1951—2008年中国西北干旱区降水时空变化及其趋势  

Spatio-temporal Change and Trend of Precipitation in Northwest China During 1951-2008

作　　者：徐利岗[1,2] 周宏飞[1] 杜历 鲍子云 

机构地区：[1]中国科学院新疆生态与地理研究所阜康荒漠生态系统国家野外观测研究站,新疆阜康8315052 [2]宁夏水利科学研究院,宁夏银川750021

出　　处：《中国沙漠》2015年第3期724-734,共11页Journal of Desert Research

基　　金：中国博士后科学基金项目(2013M542416);中国科学院知识创新工程重要方向项目(KZCX2-YW-T09);国家国际科技合作项目(2010DFA92720);国家重点基础研究发展计划项目(2009CB421301)

摘　　要：在全球气候变化背景下,地处生态脆弱区的中国西北干旱区降水响应特征及其未来变化趋势的量化研究极为重要,依据中国西北干旱区95个站点1951—2008年月降水资料,运用自然正交分解法(EOF)、Morlet小波分析、轮次分析、游程理论、极差分析、季节性指数分析、Mann-Kendall检验及气候趋势系数分析等方法分析了西北干旱区降水时空变化特征及其未来趋势。结果表明:西北干旱区降水场前4个特征向量累计方差贡献率达81.61%,第一特征向量最高为48.53%,属"相间复杂"型,依据其荷载空间分布特征将研究区划分为北疆子区、南疆子区、河西子区、青海子区及内蒙古子区;西北干旱区及各子区降水存在9年及12年主周期;各地的极大丰水历时均小于极限枯水历时,单独丰水年的概率高于单独枯水年,连枯年的概率高于连丰年,干旱主要发生在新疆和河西地区;降水序列具有长期相关性,Hurst系数在0.629~0.845间波动;西北干旱区40.0%的地区降水具有明显的季节性分布;61%地区重现性指数大于0.7,降水年内分配的年际差异较小;86.3%地区降水量呈增加趋势,其中20.0%通过信度0.01的显著性检验,48.4%通过了0.05显著性检验,增幅16.6~0.1mm/10a;11.6%地区呈减少趋势,减幅为5.2~0.3mm/10a。Under the global climate change,quantitative research on response characteristics of precipitation to global climate change and its future trend in northwest China is very important.Using empirical orthogonal function(EOF),morlet wavelet analysis,the run theory,displacement theory,extremum deviation theory,seasonal index method(RI),the Mann-Kendall rank correlation method and climatic trend coefficient method,the spatial distribution and the multiple-time scale variability of precipitation are analyzed by the monthly precipitation data from 95 meteorological stations in northwest China during 1951-2008.Results indicate that:(1)The contribution of the overall changes rates of the first four characteristic vector was 81.61%,the first vector of precipitation spatial distribution pattern was primarily complex(contribution to the overall changes was 48.53%),the research area can be divided into five sub-regions accordingly.(2)There were primary cycles of 9years and 12 years for the precipitation series.(3)The probability of single abundant precipitation year was higher than single short precipitation year and the continuous short precipitation year was higher than continuous abundant precipitation year.Drought occurred mainly in Xinjiang and the Hexi Corridor.The Hurst coefficient was 0.629-0.845,so the precipitation series had durative characters.(4)There was 40% area of northwest China with a clear seasonal distribution;61% area reproducibility index(RI)value were greater than 0.7,showing that in most area annual rainfall distribution was stable and had a less differences for inter-annual precipitation.(5)The 86.3%area showed an increasing trend(20% and 48.4% of the stations passed 0.01 and 0.05 significance test),and increase ratio was 16.6-0.1mm/10 a,and 11.6% area decreased with 5.2-0.3mm/10 a.

关 键 词：西北干旱区 降水 时空变异 趋势分析 MANN-KENDALL法 

分 类 号：P468.024[天文地球—大气科学及气象学]