吉林省气象干旱指标适用性及干旱时空演变特征研究

Applicability of meteorological drought index and spatiotemporal characteristics of drought in Jilin Province

【目的】吉林省是我国主要的粮食主产区,明确该地区干旱时空特征对于保障粮食生产安全具有重要意义,而适宜的气象干旱指标是准确识别旱情发展的前提。【方法】研究基于吉林省55个气象站点1960—2020年逐月降水和气温数据,计算标准化降水指数(SPI)、降水距平百分率(PA)、标准化蒸散指数(SPEI)和相对湿润度指数(MI)3和12个月结果。构建指标适用性识别方法,实现4种气象干旱指数季节尺度监测结果与旱灾记录定量化精准识别分析,并基于最适宜指数分析研究全省年代际、年际和季节的干旱演变特征。【结果】研究结果表明:(1)4种指数监测准确率由高到低分别为SPI(71.15%)、PA(66.67%)、SPEI(66.03%)和MI(55.77%)。(2)年代际尺度,1980 s前吉林省易旱地区主要集中在东部地区吉林市和延边州,干旱频率均高于40%;1980 s后,高值区域转移到吉林省西部白城和松原市,干旱频率均高于20%。(3)年尺度、春、秋和冬季均呈显著湿润化趋势,干旱强度倾向率分别为-1.761%/10 a、-0.124%/10 a、-0.068%/10 a和-0.054%/10 a。【结论】SPI指数是4种指标中最适用于吉林省的指数,全省易旱地区从东南地区转移到西北地区,且中西部地区是干旱高发区。研究结果可为全省旱情监测、农业生产及旱灾防御指挥决策等工作提供参考借鉴。

[Objective]Jilin Province is the main grain-producing area in China,and it is important to clarify the spatial and temporal characteristics of drought in the region to ensure the safety of grain production,while suitable meteorological drought indicators are a prerequisite for accurate identification of drought development.[Methods]This study calculates the standardized precipitation index(SPI),percent precipitation distance level(PA),standardized evapotran SPI ration index(SPEI)and relative wetness index(MI)3 and 12-month result,based on the monthly precipitation and temperature data of 55 meteorological stations in Jilin Province from 1960 to 2020.The seasonal scale s PA tial result of the four meteorological drought indices are com PA red with the historical drought records based on the constructed index applicability identification method.The optimum index is identified quantitatively and precisely,and the interdecadal,interannual and seasonal drought evolution characteristics of the province are analyzed.[Results]The result of the study show that:(1)The four indices are monitored with the highest to lowest accuracy of SPI(71.15%),PA(66.67%),SPEI(66.03%),and MI(55.77%).(2)On an interdecadal scale,the drought-prone areas in Jilin Province before 1980 s are mainly concentrated in Jilin City and Yanbian Prefecture in the eastern region,both with drought frequencies higher than 40%;after 1980 s,the high value areas shift to Baicheng and Songyuan City in western Jilin Province,both with drought frequencies higher than 20%.(3)The annual scale,spring,autumn and winter all show significant wetting trends,with drought intensity tendency rates of-1.761%/10 a,-0.124%/10 a,-0.068%/10 a and-0.054%/10 a,respectively.[Conclusion]The SPI index is the most applicable index among the four indicators to Jilin Province,where the drought-prone areas of the province shift from the southeast to the northwest,and the central and western regions are drought-prone areas.The result of the study can provide reference for drought monitoring,agricultural production and drought defense command decision making in the province.