我国西南地区东部夏季降水的时空特征  

Spatial-Temporal Characteristics of Summer Precipitation in the East of Southwest China

作　　者：李永华[1,2] 徐海明[1] 白莹莹 李强[1] 何泽能 

机构地区：[1]南京信息工程大学气象灾害省部共建教育部重点实验室,江苏南京210044 [2]重庆市气象科学研究所,重庆401147

出　　处：《高原气象》2010年第2期523-530,共8页Plateau Meteorology

基　　金：国家自然科学基金项目(40975058);重庆市自然科学基金计划重点项目(CSTC;2008BA0022);中国气象局省所科技发展专项(CMATG2008S09);重庆市气象局科技计划项目(zl-200810)共同资助

摘　　要：利用1959—2006年西南地区东部20个测站和中国740个测站的逐日降水量资料,采用EOF、Mann-Kendal、MESA(最大熵谱分析)、Morlet小波、线性相关等方法,分析了西南地区东部夏季降水的时空演变特征。结果表明:西南地区东部夏季降水量大体分为3种类型,即全区域一致型、南北相反型和东西相反型,其中全区域一致型是西南地区东部夏季降水最主要的分布型,出现频率达到60%以上。在整个时间域内,西南地区东部夏季降水略有增加的趋势;在20世纪60年代和70年代总体偏旱,而在80年代前期总体偏涝,80年代中后期开始波动加剧,旱涝交替发生,但总体相对偏涝;21世纪初以来,西南地区东部总体偏旱;1959年以来,1998,1980和1993年是降水偏多最明显的年份,而2006年和1972年降水偏少最明显。西南地区东部夏季降水的年际及年代际变化特征均较明显,存在2～3年、15年左右的显著周期。西南地区东部与宜宾以下的整个长江流域和西藏东部及川西高原的降水呈显著正相关,而与华南及东南沿海地区、华北中部和四川盆地西部地区呈显著负相关。Based on the daily precipitation data at 20 stations in the east of Southwest China from 1959 to 2006 and daily rainfall data at 740 stations of China,the spatial-temporal evolution features of summer precipitation in the east of Southwest China were studied,using the EOF,Mann-Kendal,MESA,Morlet wave and linear relevance methods.The results show that the precipitation can be divided into three kinds of distributed types,roughly,namely entire regional distribution type,north and south opposite distribution types and west and east opposite distribution types,in which the entire region type is the dominant one and reaches a frequency of more than 60 percent.The summer precipitation presents upward tendency during the discussion phase.The results also show that it is the drought period from 1960s to 1970s,the flood period in the beginning of 1980s and the dryness and the wetness perturbation reinforced and presentation alternately between the middle and the end of 1980s,in which generally the flood is dominant.It is the drought period since the beginning of the 21th centuries.The most obvious years of more precipitation present especially in 1998,1980,1993 since 1959,while the opposite facts present in 1972 and 2006.The interannual and the decadal periodic variation of the summer precipitation are remarkable.There are periodic change of 2～3 and 15 years primarily.The positive correlaltion is obviously between the precipitation in eastern region of Southeast China and regions from Yibin city to Changjiang River Basin,the southeastern of Sichuan and Yunnan Plateau,while the negative correlation is between the studying area and the Sichuan Basin and the edge of Sichuan Province,the centre of North China,the South China and the Southeast Coast of China.

关 键 词：西南地区东部 夏季降水 时空特征 

分 类 号：P463.1[天文地球—大气科学及气象学]