聊城市降水变化特征与周期分析

Analysis on Change Characteristics and Periodicity of Precipitation in Liaocheng City

利用聊城市8个气象站点的降水资料,采用Arc GIS的克里格插值方法、线性回归、M-K突变检验、小波分析等方法分析了聊城市降水的时空分布特征。结果表明,1962—2015年年降水及夏、秋、冬季均呈现不显著减少趋势,春季降水为增加趋势。突变检验发现,各年及各季节均有突变发生的年份,其中春季降水在1990年前后突破显著性检验,降水表现为明显的增加趋势;年降水小波分析中,旱涝较为频繁,经历了降水的偏多—偏少—偏多—偏少的循环交替变化,年降水主周期为3~4年,季节降水周期各不相同,以周期3年为主。

Based on the precipitation data of eight meteorological stations in Liaoeheng City,the spatial and temporal distribution of precipitation in Liaocheng City was analyzed by using the methods of Kriging interpolation of ArcGIS,linear regression,M-K abrupt change test and wavelet analysis. The results showed that in recent 54 years,annual precipilation and precipitation of summer,autmnn and winter presented insignificant decreasing trends, spring precipitation presented an increasing trcnd. The abrupt change test showed that there were abrupt change years of annual and seasonal precipitation, in which the spring precipitation showed a significant increasing trend around 1990. The wavelet analysis of annual precipitation showed that the drought and flood were more frequent ,which presented a more-less-more-less cyclic alternation ,and the main precipitation cycle was 3-4 years. Seasonal precipitation cycle was different, mainly was 3-year cycle.