1959-2007年安徽省降水时空变化特征分析

利用安徽省1959-2007年的逐日降水资料,采用线性回归法、Mann-Kendall法、累积距平法和Morlet小波分析方法,分析了近49a降水变化趋势及变化特征。结果表明,安徽地区夏季和冬季降水有显著的增加趋势(P<0.05),春、秋季和年降水量的变化趋势不显著。全区年降雨日总数有极显著的减小趋势(P<0.01),但暴雨日数却有所增加。雨日总数自南向北递减,但暴雨日数的气候倾向率却有自南向北增加的趋势。全省年降水量和四季降水量大致存在两个主周期的变化,2～4a周期震荡趋势逐渐明显。安徽地区雨日减少,强降水增加,降水有集中化趋势。20世纪90年代中期以后,降水宽幅震荡趋势凸显,不确定性增加,导致旱涝灾害发生可能性增加,会对当地农业生产带来不利影响。

Analysis of Spatial-temporal Precipitation Variation in Anhui Province during 1959-2007

Based on daily precipitation data of sixteen meteorological stations in Anhui province during 1959 to 2007,using linear regression method,Mann-Kendall method,accumulative anomaly method and Morlet wavelet analysis method,the characteristics and tendencies of annual precipitation variation were analyzed.The results showed that the trend of annual precipitation increased unsignificantly.The linear increase trend was significant in summer and winter,but decrease trend in spring and autumn were not obvious.There was a significant decrease trend for annual total rain days in all areas,but the heavy and rainstorm days was increased.The total rain day was reduced from south to north,but the change rates of ≥25mm rain day is increased from the same direction.Both annual precipitation and seasonal precipitation presented two kinds of period,and 2～4 years cycle concussion was obvious.In Anhui province,the precipitation was more centralized because of less rain days and more rainfalls.Since the mid 1990s,the annual precipitation presented more prominent wide range shock and uncertainly,resulted in more drought and flood disasters and bringing bad effect of the local agricultural production.