基于标准化降水指数的干旱变化特征分析——以大庆地区为例  

Analysis of Drought Change Characteristics Based on Standardized Precipitation Index——Taking Daqing as An Example

作　　者：迟道才[1] 张欣雅 陈涛涛[1] 张瑞[2] CHI Dao-cai;ZHANG Xin-ya;CHEN Tao-tao;ZHANG Rui(College of Water Conservancy,Shenyang Agricultural University,Shenyang 110161,China;Jilin Agriculture Science and Technology College,Jilin Jilin 132101,China)

机构地区：[1]沈阳农业大学水利学院,沈阳110161 [2]吉林农业科技学院,吉林吉林132101

出　　处：《沈阳农业大学学报》2018年第2期173-179,共7页Journal of Shenyang Agricultural University

基　　金：国家公益性行业(农业)科研专项项目(201303125);国家自然科学基金项目(51679142;51709173);辽宁省特聘教授基金项目(2013)

摘　　要：干旱是制约大庆地区发展的重要因素,为研究大庆地区干旱变化特征,利用大庆地区5个气象站1960~2015年的逐日气象资料,采用标准化降水指数(standardized precipitation index,SPI),以Z指数为对照,结合历史旱情(以典型年2004和2007年为例进行说明)对大庆地区干旱研究的地区适用性进行了对比,并从干旱强度、干旱历时以及干旱周期角度对大庆地区干旱发生特征进行分析。结果表明:短时间尺度(1~3个月)下,SPI指数对干旱(特别是重旱)的识别能力优于Z指数;在12个月长尺度下二者表现一致。夏季干旱事件(SPI<-1.0)的发生频率最高,为39.29%,其中中等干旱(SPI<-1.5)及重旱(SPI<-2.0)的发生频率约占16.07%;冬季干旱事件发生频率最低,为32.14%。在年尺度上,大庆地区多发生持续时间为7个月及以上的干旱事件,其次为3个月和4个月。大庆地区年际干旱频发,56年间有26年发生了干旱,有5个时间段出现了连旱现象,其中20世纪70年代干旱事件发生次数最多(7次),此后逐年减少。小波分析表明,大庆地区干旱特征呈周期变化,主要周期为2~6,12~15a,24~28a,无论哪个时间尺度,2015年后小波系数实部均呈现正值趋势,表明在未来一段时间内该地区降水偏多。趋势分析表明,大庆地区56年虽年降水量上升不显著,但SPI值上升达到p≤0.01显著水平,说明大庆气候区别于东北的干旱化呈现出显著的湿润化变化。Drought is an important factor restricting the development of Daqing area.In order to study the characteristics of drought in Daqing area,a contrastive analysis was conducted to clarify the feasibility of the Standardized Precipitation Index(SPI)in Daqing area using daily meteorological data of five stations from 1960 to 2015.Daqing historical drought episodes were taken consideration,and Chinese Z index was used as the control index.Meanwhile,four aspects of drought episodes(including magnitude,duration,frequency,and its cycle)were further investigated.The results indicated that at the short-term scale(1-3 months),the SPI index(especially severe drought)was superior to Chinese Z index in the drought recognition,while consistent with Chinese Z index at the 12-month long scale.The occurrence frequency of summer drought event(SPI<-1.0)was the highest(39.29%),of which moderate drought(SPI<-1.5)and severe drought(SPI<-2.0)accounted for 16.07%.Winter drought was the lowest in drought frequency(32.14%).As for the annual scale,long-term drought event(7 months or longer)was mainly occurred in Daqing area,followed by 3 months and 4 months.Inter annual drought occurred frequently in Daqing region.Drought occurred in 26 years within 56 years,and continuous drought occurred in 5 periods.Among them,the frequency of drought in the 1970s was the largest(7 times)and then decreased year by year.Wavelet analysis showed that the characteristics of drought in Daqing area presented periodic changes with the main periods of 2-6a,12-15a and 24-28a.The real part of wavelet coefficients showed a positive trend after 2015,regardless of time scale,indicating that precipitation will be more in the area for some time to come.The trend analysis showed that although the annual precipitation increase was not significant in Daqing region in 56 years,the SPI value increases to a significant level of p<0.01,indicating that the Daqing climate showing a significant change in humidification compared with the aridification in the northeast.

关 键 词：干旱 标准化降水指数 Z指数 小波分析 大庆 

分 类 号：S161.4[农业科学—农业气象学]