基于MTM-SVD方法的攀西秋雨变化规律分析  

Spatio-temporal Variation Feature of Autumn Rain in Panxi Region Based on MTM-SVD Method

作　　者：王春学[1,2] 马振峰 毛家勋 WANG Chunxue;MA Zhenfeng;MAO Jiaxun(Sichuan Provincial Climate Center,Chengdu,Sichuan 610072,China;Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province,Chengdu,Sichuan 610072,China;Panzhihua Meteorological Office of Sichuan Province,Panzhihua,Sichuan 617000,China)

机构地区：[1]四川省气候中心,四川成都610072 [2]高原与盆地暴雨旱涝灾害四川省重点实验室,四川成都610072 [3]四川省攀枝花市气象局,四川攀枝花617000

出　　处：《水土保持通报》2018年第4期168-173,共6页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目"华西秋雨年际变化规律及其形成机理研究"(41275097);攀枝花市科技项目(2014CY-N-14)

摘　　要：[目的]研究四川省攀枝花市和凉山州(以下简称攀西地区)秋雨时空变化规律,为攀西秋雨气候预测和防灾减灾提供科学依据。[方法]利用1961—2017年攀西地区18个气象站逐日降水量资料,采用MTM-SVD等方法分析攀西秋雨的时空变化规律。[结果](1)攀西秋雨EOF展开第一模态为全区一致变化型,方差贡献率达46.1%,为攀西秋雨主模态,滑动t检验显示攀西秋雨主模态在1995年前后出现过一次显著突变。(2)1961—2017年攀西秋雨有显著的3.2a周期,滑动窗口分析显示1995年之前攀西秋雨的准3a周期非常明显,之后突然消失,转变为显著的准2a周期。(3)以1995年为节点分段研究,1961—1994年攀西秋雨3.4a周期达到了99%的置信度水平,3.0a周期达到了95%的置信度水平。攀西秋雨准3a周期典型循环重建表明,第1a攀西地区整体都为正异常,第2a正异常强度迅速减弱,大部分转变为负异常,第3a攀西大部的负异常强度有所增加,即1995年之前攀西秋雨主要表现为"偏强—偏弱—偏弱"的年际变化过程。(4)1995—2017年攀西秋雨2a周期达到了99%的置信度水平。准2a周期典型循环重建表明,第1a攀西秋雨为全区一致的正异常,第2a异常情况与第1a完全相反,即1995年之后攀西秋雨主要表现为强弱交替的异常演变。[结论]攀西秋雨在1995年前后出现气候突变,1961—1994年主要表现为准3a周期振荡,1995—2017年则以准2a周期为主。[Objective]Studying the spatial and temporal variations of autumn rain in Panxi region(Panzhihua City and Liangshan Prefecture)during 1961-2017,to provide bases for autumn rain prediction and preparedness against consequent disaster.[Methods]Based on the daily precipitation data from 18 meteorology stations in Panxi region during 1961-2017 and the multi taper method-singular value decomposition(MTM-SVD),the spatial and temporal variations of the autumn rain were analyzed.[Results]①The first mode of EOF expansion in the autumn rain was accordant all over the area and the contribution rate of variance was 46.1%,which is the main mode of the autumn rain.The sliding t test showed that the main mode of the autumn rain had a significant sharp change around 1995.②MTM-SVD analysis showed that the autumn rain had a significant 3.2 year period in 1961-2017.The slip window analysis showed that before 1995,the quasi 3 year cycle of the autumn rain was very obvious,and the latter period suddenly disappeared,which turned into a significant quasi 2 year cycle.③The 3.4 year cycle of autumn rain in 1961-1994 reached a level of 99%confidence,and the 3 year cycle reached a level of 95%confidence.The typical cycle reconstruction of the quasi 3 year showed that before 1995,the autumn rain was mainly characterized by the inter-annual change of“more-less-less”.④The 2 year cycle of autumn rain in 1995-2017 years reached a level of 99%confidence.The typical cycle reconstruction of the quasi 2 year showed that after 1995,the autumn rain main manifested an abnormal evolution of the alternation of strong and weak.[Conclusion]The autumn rain in Panxi region had an abrupt climate change before and after 1995.It was mainly quasi 3 year periodic oscillation before 1995,and then was replaced by quasi 2 year cycle.

关 键 词：攀西 秋雨 MTM-SVD 

分 类 号：P466[天文地球—大气科学及气象学]