摘要
依据1961年-2010年秦岭南北59个气象站逐月降水数据,采用标准化降水指数(Standardized Precipitation Index,SPI)和经验正交函数分解法(Empirical Orthogonal Function,EOF)对秦岭南北旱涝时空变化特征进行了分析。结果显示:①秦岭南北近50a气候总体呈暖干化趋势,降水变化经历了四个时期:正常期-湿润期-干旱期-过渡期;②关中、陕南两地的旱涝等级变化,无论从步调上还是趋势上都基本一致。关中旱涝等级年代波动幅度小于陕南,暖干化程度大于陕南;③EOF分析得出近50a秦岭南北降水主要空间分布类型为:受大尺度气候变暖影响,降水量以秦岭为界,关中地区由北向南纬向递增,陕南呈现西南-东北向带状分布的全区一致型,这是最主要的分布特征。此外受纬度因素、季风气候、小尺度地貌单元等综合因素的影响,有西北(渭北旱塬)-东南(大巴山地区)向的降水分布相反型,以汉中盆地为正值中心的东北-西南向降水分布相反型,以汉江谷地中段为负值中心的东西向降水分布相反型。
With global climate warming, the physical geographic transition zones in climate change has become quite significant. Based on monthly meteorological data from 59 stations in the Qinling Mountains from 1961-2010, we analyzed the spatial and temporal characteristics of drought and flood events using the Standardized Precipitation Index （SPI） and Empirical Orthogonal Function （EOF）. We found that climate in the southem and northern Qinling Mountains presented a warming and drying trend over the last 50 years. Precipitation variation exhibited four periods： the normal period, humid period, dry period and transitional period. The EOF analysis showed that there were four typical precipitation spatial distribution patterns in the southern and northern Qinling Mountains： （1） the whole region identical drought or flood, separated by the Qinling Mountains, the distribution of precipitation increased from north to south in the Guanzhong Plain, while the south of Shaanxi presented a southwest to northeast zonal distribution; （2） the precipitation distribution in the northwest of the study area was contrary to that of the southeastern areas; （3） the precipitation distribution in the southwestern areas, in which Hanzhong Basin was the positive value center, was contrary to that of the northeastern areas; （4） the precipitation distribution in the eastern areas which Hanjiang Valley as the negative value center was contrary to that of the western areas. This study provides a theoretical basis for drought resistance, waterlogging prevention and disaster reduction in southern and northern sections of the Qinling Mountains.
出处
《资源科学》
CSSCI
CSCD
北大核心
2013年第3期638-645,共8页
Resources Science
基金
国家自然科学基金项目(编号:41171090)
关键词
SPI
EOF
旱涝
时空变化
秦岭南北
SPI
EOF
Drought and flood
Spatial and temporal variations
Southem and northern Qinling Mountains
