根据邢台市国家气象观测站1954-2014年的逐日降水资料,运用线性倾向分析、Mann-Kendall突变检验、滑动t检验等方法对邢台市的降水气候变化特征进行了分析.结果表明:近61 a来,邢台市月不同等级降水日数随着降水等级的升高而快速下降,月雨日和月雨量的峰值均出现在7月份,平均为18.67 d和150.46 mm;小雨日和小—中雨日分别呈-3.17 d·10a-1和-0.61 d·10a-1的显著性下降,其他等级降水的雨日也都呈不明显的下降趋势,年总雨日呈-4.37 d·10a-1的显著性下降,其中在夏季的下降趋势最明显;年总雨量的气候倾向率为-18.23mm·10a-1,其中小雨量呈-5.22 mm· 10a-1的显著下降;总雨量下降的原因一方面是雨日的减少,另一方面是小雨日和小—中雨日雨量在夏季的显著性减少.检验证明小雨日、小—中雨日的突变时间分别在20世纪70年代中后期和60年代末,总雨日和小雨量的突变时间分别发生在20世纪70年代初和80年代初.%Based on the daily precipitation data from 1954 to 2014 at Xingtai meteorological observatory in Hebei Province,the characteristics of precipitation variation were analyzed with the methods of linear trend analysis,Mann-Kendall mutation test and sliding t test.The results showed that the rainy days in each month declined rapidly along with the increase of rainfall grades,and the maximum monthly rainfall mount and rainy days appeared in July,being 18.67d and 150.46mm in average,respectively.The light rain days and light-moderate rain days showed a significant decrease by-3.17 d· 10a-1 and-0.61 d· 10a-1,respectively,while the days with other rain grades tended to decrease insignificandy;the total annual rainy days showed a significant decrease by-4.37 d· 10a-1,in which the most obvious decline occurred in summer.The climate tendency rate of annual total rainfall was-18.23 mm· 10a-1,in which the amount of light rain declined significantly by-5.22 mm· 10a-1.The decline in total rainfall was caused by both the decrease of rainy days and the significant decrease of rainfall amount in light rain days and light-moderate rain days in summer.Furthermore,it was found that the mutation time of light rain days and light-moderate rain days was the mid and late 1970s and the end of 1960s,respectively,while the mutation time of total rain days and light rain amount was the early 1970s and the early 1980s,respectively.
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