Analysis on Spatial-temporal Variation Characteris- tics of the Precipitation in Four Provinces of North- west China

• 作者: CHEN Xiao-yan LI Bang-dong TIAN Li WANG Yao ZHANG Xiu-juan
• 来源期刊: 气象与环境研究：英文版
• 学科: 地球科学
• 关键词: 中国西北地区 时空变化特征 降水分析 Morlet小波变换 区域地球化学特征 抽动 季节变化特征 西部地区
• 年，卷（期）: 2012,（8）
• 页码范围: 11-15
• 页数: 5页
• 分类号: P458.121.1

摘要

[Objective]The research aimed to analyze temporal-spatial change characteristics of the precipitation in the four provinces of northwest China. [Method]Based on precipitation data at 113 ground observation stations in the four provinces (Shaanxi,Gansu,Qinghai and Ningxia) of northwest China from 1961 to 2008,by using linear regression and Morlet wavelet transformation,spatial pattern,change trend and periodic characteristics of the precipitation in the zone in 48 years were analyzed. [Result]Rainfall in the four provinces of northwest China had obvious interannual and seasonal change characteristics. Annual,spring and autumn rainfalls all presented decline trends. Summer and winter rainfalls both had slight increase trends,but change trend wasn't obvious. Precipitation change in the four provinces of northwest China had obvious regional difference. Increase amplitudes in Tanggula Mountains,Tsaidam Basin and east Qilian Mountains were obvious. Obvious decrease amplitude existed in east Gansu,south and north Shaanxi. Precipitation in east and west areas of the four provinces in northwest China presented reverse phase change characteristics. Precipitation presented decrease trend in east and increase trend in most areas of west. Precipitation in the whole district,east district and west district generally had 3-5-year short period,which was main period. Precipitation also had 8-year and 15-year medium periods in some areas. Under different time scales,dry-wet alternation and mutation point had difference. [Conclusion]The research provided theoretical basis for studying climate change in northwest China.