摘要
选取1470～2008年间西北四省区19个站点的逐年旱涝等级序列,采用相关分析、累积距平法、移动T检验法和功率谱分析方法,对西北地区近539年的旱涝演变特征及趋势进行分析。结果表明：西北地区总体上以干旱为主,平均发生频率为38%,特别是青海西部达68%;15世纪旱和偏旱发生最为频繁,平均频率达55%,19世纪、20世纪和21世纪旱与涝均增加,旱涝发生更加频繁。各区域旱涝变化趋势具有不同的特点,青海南部、甘肃河西旱涝交替变化,持续时间较短,其余地方旱涝持续时间较长。17世纪40年代到50年代期间,西北地区普遍存在旱涝气候突变,突变时间点由西向东、向南和向北传播和推进;西北地区存在多尺度的周期振动,长周期主要在西北部,东南部以短周期为主,且普遍存在准两年和准三年的短周期振荡。
We described the variation characteristics and the trends of drought- flood grades series of 19 sites in Northwest China from 1470 to 2008 by performing the manners of correlate analysis,accumulative departure analysis,running T- test and power spectral density analysis. Results showed that drought was the main natural calamities which occurred frequently in the special distributions,the mean frequency was 38%,specially in west of Qinghai province,which reached 68%. Drought occurred frequently in 15 century,which reached 55%. The frequency of drought- flood had a increasing trend from 19 century to 21 century. The trend of drought- flood had different characteristics,with shorter duration in south of Qinghai province and in Hexi of Gansu province and with long duration in other areas. Drought- flood climatic jump was universal existence in Northwest China from 1640 s to 1650 s,which spread from West to East,to North and to South. There was mult- scales periodicity in Northwest China,long scale in Northwest and short scale in Southeast. Drought- flood had widely quasi- two and quasi- three years＇ oscillation in Northwest China.
出处
《干旱区资源与环境》
CSSCI
CSCD
北大核心
2015年第5期167-173,共7页
Journal of Arid Land Resources and Environment
基金
中国气象局关键技术集成与应用项目(CMAGJ2013ZX-ZH4)资助
关键词
旱涝
气候突变
周期
趋势
drought-flood climatic jump period trend
