沙漠与绿洲气象
沙漠與綠洲氣象
사막여록주기상
Desert and Oasis Meteorology
2015年
4期
17-24
,共8页
新疆%降水距平%集合经验模态分解%本征模函数%区域差异
新疆%降水距平%集閤經驗模態分解%本徵模函數%區域差異
신강%강수거평%집합경험모태분해%본정모함수%구역차이
Xinjiang%precipitation anomaly%ensemble empirical mode decomposition%intrinsic mode function(IMF)%regional difference
降水是中国西北干旱区水资源的重要组成部分，利用合理方法有效认识降水的区域变化规律对指导农业发展尤为重要。基于新疆16个国际交换站1961—2012年降水距平时间序列，利用集合经验模态分解（EEMD）方法，分析了新疆降水变化趋势的多尺度特征，并对其空间差异进行了初步探讨。近50多年来，新疆降水量整体上呈现出非线性的显著增多趋势，且其变化存在明显的年际尺度（3a和6a准周期）和年代际尺度（10a和31a准周期）；各周期分量方差贡献率显示年际变化在新疆降水变化中占据主导地位，重构的降水年际变化趋势能精细刻画原始降水序列在研究时期内的波动状况；降水年代际变化揭示了新疆降水在1987年前后气候模态有了显著转换，由原来降水以负相位为主的气候模态转向正相位显著的气候模态；此外，降水变化趋势和转折时间均具有明显的区域差异。EEMD方法有助于加深人们对新疆降水多尺度变化特征的认识，是一种适用于非线性、非平稳信号分析的有效方法。
降水是中國西北榦旱區水資源的重要組成部分，利用閤理方法有效認識降水的區域變化規律對指導農業髮展尤為重要。基于新疆16箇國際交換站1961—2012年降水距平時間序列，利用集閤經驗模態分解（EEMD）方法，分析瞭新疆降水變化趨勢的多呎度特徵，併對其空間差異進行瞭初步探討。近50多年來，新疆降水量整體上呈現齣非線性的顯著增多趨勢，且其變化存在明顯的年際呎度（3a和6a準週期）和年代際呎度（10a和31a準週期）；各週期分量方差貢獻率顯示年際變化在新疆降水變化中佔據主導地位，重構的降水年際變化趨勢能精細刻畫原始降水序列在研究時期內的波動狀況；降水年代際變化揭示瞭新疆降水在1987年前後氣候模態有瞭顯著轉換，由原來降水以負相位為主的氣候模態轉嚮正相位顯著的氣候模態；此外，降水變化趨勢和轉摺時間均具有明顯的區域差異。EEMD方法有助于加深人們對新疆降水多呎度變化特徵的認識，是一種適用于非線性、非平穩信號分析的有效方法。
강수시중국서북간한구수자원적중요조성부분，이용합리방법유효인식강수적구역변화규률대지도농업발전우위중요。기우신강16개국제교환참1961—2012년강수거평시간서렬，이용집합경험모태분해（EEMD）방법，분석료신강강수변화추세적다척도특정，병대기공간차이진행료초보탐토。근50다년래，신강강수량정체상정현출비선성적현저증다추세，차기변화존재명현적년제척도（3a화6a준주기）화년대제척도（10a화31a준주기）；각주기분량방차공헌솔현시년제변화재신강강수변화중점거주도지위，중구적강수년제변화추세능정세각화원시강수서렬재연구시기내적파동상황；강수년대제변화게시료신강강수재1987년전후기후모태유료현저전환，유원래강수이부상위위주적기후모태전향정상위현저적기후모태；차외，강수변화추세화전절시간균구유명현적구역차이。EEMD방법유조우가심인문대신강강수다척도변화특정적인식，시일충괄용우비선성、비평은신호분석적유효방법。
Precipitation is the most key factor for water resources in the arid region of northwest China. Therefore, it is especially important for guiding agricultural development to understand the regional characteristics of precipitation with effective and reasonable methods. Based on precipitation anomaly time series from 16 international exchange stations in Xinjiang during the period from 1961 to 2012, the multi-scale characteristics of precipitation variability were analyzed using ensemble empirical mode decomposition (EEMD)method. Regional differences in variation trend and change-point were also preliminarily discussed. In the last more than 50 years, the overall precipitation in Xinjiang has exhibited a significant non-linear upward trend, and its changes have obviously presented an inter-annual scale (quasi-3 and quasi-6-year)and inter-decadal scale (quasi-10 and quasi-31-year); The variance contribution rates of each components proved that the inter-annual change had a strong influence on the overall precipitation change in Xinjiang, and the reconstructed inter-annual variation trend could describe the fluctuation state of original precipitation anomaly during the study period. The reconstructed inter-decadal variability revealed that the climate mode in Xinjiang had a significant transformation before and after 1987, namely the precipitation anomaly shifting from a negative phase to a positive one. Furthermore, there were obviously regional differences in the non -linear changes and change-points of precipitation. At the same time, the results also suggested that the EEMD method can effectively reveal variations in long-term precipitation at different time scales and can be used for the complex diagnosis of non-linear and non-stationary signal changes.
