西峰区降水特征及变化规律

Characteristics and variation trend of precipitation in Xifeng

利用1960—2010年的逐月降水资料分析了西峰区降水的变化趋势以及突变情况,采用M-K检验法和滑动t检验法分析了西峰区降水量的突变情况。结果表明:降水量总体上呈下降趋势,下降趋势主要由秋季降水量减少引起;年降水、春季降水以及秋季降水分别在1984、1993、1976年发生了一个由多到少的突变,冬季降水在1970年和2000年发生由少到多的转变,汛期降水分别在1986年和1988年出现了由多到少和由少到多的突变。

Based on the monthly precipitation data from Xifeng weather station between 1960 and 2010 ,the varia-tion characteristics and trend of precipitation in Xifeng were analyzed .The results indicated that the overall annual pre-cipitation was apparently in a decrease trend which was mainly caused by reduction of autumn precipitations .The changes were examined by methods including Mann-kendall test and moving t-test .The results found that clear abrupt change points in 1984 ,1993 and 1976 could be detected .From then on ,the annual precipitation ,spring precipitation and au-tumn precipitation began to decline respectively .However ,the winter precipitation began to ascend during 1970-2000 , and precipitation during flood period began to decline from 1986 but ascend from 1988 .