西安市区近61年降水量年际变化规律研究

Study on the Interannual Variation Rule of 61-year Precipitation in Xi'an Urban Area

为揭示西安市区降水量的年际变化规律,根据西安气象站1956年～2016年的降水资料,采用线性趋势、累积距平、5年滑动平均和Mann-Kendall检验法共4种方法,分析西安市区年降水量的变化规律和突变情况。结果表明:西安市区多年平均降水量为565.98 mm,最大值为1983年903.2 mm,最小值为1977年346.2 mm。极值比2.61,降水量年际变化具有波动性,总体呈减少趋势,但并不明显。突变发生在1965年、2014年、2015年,1965年始降水量下降,其中1978年～1980年、2001年～2002年的降水量统计值超过了临界线,说明这几年的降水量下降趋势显著。

In order to open out the interannual variation rule of precipitation in Xi＇an urban area, according to the precipitation data of Xi＇an Meteorological Station from 1956 to 2016, four kinds of methods, such as the linear trend, the cunmlafive departure, 5-year moving average and Mann-Kendall test were used to analyze the variation and mutafion of annual precipitation in Xi＇an urban area. The results show that the average annual precipitation is 565.98mm, the maximum value is 903.2mnl in 1983. The ininimum value is 346.2mm in 1977. The extreme value ratio is 2.61. The interannual variation of the precipitation in Xi＇an urban area is fluctuating, the overall trend is decreasing, but it is not obvious. The mutation occurred in 1965, 2014 and 2015, from 1965 the trend of precipitation decline, among which, the statistical value of precipitation tor 1978-1980 and 2001-2002 exceeded the threshold, indicating that the downward trend is significant tor tbese years.