Applicability of meteorological drought index and spatiotemporal characteristics of drought in Jilin Province
[Objective]Jilin Province is the main grain-producing area in China,and it is important to clarify the spatial and tem-poral characteristics of drought in the region to ensure the safety of grain production,while suitable meteorological drought indica-tors are a prerequisite for accurate identification of drought development.[Methods]This study calculates the standardized pre-cipitation index(SPI),percent precipitation distance level(PA),standardized evapotran SPIration 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 PAtial result of the four meteorological drought indices are com PAred with the historical drought records based on the constructed index applicability identification method.The optimum index is iden-tified 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.
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