左权县1961—2015年降水变化特征及对农业生产的影响

为了掌握左权县降水变化规律,笔者利用左权县1961—2015年逐月降水资料,采用线性趋势、5年滑动平均、M-K检验和滑动t检验等方法,分析左权县年及季节降水量变化趋势和突变特征。结果表明：左权县年降水量总体以-12.6 mm/10 a速率下降,20世纪60—90年代呈减少趋势,21世纪以来呈增加趋势,且在1968年发生了减少突变;季节降水量变化,春、夏、秋季呈减少趋势,冬季则呈微弱增加趋势,夏、秋季降水年代际变化与年降水变化趋势一致,冬、春季降水年代际变化起伏较大,秋季在1970年发生了减少突变,春季在2005年发生了由少到多的跃变,冬季在1976年和2003年分别发生了由多到少和由少到多的转变;干旱和暴雨是影响当地农业生产主要气象灾害。

Precipitation in Zuoquan During 1961-2015: Variation Characteristics and the Impact on Agriculture

To grasp the variation rule of precipitation in Zuoquan, based on the monthly precipitation data from 1961 to 2015 of Zuoquan, we analyzed the variation trend and mutation characteristics of annual and seasonal precipitation in Zuoquan by using the methods of linear trend, 5-year moving average, M-K test and sliding t test. The results showed that: the annual precipitation in Zuoquan overall decreased at a rate of-12.6 mm/10 a, and had a decreasing trend in the 1960s-1990s and an increasing trend since the beginning of the 21 ^st century and there was a reduction mutation in 1968; seasonal precipitation variation showed a decreasing trend in spring, summer and autumn, and a slight increasing trend in winter, the inter decadal variation of precipitation in summer and autumn was consistent with the annual precipitation variation trend, but it fluctuated greatly to the precipitation in winter and spring, and the reduction mutation occurred in autumn of 1970, and the precipitation in spring mutated from less to more, and the precipitation in winter mutated from more to less and from less to more in 1976 and 2003, respectively; drought and rainstorm were major meteorological disasters affecting local agricultural production.