近58年大汶河流域降水量演变特征分析

为进一步系统识别气候变化背景下大汶河流域降水量演变特征,基于大汶河流域32个雨量站1956~2013年逐日降水资料,分析了大汶河流域降水量年内分配与年际变化特征及趋势性、随机性、突变性、周期性的变化规律。结果表明,大汶河流域降水量年内分配不均,连续最大四个月均出现在6~9月,所占比例超过70%;年际变化较大,各分区多年平均降水量极值比分布在3.71~5.26之间;降水量呈现不显著下降趋势;降水序列并非完全独立,表现为正持续性;降水量在1964年发生不显著突变,降水量变化周期以14年为主。

Study on Characteristics of Precipitation Variation in Dawenhe Basin during Last 58 Years

Based on the precipitation data (1956-2013) collected from 32 rainfall stations in Dawenhe basin, we analyzed the annual distribution and the inter-annual variation of the precipitation and studied the tendency, the randomness, the sudden change and the periodicity of its change pattern. The results show that the annual distribution is uneven; maximum precipitation for 4 consecutive months appears in June to September, the proportion is up to 70%. There was a great change in the annual precipitation. The extremes ratio of the annual precipitation distribute in 3.71-5.26. The precipitation of Dawenhe basin mainly has a declining trend, but the trend is not remarkable. The precipitation series is not completely independent, while it has a positive persistence. The sudden change point appeared in 1964, but it was not obvious. The main change cycle of precipitation is 14 a.