西安市近58年雨涝事件时间序列特征研究  

Analysis on the Temporal Characteristics of Waterlogging about the Recent 58 Years in Xi'an

作　　者：廖光明[1] 延军平[1] 胡娜娜[1] 安华[1] 

机构地区：[1]陕西师范大学旅游与环境学院,陕西西安710062

出　　处：《灾害学》2013年第2期65-70,共6页Journal of Catastrophology

基　　金：国家自然科学基金项目"部分重大自然灾害的时空对称性:结构;机理与适应对策"(41171090)

摘　　要：利用西安市1951-2008年逐日气象数据,以Z指数方法定义西安市雨涝指数,结合大雨、暴雨等主要强降水雨涝事件发生频次变化特征,揭示出西安市近58年雨涝灾害时间序列变化特征以及周期规律。结果表明:西安市近58年平均气温以0.38℃/10 a的倾向率明显上升,而降水量线性变化趋势不显著。年均大、暴雨日数发生频次相对较少,变化较为随机,但暴雨强度有明显上升趋势。采用Morlet小波变换,对大、暴雨日数及雨涝指数进行多时间尺度周期分析,大、暴雨日数和7、8月雨涝指数具有较一致的准6年周期变化特征。9月雨涝指数主要存在10年和20～25年两个振荡周期。各要素存在着不同时间尺度周期变化特征,大尺度周期内包含着次一级小尺度变化,不同时间阶段具有不同尺度周期变化。小波系数分布趋势显示未来10年,西安或仍将处于降水丰富、暴雨易发的雨涝期。Based on the daily precipitation data from 1951 to 2008,the waterlogging indices were assessed with Z-index in Xi＇an.Simultaneously,this paper analyzed changes of the frequencies about severe rainfall,and then revealed the temporal characteristics and the periodic variation of the waterlogging in recent 58 years.The results showed that： the trend of annual mean temperature appeared to be warmer by the 0.38℃/10a rate,however,the tendency of the precipitation not obvious.Globally,the climate had warming and drying trend.The frequencies of severe rainfall days were relatively less,and had an unobvious change trend.The intensity of the rainstorm trended to rise significantly.The precipitation showed an uneven distribution each month.The waterlogging in 7 month occurred frequently,but the grade and intensity were relatively higher in 9 month.This paper analyzed the periodic rules of heavy rain,rainstorm days and waterlogging indices with the Morlet wavelet transformation,and found that the periodic variation of heavy rain and torrential rain were synchronous.There were obvious periodic cycles of 6a in 7 and 8 month,and 20-25a in 9 month.Overall,the precipitation had the characteristics of multiple time scales,different time scales showed the different cyclic-alternating-patterns,and the periodic variation on large scales was nesting the periodic variation on small scales.Distribution trend of wavelet coefficients showed that Xi＇an would be a frequently-occurring stage of waterlogging in the coming 10 years.

关 键 词：西安市 雨涝事件 Z指数 小波分析 

分 类 号：P468[天文地球—大气科学及气象学] X43[环境科学与工程—灾害防治]