赣江上游章水流域1955-2015年降雨量时空变化

为研究赣江上游降雨特征，以章水流域1955—2015年的22个雨量站日降雨资料为基础，对各站雨量及流域面雨量序列分别采用线性回归、滑动平均、Mann-Kendall趋势检验、Pettitt突变检验、Sen’s斜率估计等方法进行了研究。结果表明:章水流域多年平均降雨量为1 599.76 mm，其中春季最多，占全年的37.32%，冬季降雨最少，仅为13.05%。年降水量以0.17 mm/a速率缓慢增加；春、夏和冬季降水量呈现不显著的增加（α=0.10），增加速率分别为0.65，0.60，0.86 mm/a；但秋季降水量表现为显著减少趋势，速率为1.94 mm/a。从空间上来看，年、春和夏3个时段只有零星站点有显著变化趋势和突变，绝大多数站点特征表现稳定，无显著变化趋势和突变发生；而在秋季22个站点中有16个站点有显著的减少趋势，其中有7个站点的显著性超过0.05，主要分布在流域中上游地区，涉及崇义、大余和上犹西部；有10个站点的降雨在冬季具有显著的增加趋势，其中3个站点的显著性超过了0.05，主要分布在流域的中游。仅有个别站点年降水量和春季降雨量发生了突变，夏、秋、冬3个季节降雨突变站点较多在整个流域零散分布，发生时间大多在1992年及前后。

Spatio-Temporal Changes of Precipitation in Zhang River Watershed in the Upper Region of Ganjiang Watershed During 1955-2015

In order to study the precipitation characteristics of the upper region of Ganjiang Watershed, the precipitation was analyzed to examine the trend and abrupt based observed time series data from 22 available rain gauging stations of Zhangshui Watershed of Ganjiang River from the hydrological bureau of Jiangxi Province for the period 1955—2015. The methods of linear regression, moving average method, Sen’s slope estimator and Mann-Kendall trend test were used. The significance and magnitude of precipitation trends were determined using the non-parametric Mann-Kendall test and Sen’s slope, respectively. Pettitt test was also used to examine abrupt change for precipitation. The average annual precipitation was 1 599.76 mm and the precipitation in spring accounted for 37.32%. The portion of winter precipitation was only 13.05%. The annual precipitation appeared an upward tendency with the rate of 0.17 mm/year. The results also showed that most of precipitation occurred in spring and summer and showed the increasing trend at the rate of 0.65 mm/year and 0.60 mm/year in general, respectively. The precipitation in autumn presented the significant decreasing trend with the magnitude of 1.94 mm/year. The spatial distribution of annual, spring and summer precipitation were insignificant in most stations by M-K test, but significant in the upstream part area only in autumn, especially in the western region. There were 10 stations with significant precipitation increasing trend in winter. The obvious abrupt change points of spring precipitation occurred in the year of 1992 in a few of stations. The mutation points were complex and scattered in the whole region in other three reasons.