华中地区近45年来降水变化特征分析

CHARACTERISTICS OF PRECIPITATION IN CENTRAL REGION OF CHINA OVER45 YEARS

根据河南、湖北和湖南等3省55个气象站1961～2005年的逐日降水量资料,采用趋势分析、周期分析和突变检验等方法,揭示华中地区降水的时空变化特征。结果表明:(1)华中区域平均年降水量呈增加趋势,增速为18.6mm/10a,但大部分站点增加趋势不显著;(2)华中区域平均年降水日数呈不显著的上升趋势,上升速率为0.57d/10a,其中大部地区为增多趋势(占65.5%的站点);(3)全区平均年中雨、大雨和暴雨以上日数上升速率分别为0.39、0.22和0.093d/10a,通过显著性检验的面积也随着日雨量条件的升高而不断缩小;(4)从季节上来看,区域降水量和降水日数在春、秋季为减少趋势,冬、夏季为增多趋势;(5)年及各季节降水量和降水日数的周期振荡差异明显,年降水量、冬季降水量分别在1989和1982年出现突变,而夏季和冬季降水日数则分别在1981年和1969年发生突变,且均通过0.05的信度检验。

Based on daily precipitation data of 55meteorological stations in the central region of China in 1960～2005,method of trend analysis,spatial interpolation,wavelet analysis and mutation testing were used to obtain the temporal and spatial changes characteristics of precipitation.The results showed that:(1)the trend of annual precipitation is increasing at a climatic tendency of 18.6mm/10a,but the increasing trends of most sites are not significant;(2)there is no significant upward trend for annual precipitation days,and the increase rate is 0.57d/10a;(3)the increased rate of annual days of moderate rain,heavy rain and rainstorm are 0.39,0.22and 0.093d/10arespectively,and the number of sites is shrinking when the rainfall level improved;(4)precipitations in spring and autumn were decreasing in most of the areas,while precipitations in summer and winter were increasing,and the same as the precipitation days;(5)the oscillation periods of precipitation for year and seasons are not consistent,the annual and winter precipitation had abrupt change in 1989and 1982respectively,however the days of precipitation in summer and winter changed significantly in 1981and 1969respectively,all of which passed the reliability testing by 0.05.