近33年来乌鲁木齐地区雷暴时空变化特征及趋势预测分析

利用1981—2013年新疆乌鲁木齐地区逐月雷暴日数资料,采用线性趋势拟合、Mann-Kendall突变检验、R/S趋势分析以及克里金空间插值等方法,探讨乌鲁木齐地区复杂地形下的雷暴日数的时空分布规律及未来变化趋势。结果表明,近33年来乌鲁木齐地区雷暴空间分布总体表现为山区多于平原、南部多北部少的特征,南部山区为雷暴多发中心,城区、北部平原区及达坂城谷地为低值区域;乌鲁木齐地区雷暴日数呈波动下降趋势,气候倾向率为-1.67 d/10 a;山区下降最为显著,其次为平原区,城区表现为不显著的下降过程;雷暴主要集中在5—8月,7月雷暴频率最高,10月—次年3月基本无雷暴发生。突变检验分析表明,近33年来各区均未出现显著性下降的突变过程,却存在明显的Hurst现象,未来变化趋势存在较强的持续性,即仍将维持下降的态势,城区的持续性强度不大。

Temporal and Spatial Variation Characteristics and Trend Forecast of Thunderstorm in Urumqi Area in Recent 33 Years

Using the monthly thunderstorms data in Urumqi during 1981-2013, the linear trend fitting, Mann-Kendall mutation test, R/S trend analysis and Kriging space interpolation were used to explore the temporal and spatial distribution law and future trends of thunderstorms days in complex terrain of Urumqi.The results showed that the spatial distribution of thunderstorms in Urumqi was characterized by the mountainous area more than plain and south more than north.The southern mountainous area was a thunderstorm multi-center,the urban area, northern plain and Dabancheng valley were low-value areas.The thunderstorm days in Urumqi region showed a trend of falling volatility and climate tendency rate was-1.67 d/10 a.The mountain area was the most significant decline, followed by the plain area,and the decline process performance was not significant in urban area.Thunderstorms were mainly concentrated from May to August, the frequency of thunderstorms was highest in July, almost no thunderstorms occurred from October to next March.Mutation test analysis showed that the district had not been significant decline mutation process in the past 33 years, but there was an obvious phenomenon of Hurst, future trends exist strong sustainability, which will remain down trend, urban sustainability strength is not big.