大连地区干旱特征及变化趋势分析

Analysis of Drought Characteristics and Changing Trends in Dalian Region

为探究气候变化背景下大连市干旱特征及变化趋势,基于2007~2023年大连市80个区域自动气象站和1964~2023年6个国家气象站的气象数据,使用相对湿润度指数探讨分析了大连市干旱的时序变化趋势、空间分布规律及概率分布特征。结果表明:(1)大连市干旱主要以轻旱为主,发生轻旱的区域主要分布于瓦房店、旅顺和大连市区。相对湿润的区域为东北部地区,相对干旱的区域为西北部地区和旅顺、市区及长海的部分地区。春季以轻旱和中旱为主,瓦房店、旅顺、市区和金普新区的部分地区为中旱,庄河、普兰店和长海大部为轻旱。秋季庄河和普兰店的部分区域为无旱,其他大部分地区以轻旱为主。(2)干旱发生频率较低的区域基本在庄河地区,干旱发生频率较高的地区基本在瓦房店西北部及大连市南部地区的大部分区域。(3)近60年大连市相对湿润度指数呈显著上升趋势,即干旱程度显著减弱。春季、秋季及冬季相对湿润度指数均出现显著上升趋势,干旱显著减弱。(4)近60年大连市的相对湿润度在2002~2003年开始了突变,在2012~2014年发生了突变。(5)近60年大连市无旱年占45%,轻旱年占52%,中旱年占3%,无重旱及特旱年。

In order to explore the characteristics and trends of drought in Dalian under the background of climate change,based on meteorological data from 80 regional automatic meteorological stations in Dalian from^(2)007 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 areas of Dalian city.(3)In the past 60 years,the relative humidity index in Dalian has shown a significant upward 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^(2)002 to 2003,and a sudden change occurred from^(2)012 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.