大连地区干旱特征及变化趋势分析OACSTPCD

In order to explore the characteristics and trends of drought in Dalian under the background of cli-mate change,based on meteorological data from 80 regional automatic meteorological stations in Dalian from 2007 to 2023 and 6 national meteorological stations from 1964 to 2023,the relative humidity index was used to explore and analyze the temporal,spatial,and probability distribution characteristics of drought in Dalian.The results show that:(1)Drought in Dalian City is mainly characterized by light drought,and the areas where light drought occurs are mainly distributed in Wafangdian,Lushun,and the urban area of Dalian.The relatively humid areas are the northeast region,while the relatively arid areas are the northwest region and parts of Lushun,urban areas,and Changhai.Spring is mainly characterized by mild and moderate drought,with some areas in Wafangdian,Lushun,urban area,and Jinpu New Area experiencing moderate drought,while most areas in Zhuanghe,Pulandian,and Changhai experiencing mild drought.In autumn,some areas of Zhuanghe and Pulandian are drought free,while most other areas are mainly characterized by mild drought.(2)The areas with lower frequency of drought occurrence are mainly in Zhuanghe area,while the areas with higher frequency of drought occurrence are mostly in the northwest of Wafangdian and most of the southern are-as of Dalian city.(3)In the past 60 years,the relative humidity index in Dalian has shown a significant up-ward trend,indicating a significant reduction in the degree of drought.The relative humidity index showed a significant upward trend in spring,autumn,and winter,while drought significantly weakened.(4)In the past 60 years,the relative humidity of Dalian City began to undergo a sudden change from 2002 to 2003,and a sudden change occurred from 2012 to 2014.(5)In the past 60 years,Dalian has had 45%drought free years,52%mild drought years,3%moderate drought years,and no severe or extreme drought years.