1951-2015年太原市极端降水事件变化特征研究

The Characteristics of Extreme Precipitation Events in Taiyuan During 1951-2015

根据太原市1951-2015年的逐日降水数据,选取8个极端气候指标,使用趋势分析法对太原市极端降水事件进行分析.结果表明:(1)1951-2015年太原市无降水天数、有效降水间隔频数、极端日降水量和极端降水频数指标呈增加趋势,其中无降水天数增速为5.5 d/10 a,有效降水间隔频数最近30 a增幅明显,极端日降水量和极端降水频数20世纪80年代后波动趋于平缓;(2)有效降水间隔年内最大值(降幅为-9.3 d/10 a)、日最大降水量指标呈下降趋势;(3)太原市首次有效降水出现日期与日最大降水量出现日期均有提前的趋势,其中首次有效降水出现日期的年际倾向率为-7.6 d/10 a,而末次有效降水出现日期略微推迟,年际倾向率为1.7 d/10 a,日最大降水量出现日期有集中于8月初(第210天到第220天)的变化趋势.

Extreme precipitation events of Taiyuan city were analyzed based on the rainfall data during 1951-2015.Eight extreme climate indicators were selected and the trend analysis method was adopted.The results show that:(1)the number of days without precipitation,the frequency of effective precipitation interval,extreme daily precipitation and its frequency were all increased during 1951-2015,and the increasing rate of the no precipitation day shows 5.5 d/10 a,the frequency of effective precipitation intervals increased obviously in the last 30 years,whereas the extreme daily rainfall and frequency of extreme tend to be gentle after1980s.(2)the maximum value of interval of effective precipitation(rate:-9.3 d/10 a)and the daily maximum precipitation showed a downward trend.(3)the dates of the first effective precipitation day(rate:-7.6 d/10 a)and the maximum precipitation day were both present an earlier trend,while the last date of the effective precipitation was slightly delayed(rate:1.7 d/10 a),and the dates of the maximum value of daily precipitation has a tendency to concentrated on the beginning of August(day 210 th to 220 th).