摘要
利用东北地区(黑龙江、吉林、辽宁)1960—2014年90个气象台站的逐日地面观测数据(平均气温、降水量、日照时数、平均相对湿度、平均风速及平均水汽压),利用标准化降水指数(SPI)和标准化降水蒸散指数(SPEI),对比分析近55 a多时间尺度干旱变化特征及两指数的表征差异。(1)依据各气象台站年总降水量,可将东北地区分为5个子区,各分区年总降水量皆未表现出显著的长期趋势,但Ⅰ、Ⅱ、Ⅳ区和Ⅴ区年总潜在蒸散量分别呈现显著下降、上升趋势。(2)两指数在1个月(1 mo)尺度上围绕0值频繁波动,随时间尺度增加,形成干湿阶段持续期,其中干旱期持续时间较湿润期稍长。不同时间尺度二者评估旱涝结果总体相似,其中短时间尺度,SPI较SPEI易受降水影响,波动大。长时间尺度差距减小,但在判别程度上SPI较SPEI偏轻。在特殊干旱年1982年和1999年,SPI在降水量减少幅度较大地区或月份监测干旱能力下降。(3)SPI描述东北地区无旱及特旱发生频率时较SPEI高,中旱、重旱及湿润发生频率则相反。(4)在评估东北地区旱涝情况时SPEI指数较SPI指数适用性更好。
In this paper,the standardized precipitation index（SPI） and the standardized precipitation evapotranspiration index（SPEI） were used to analyze the drought variation at multiple temporal scales and the difference between SPI and SPEI performance in northeast China（Heilongjiang,Jilin and Liaoning provinces）,the two indexes were calculated using the daily ground observation data including the average air temperature,precipitation,sunshine duration,average relative humidity,average wind speed and average vapor pressure at 90 meteorological stations during the period of 1960-2014. The results are as follows：（1） The study area was divided into 5 subareas according to REOF method based on annual precipitation,there was no significant trend of annual precipitation in all the subareas,but the annual evapotranspiration was significantly in a decrease tend in subarea I,subarea Ⅱ,subarea Ⅳ and an increase trend in subarea V;（2） SPI/SPEI values fluctuated frequently at a 1-month scale,and the persistent drought and wet durations formed with the increase of temporal scale,in which the drought duration was slightly longer than the wet duration. Generally,SPI and SPEI performed the similar results in evaluating drought at all the time scales,SPI fluctuated widely at shorter time scales,because it was easily affected by precipitation,whereas the drought degree of SPI was underestimated compared with that of SPEI at longer time scales. In1982 and 1999 when severe drought occurred,the capability of indicating drought by SPI descended in some areas where precipitation was significantly decreased or in some months when the similar situation occurred;（3） The occurrence frequencies of non-drought and extreme drought described by SPI were higher than that by SPEI in northeast China,but the situation was opposite in describing the moderate drought,severe drought and humidity;（4） SPEI was more suitable than SPI in evaluating drought and flood in northeast China.
出处
《干旱区研究》
CSCD
北大核心
2017年第6期1250-1262,共13页
Arid Zone Research
基金
国家自然科学基金(31201124)
国家重点研发计划项目(2016YFD0300103)
沈阳大气环境研究所公益性科研院所基本科研业务费(2016SYIAEZD1)共同资助
关键词
标准化降水指数
标准化降水蒸散指数
多时间尺度
干旱变化
东北地区
standardized precipitation index
standardized precipitation evapotranspiration index
Multi-scale
Drought variation
Northeast China
