贵州省近50年降水量时空分布及变化特征

基于贵州省19个站点1960~2009年月降水资料,运用降水集度、气候趋势系数、Mann-kendall突变检验法、滑动T检验及小波分析等方法,分析了贵州省降水在不同时间尺度下的时空规律。结果表明,贵州省年降水量空间分布不均,整体呈东多西少的分布趋势,并形成了三多三少的降水集中区;近50年降水量呈下降趋势,年内降水呈季节性变化,春、秋季降水量有显著下降趋势,夏、冬季降水量呈上升趋势但不显著;贵州省年降水量存在22年左右的周期变化,在1984、1991、2001年发生突变,各季节周期变化和突变位置有所差异,这均增强了极端气候事件发生的概率,加剧了农业旱灾发生的风险。

Spatial and Temporal Distribution and Variation Characteristics of Rainfall in Guizhou Province in Recent 50 Years

Based on the monthly precipitation data of 19 meteorological stations from 1960 to 2009 in Guizhou province, the methods, such as precipitation concentration index (PCI), climate tendency coefficient, Mann kendall test, sliding T test and wavelet analysis, were employed to analyze temporal and spatial variation of precipitation in different time scales. The results show that the spatial distribution of annual rainfall is very uneven. Rainfall distribution increased gradually from west to east while the formation of three precipitation abundant places and three precipitation poor places. Annual precipitation appeared downward trend during the recent 50 years and it presented seasonal variation during the whole year. Precipitation in spring and autumn exhibited significant decreasing trend; in contrast, there was not an obvious upward trend for precipitation in summer and winter. There was an obvious periodic oscillation in annual precipitation, and 22 years was the first primary period. Abrupt change points of annual precipitation was at 1984, 1991 and 2001, respectively. There were different abrupt changes and periods in seasonal precipitation. Changing in precipitation of different time scales increase the probability of extreme precipitation event and intensify the risk of agricultural drought disaster.