云南省滇中地区气象干旱特征分析

Analysis on Characteristics of the Meteorological Drought in Central Yunnan

[目的]分析云南省滇中地区气象干旱特征。[方法]根据滇中地区43个气象站自建站以来的降水资料,分别计算各站年时间尺度的标准化降水指数(SPI),并统计不同等级干旱出现的频次,最后利用样条曲线插值法获取滇中地区不同干旱等级出现频率的空间分布特征。[结果]滇中地区自1960年以来旱情趋势经历了以下4个阶段:20世纪70年代SPI减小趋势比较明显,干旱有加重趋势;60、80年代SPI变化波动比较大,但无明显变化趋势;20世纪80年代后期一直到2000年SPI呈明显的增加趋势,即这一时期为滇中湿期;2001～2009年滇中干旱又呈增加趋势。红河、元江、宾川、禄劝、沾益等地发生中等干旱频率较高;昆明、呈贡、曲靖、楚雄东北部、大理、漾濞东部、玉溪中部等地发生严重干旱频率较高;沾益、宾川、大姚西部、祥云、曲靖北部、安宁、昆明西北部等地发生极端干旱频率较高。[结论]该研究为该地区防旱抗旱提供理论依据。

[ Objective] The research aimed to analyze characteristics of the meteorological drought in central Yunnan. [ Method ] Based on precipitation data at 43 meteorological stations of the central Yunnan, SPI at year scale in each station was calculated, and occurrence fre- quency of the drought at different grades was conducted statistics. Finally, the spline curve interpolation method was used to acquire the spatial distribution characteristics of the occurrence frequencies of the various-level droughts in Central Yunnan. [ Result] The drought has experi- enced the following four stages since 1960 in central Yunnan. Firstly, SPI had obvious decrease trend, and drought had the tendency to be- come severe in the 1970s. Secondly, in the 1960s and the 1980s, although variation of the SPI was large, we didnl find any distinct changing trend. Thirdly, SPI showed an evident increasing trend from the late 1980s to 2000. That was to say, central Yunnan experienced a wet period within those years. Lastly, the drought became severe from 2001 to 2009. Honghe, Yuanjiang, Binchuan, Luquan and Zbanyi tended to suffer from the medium drought; Kunming, Chenggong, Qujing, northeast Chuxiong, Dali, east Yangbi and central Yuxi tended to suffer from the sever drought; Zhanyi, Binchuan, west Dayao, Xiangyun, north Qujing, Anning and northwest Kunming tended to suffer from the extreme drought. [ Conclusion ] The research provided theoretical basis for drought prevention and control in the zone.