摘要
根据1961-2007年四川地区123个测站的逐日降水资料和NCEP/NCAR逐月再分析资料,采用Z指数作为旱涝等级划分标准,分析了四川地区旱涝出现的频率,采用EOF、REOF分析、趋势分析、滑动t检验以及小波分析等方法,研究了四川地区旱涝灾害发生、发展的空间演变特征及时间变化趋势。结果表明,该地区旱涝事件的空间分布可分为4个区,分别是四川盆地东部区、西部区、川西南山地区和川西高原区。从时间变化趋势上看,四川盆地东部区、川西南山地区和川西高原区由偏旱逐渐向偏涝转变;而四川盆地西部区由偏涝逐渐向偏旱转变。4个分区的周期振荡特征显著,有明显的年际变化和年代际变化。夏季西太平洋副热带高压及南亚高压位置的南北变化、高原季风的强弱变化分别对四川盆地东部区、西部区及川西高原区的旱涝事件有显著的影响。
The frequencies of drought and flood events in Sichuan were analyzed based on the daily precipitation data at 123 stations in summer from 1961 to 2007 and the NCEP/NCAR monthly reanalysis data,taking Z index method as classify the drought and flood grades.In addition,the EOF,REOF,linear trend,running t test,and wavelet analysis methods were used to analyze the temporal and spatial change trends of drought and flood events in Sichuan.The analyzed results are as follows： Drought and flood events in Sichuan region in summer can be identified into four regions,namely,east Sichuan basin,west Sichuan basin,southwest Sichuan mountain region,and western Sichuan Plateau. As to the temporal change trend,it changes from drier to weter in east Sichuan basin,southwest Sichuan mountain region and western Sichuan Plateau,whereas the trend in west Sichuan basin is from weter to drier.In the four regions,the interannual and interdecadal changes in the drought and flood events are obvious.The fluctuating of west Pacific subtropical high and South Asia high and the intensity of plateau monsoon have significant impacts on drought and flood events in east Sichuan basin,west Sichuan basin,and western Sichuan Plateau.
出处
《高原气象》
CSCD
北大核心
2011年第5期1170-1179,共10页
Plateau Meteorology
基金
成都高原气象研究所基本科研项目(BROP201016)
成都高原气象研究所高原气象开放基金项目(LPM2009008)共同资助
关键词
四川地区
旱涝等级
高原季风
Sichuan region
Flood and drought grades
Plateau monsoon
