[目的]研究近50年六盘水市雨季降水的变化规律.[方法]利用六盘水市六枝、盘县、水城3个测站1960～2009年5～9月的逐月降水量资料,采用线性倾向估计、滑动T-检验和Morlet小波分析方法,对近50年来六盘水市雨季降水的年际、年代际变化及突变特征等进行分析.[结果]近50年六盘水市雨季降水量呈下降趋势,其线性倾向率为-15.4 mm/10a.六盘水市雨季降水存在明显的年际、年代际变化特征;20世纪60年代中期为明显的少雨期,60年代后期降水相对偏多;整个70年代为相对少雨期;70年代末到80年代后期,雨季降水进入多雨期,是近50年来降水最多的时段;80年代末到90年代中期降水相对偏少,90年代中后期为多雨期,进入21世纪转为少雨期.滑动T-检验表明,近50年六盘水市雨季降水突变点在2002年.小波分析表明,六盘水市雨季降水具有显著的多时间尺度特征,在年代际尺度上存在显著的16年周期振荡,且50年来稳定存在;在年际尺度上,存在准8年的周期振荡.[结论]该研究为六盘水市旱涝灾害的准确预报和防灾减灾提供科学依据.%[Objective] The research aimed to study the variation rule of precipitation in the rainy season in Liupanshui City in recent 50 years. [ Method] Based on the monthly precipitation data from three observatories (Liuzhi, Panxian and Shuicheng) of Liupanshui City from May to September during 1960 -2009, the interannual, interdecadal variations and mutation characteristics of precipitation in the rainy season in Liupanshui City in recent 50 years were analyzed by using the linear tendency estimation, sliding T-test and Morlet wavelet analysis method.[ Result] The rainfall in the rainy season in Liupanshui City in recent 50 years presented the decline trend, and the linear tendency rate was - 15.4 mm/10a. The precipitation in the rainy season in Liupanshui City had the obvious interannual and interdecadal variation characteristics. It was the obvious rainless period in the metaphase of 1960s, and the precipitation was comparatively more in late 1960s. It was the relatively rainless period in the whole 1970s. From late 1970s to late 1980s, the precipitation in the rainy season entered into the pluvial period.It was the period when the precipitation was the most in recent 50 years. The precipitation was relatively less from late 1980s to metaphase of 1990s. It was the pluvial period in the middle and late periods of 1990s, and it was the rainless period when entered into the 21st century. The sliding T-test showed that the precipitation mutation point in the rainy season in Liupanshui City in recent 50 years happened in 2002. The wavelet analysis showed that the precipitation in the rainy season in Liupanshui City had the significant multiple time scale characteristic. In the interdecadal scale, the precipitation had the significant 16-year periodic oscillation which stably existed in 50 years. In the interannual scale, the precipitation had quasi-8-year periodic oscillation. [ Conclusion] The research provided the scientific basis for the accurate forecast of drought and flood disasters, disaster prevention and reduction in the city.
展开▼
