辽宁省近54年旱涝特征分析及其对大气环流响应研究

在全球气候变暖背景下，探讨区域旱涝时空演变及成因对实现抗旱减灾和社会可持续发展至关重要。本文以辽宁省为研究基点，以标准化降水蒸散指数（SPEI）为旱涝量化指标，运用滑动平均、小波变换、经验正交分解等方法对辽宁省近54年旱涝时空演变特征进行分析，并结合太阳黑子和遥相关指数，运用交叉小波方法探讨旱涝特征对各因子的响应。结果表明：（1）时间尺度上，辽宁省SPEI指数存在29a的主周期和5a、9a次周期，且近54年以0.143/10a的速率向湿润化发展；（2）空间模态上，受大尺度气候系统的影响，第一模态表现为全区一致的湿润化趋势，东西反向差异为第二模态，反映了地理位置、海陆分布对SPEI指数的影响；（3）成因上，受太阳活动影响在太阳黑子数极值年份易发生旱涝灾害，两序列在时频上存在8~12a周期，表现为显著的反相位共振关系；SPEI与ENSO、NAO指数呈负相关，与PDO和AO指数呈正相关，且存在不同时间尺度的共振周期。

Analysis of drought and flood characteristics in Liaoning Province and its response to atmospheric circulation in the last 54 years

Under the background of global warming,it is very important to explore the spatial-temporal evolution and causes of regional drought and flood for the realization of drought relief and social sustainable development. In this paper,the spatio-temporal characteristics of drought and flood in Liaoning province in recent 54 years were analyzed on the basis of the standardized precipitation evapotranspiration index (SPEI), and the mathematical statistical methods such as moving average,wavelet transform and EOF Analysis. Combined with sunspot and teleconnection pattern indices, the response of drought and flood to various factors were explored by using the cross wavelet method. The results show that:(1) In terms of time scale, the SPEI of Liaoning Province has a main cycle of 29 years and a sub cycle of 5 years and 9 years, and it has been developing towards wetting at the rate of 0.143/10a;(2) There are two typical spatial distribution modes of SPEI in Liaoning Province:the first mode shows a consistent wetting trend throughout the region, and the other one shows the east-west reverse differences, reflecting the influence of large scale climate system, geographical location and land-sea distribution on SPEI index;(3) Due to the influence of solar activities,drought and flood disasters are prone to occur in the sunspot extreme years,with an 8-12a period, showing a significant inverse phase resonance relationship. In addition, SPEI is negatively correlated with ENSO and Nao indices, and positively correlated with PDO and AO indices, and there are resonance periods in different time scales.