1971—2010年上海市降水变化特征分析

基于1971-2010年上海市徐家汇站的日降雨资料，采用一元线性回归法、Mann-Kendall法和小波分析等方法，对上海市40年来的年代际降水、年降水、汛期与非汛期降水的变化和周期变化特征进行研究和分析，并对降水的频率特征和典型台风期间的暴雨特征进行了分析。结果表明：上海市年代际降水、年降水、汛期与非汛期降水均呈增加趋势；年降水和汛期降水的震荡周期吻合，主周期均为8a左右，汛期降水与年降水的变化趋势相似性很大，说明汛期降水量较大程度地决定年降水量；非汛期降水主周期为4a左右；小雨所占比例随年代逐渐减少，而暴雨所占比例随年代逐渐增多，台风期间的暴雨雨量高度集中，强度大。

Analysis of precipitation variation characteristics in Shanghai City over period from 1971 to 2010

Based on daily precipitation data at Xujiahui Station during the period from 1971 to 2010 , the characteristics of precipitation in Shanghai City over the past 40 years were analyzed using methods including the linear regression analysis method , Mann-Kendall testing , and wavelet analysis .The variations of inter-decadal precipitation , annual precipitation , and precipitation in flood and non-flood seasons were studied , and the characteristics of precipitation frequency and rainstorms during typical typhoons were analyzed .The results show that the inter-decadal precipitation , annual precipitation , and precipitation in flood and non-flood seasons all have an increasing trend .There is a principal periodic oscillation of eight years for the annual precipitation and flood season precipitation . The variation trend of the flood season precipitation is similar to that of the annual precipitation , indicating that the flood season precipitation dominates the annual precipitation to a great extent .The non-flood season precipitation has a principal period of four years .The percentage of light precipitation gradually decreases over decades , while that of rainstorms gradually increases over decades .During the typhoons , the rainstorm was highly concentrated , with greater intensity .