白洋淀流域降水特性分析

选取白洋淀流域6 个雨量站1959 年- 2009 年日降水量资料, 并以此为基础运用滑动平均法、M ann2Kendall 非参数秩次检验法及小波分析法对该流域降水特性演变规律进行了分析。结果表明: 在流域内, 年降水量呈下降趋 势且主要由年降水日数显著下降引起; 年内各月降水量的不均匀程度呈减小趋势; 不同量级降水频率波动较小, 但 呈现小强度降水比例增加、较大强度降水比例减少的结构变化; 暴雨雨量和暴雨强度有较明显的下降趋势, 降水潜 力下降; 年降水量存在4 类尺度的周期变化规律, 其中16a 变化为主周期。 On the basis o f the daily precipitation data at 6 stations in the Ba iyangdian Basin fr om 1959 to 2009, the characterist ics of precipitation wer e analyzed using the mov ing aver age met ho d, Mann2Kendall test metho d, and wav elet analysis method. T he results show ed that the annual pr ecipitatio n amount decreased, which w as mainly caused by the sig nificant decline in the amount of pr ecipitatio n day s; the degr ee o f unev enness of monthly precipitation decreased; the precipitatio n frequency of diff er ent precip2 itation intensities w as stable, and the pr opor tion of pr ecipitatio n amount of smaller pr ecipitatio n intensity decreased w hile that of lag er precipitation intensit y increased; the amo unt and int ensity of heavy sto rm decreased significantly; and annual precipitatio n show ed four scale cycles, and 16a was the main cycle.