和14次,年降水量对应于28、18、9年和4年时间尺度的突变有分别有4、6、12次和28次。

In order to reveal the hydrothermal change in the dry-hot river valley of Jinsha River,the wavelet analysis method was used to analyze the multi-time scale characteristic existing in the annual average temperature and precipitation sequences of Yuanmou.The results showed that the temperature in Yuanmou dry-hot valley area had shown decrease trend since 1955,while the precipitation had increase tendency.From the modulus and the real part of wavelet transform,it can be found that the oscillation of annual average temperature series in Yuanmou was the most obvious on the time scale of 25 years and 7 years,and the oscillation of precipitation was the most strong in the time scale of 28 years and 18 years.For the periodicity,the annual average temperature had the period about 7 years and 25 years,in which the most obvious period is 25 years time scale.The precipitation had the time scale period of 4 years,9 years 18 years and 28 years,the long time period were significantly than the short time period;For the mutation characteristics,the annual average temperature corresponding to 25 years and 4 years time scale had 4 and 14 times mutation,respectively,while the annual precipitation corresponding to 28 years,18 years,9 years and 4 years time scale had 4 years,6 years,12 years and 28 years mutation,respectively.