基于SPEI的陕北黄土丘陵区干旱特征及影响因素分析  

SPEI Based Drought Characters and Factors in Loess Hilly Regions of Northern Shaanxi

作　　者：郭旭新[1] 赵英[1] 高志永[1] 汪有科[2] GUO Xu-xin;ZHAO Ying;GAO Zhi-yong;WANG You-ke(Department of Water Conservancy,Yangling Vocational & Technological College,Yangling 712100,Shaanxi,China;Research Center of Soil and Water Conservation and Ecological Environment,Chinese Academy of Sciences & Ministry of Education, Yangling 712100,Shaanxi,China)

机构地区：[1]杨凌职业技术学院水利工程分院,陕西杨陵712100 [2]中国科学院/教育部水土保持与生态环境研究中心,陕西杨陵712100

出　　处：《西北林学院学报》2019年第1期69-76,共8页Journal of Northwest Forestry University

基　　金：国家支撑计划项目(2015BAC01B03);杨凌职业技术学院科学研究基金项目(A2013029)

摘　　要：为探讨陕北黄土丘陵区干旱特征及其影响因素,借助绥德2000-2014年逐日的气象数据,基于Hargreaves、Thornthwaite和Penman-Monteith蒸散模型及同一套降水资料计算,获得不同时间尺度(月、半年和年)3种标准化降水蒸散指数(SPEI),对比分析上述3种SPEI的差异并选取适宜于陕北黄土丘陵区的SPEI,而后采用SPEI分析干旱特征,并利用通径法分析气象因子对SPEI敏感性。结果表明:1)基于Penman-Monteith蒸散模型的SPEI(SPEI-PM)能够准确反映陕北黄土丘陵区干旱事件,与SPEI-PM相比,基于Hargreaves和Thornthwaite的SPEI值偏低,计算误差为0.26～0.38;2)干旱变化呈现减弱趋势,短时间尺度上(1和6个月)SPEI-PM值变化频繁,长时间尺度上(12、18和24个月)SPEI-PM值变化幅度小且变化周期长;3)在月、半年和年尺度上对SPEI-PM影响程度最大的气象因素分别为气温和相对湿度。In order to explore the drought characteristics and influencing factors in loess hilly region of Northern Shaanxi Province,three types of standardized precipitation evapotranspiration index (SPEI-HG,SPEI-TW,SPEI-PM) in different time scales (month,half year and year) were calculated using precipitation and three sets of potential evapotranspiration (ET) data based on daily climatic data collected from meteorological station of Suide in Shaanxi during 2000 to 2014.The ET was calculated by Hargreaves,Thornthwaite and Penman-Monteith formulae,respectively.Differences between the three types of SPEI were compared and an appropriate SPEI was selected.The drought characteristics were analyzed by the selected SPEI,and the sensitivity of meteorological factors to the selected SPEI was analyzed by path analysis.The results showed that 1) SPEI-PM could accurately describe drought events in loess hilly region of Northern Shaanxi Province.Compared with SPEI-PM,the SPEI-HG and SPEI-TW underestimate drought and the mean absolute errors were 0.26~0.38.2) Drought change showed a decreasing trend,SPEI-PM fluctuation was frequent in short time scale,and stable in long time scale.3) Meteorological factors that mainly affected SPEI-PM on the scale of monthly,half-year and year were the temperature,temperature and relative humidity,respectively.

关 键 词：SPEI 黄土丘陵区 干旱 气象因素 

分 类 号：S728.2[农业科学—林木遗传育种]