【摘要】 基于1961～2012年逐日气象及同期4个气候因子资料系列,采用标准化降水蒸散发指数(SPEI)定量描述兰州地区干旱状况,利用M-K检验分析了该地干旱变化趋势,采用皮尔逊相关系数法以及交叉小波变换法研究了SPEI与北大西洋涛动(NAO)、北极振荡(AO)、太平洋十年涛动(PDO)以及厄尔尼诺-南方涛动(ENSO)四个气候因子之间的关系。研究结果表明:干旱指数SPEI在月、春、夏、秋及年尺度上均呈显著下降趋势、冬季增长趋势不显著,未来兰州春、夏和秋季缺水有加重趋势,冬季有变湿润倾向;SPEI与PDO、ENSO在秋季呈显著负相关;ENSO主要影响干旱短周期的年际变化;干旱与PDO和AO呈滞后的负相关关系,两指数主要影响较长周期干旱的年际和年代际变化。更多还原

【Abstract】 The drought in Lanzhou area was quantitatively described by the standardized precipitation evapotranspiration index(SPEI) using the daily meteorological data and four climatic factors(North Atlantic Oscillation(NAO), Arctic Oscillation(AO),Pacific Decadal Oscillation(PDO) and El Nino Southern Oscillation(ENSO)) series of 1961-2012. The results demonstrate that the drought index SPEI decreases significantly on a monthly, seasonal and annual scale, except showing an insignificant growth trend in winter. In general terms, it is suggested that the water shortage in Lanzhou would increase in spring, summer and autumn, but tend to be humid in winter in the future. SPEI has a significant negative correlation with PDO and ENSO in autumn. ENSO mainly affects the interannual change of short-term drought. Drought has a negative correlation with PDO and AO, and the two indices mainly affect the interannual and decadal variation of long-term drought.更多还原