| 摘要: |
| 【目的】初步探讨区域干旱变化与厄尔尼诺/南方涛动(El Ni?o Southern Oscillation，ENSO)现象的关系，为青海东部高原农业区干旱的发生及干旱程度预测提供参考。【方法】基于1959－2005年的海表温度距平指数SSTA(Sea surface temperature anomaly)和南方涛动指数SOI(Southern oscillation index)及青海省东部农业区12个站点的降水指数，对海表温度距平SSTA和南方涛动指数SOI进行相关性分析，定义出厄尔尼诺(El Ni?o)事件和拉尼娜(La Ni?a)事件；计算标准化降水指数SPI(Stangard precipitation index)，对标准化降水指数SPI和海表温度距平SSTA以及南方涛动指数SOI进行相关性分析；采用谱分析的方法分析SSTA、SOI和干旱的周期变化规律。【结果】对1959－2005年的青海省东部农业区12个站点SPI指数的计算表明，该区中部和北部地区干旱程度较为严重；用南方涛动指数SOI定义的ENSO现象在滞后2个月时与12个站点的SPI指数有很大的正相关性，且显著性最高；对3个指数的谱分析表明，SSTA的明显周期有3个，SOI的明显周期有5个，其中45个月是两者共有的显著性周期，青海省东部农业地区的干旱周期较ENSO事件的周期短，但很接近。【结论】El Ni?o事件和La Ni?a事件对青海省东部农业地区干旱的影响基本相同，但在一些特大干旱事件发生时都为El Ni?o事件发生年，相对于La Ni?a事件，El Ni?o事件对青海省东部农业地区干旱的影响更大。 |
| 关键词: 青海东部农业区 ENSO现象 干旱事件 相关分析 谱分析 SPI指数 |
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| 基金项目:国家“863”高技术研究发展计划项目(14110209)；国家科技支撑计划项目(2011BAD29B01)；中央高校基本科研业务费科研创新重点项目(Z109021202) |
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| Response of drought in eastern Qinghai agricultural region to ENSO |
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LIU Lei,ZHANG Xin
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| Abstract: |
| 【Objective】This study preliminarily investigated the relationship between regional drought change and ENSO (El Ni?o-Southern Oscillation) phenomenon to provide basis for predicting occurrence and degree of agricultural drought in eastern Qinghai plateau.【Method】Based on sea surface temperature anomaly sea surface temperature anomaly (SSTA) and Southern oscillation index (SOI) during 1959-2005 years and precipitation indexes measured at 12 sites in eastern Qinghai agricultural area,correlation analysis between SSTA and SOI was conducted and ENSO and La Ni?a events were defined.Standard precipitation index (SPI) was calculated and its relation with SSTA and SOI was determined.At last,the periodic variations of SSTA,SOI,and draught were analyzed using spectral analysis method.【Result】SPI indexes showed that the drought degrees in central and northern areas were severer.ENSO phenomenon defined by SOI lagged by two months had large significantly positive correlation with SPI.Spectral analysis of the three indexes showed that SSTA had three clear cycles while SOI had five,and the cycle of 45 months was shared by them.The drought cycle in eastern Qinghai agricultural region was slightly shorter than that of ENSO events.【Conclusion】El Ni?o and La Ni?a events had similarly influence on regional drought in eastern Qinghai agricultural region,and the effect of El Ni?o was larger. |
| Key words: eastern Qinghai agriculture region ENSO phenomenon drought event correlation analysis spectral analysis standard precipitation index |
