大理地区极端气候事件长期变化特征研究

Study on the Long-term Change of Extreme Climate Events in Dali Area

利用大理气象站的1960—2014年逐日降水和气温资料,计算出12个极端气候指数,采用线性趋势分析,M-K方法、Pettitt法相结合和谐波分析等方法对极端气候指数的趋势、周期和突变进行分析,得出如下结论:(1)整体来看,大理地区的极端降水指数中,最大1 d降水量、大雨日数、连续湿日、强降水量以及年降水量分别以1.278、0.211、0.1、6.987、15.25 mm/10a的趋势在减少,降水强度以0.03 mm·d-1·(10 a)-1的趋势增加;极端温度指数中,年平均温度以0.15℃/10a的趋势在增加,暖昼、暖夜、热持续天数的增加速率分别为43%、39%、2.56 d/10a,冷昼、冷夜、冷持续日数分别以5%、43%、0.8 d/10a的趋势在减少;(2)极端降水指数中存在4、6、20、27 a不同的主周期变化;极端温度指数中,冷夜、暖夜、暖昼、冷持续指数的主周期为27a,与年平均气温的周期变化一致;(3)热持续日数和暖昼的大幅变化对大理地区的增温现象产生一定影响;(4)年降水量在2011年发生突变,其它极端降水指数均未检测到显著性突变,年平均气温在2006年发生显著性突变,冷夜、暖夜、暖昼指数在90年代前后发生突变,并且均通过了0.01的显著性检验。

Based on the daily temperature and precipitation data of Dali meteorological station in 1960—2014,12 extreme climate indices were selected to analyze the trends, cycles and change points of precipitation and temperature by the linear trends analysis,Mann-kendallPettitt and harmonic analysis. The results showed that,firstly,in the extreme precipitation indices,the trends of maximum 1-day precipitation,heavy rainfall days, continuous wet days,heavy rainfall and annual precipitation was going down by 1. 278,0. 211,0.1,6. 987,15. 25 mm/10 a,respectively. While the precipitation intensity was increased by 0. 03 ·mm d-1·（ 10 a）-1. In the extreme temperature indices,the annual average temperature increased at rates of 0. 15℃/10 a. The increase rate of warm days, warm nights and heat duration was 43%, 39%, and 2. 56 d/10 a, respectively. While, the trend of cold days, cold nights and cold duration was decreased by 5%, 43% and 0. 8 d/10 a, respectively. Secondly, the extreme precipitation indices existed in different main cycle changes such as 4 a, 6 a, 20 a and 27 a. In the extreme temperature indices,the main cycle of cool nights,warm nights,warm days and cold duration was 27 a, which was consistent with the annual mean temperature. Thirdly, the significant changes of heat duration and warm days would have a certain effect on the warming phenomenon in Dali area. Fourthly,the annual precipitation had a sudden change in2011,but no significant mutation was detected in other precipitation indices. The annual average temperature had a significant mutation in 2006. Cold night, warm night and warm day index mutated before and after 1990 s,which were all passed the 0. 01 significance test.