近60年三峡库区极端降水变化及其与环流指数遥相关分析  

Spatiotemporal Changes of Extreme Precipitation and Its Teleconnection Analysis with Climate Circulation Indices in Three Gorges Reservoir Area in Recent 60 Years

作　　者：曾慧琪 滕顺林 邵蒙 张璐 王跃峰 ZENG Huiqi;TENG Shunlin;SHAO Meng;ZHANG Lu;WANG Yuefeng(School of Geography and Tourism,Chongqing Normal University,Chongqing 401331,China;Chongqing Key Laboratory of Earth Surface Process and Environment Remote Sensing in the Three Gorges Reservoir Area,Chongqing 401331,China)

机构地区：[1]重庆师范大学地理与旅游学院,重庆401331 [2]重庆师范大学三峡库区地表过程与环境遥感重庆市重点实验室,重庆401331

出　　处：《人民珠江》2023年第5期1-9,共9页Pearl River

基　　金：重庆市社会科学规划项目(2020QNGL26);国家自然科学基金项目(42201045);2020年重庆市教育委员会人文社会科学研究规划项目(20SKGH047);重庆市基础研究与前沿探索项目(cstc2021jcyj-msxmX0692);重庆市教委科学技术研究项目(KJQN201900513、KJQN202100520);重庆市大学生创新创业训练计划项目(S202110637049)。

摘　　要：分析大尺度气候环流与极端降水相关性,对区域洪旱灾害预警和极端天气管理意义重大。现有研究较好揭示了单一环流指数的影响,而多种环流的影响特点尚不明确。基于三峡库区1960—2019年21个气象站的逐日降水数据,从降水持续性、绝对性等方面构建8个极端降水指数(CDD、CWD、R10、R20、Rx1d、Rx5d、R95p、R99p),运用Mann-Kendall趋势检验、Spearman相关分析和多元线性回归(MLR)等方法,分析了库区极端降水的时空变化,从单因子和多因子两方面揭示了气候环流与极端降水的相关性。结果表明:(1)近60年,库区R10、R20、Rx1d、Rx5d、R95p、R99p在空间上均呈西北向东南递减状态,与多年平均降水空间趋势相同;(2)CWD、CDD、R10、Rx5d总体呈下降趋势,而R20、Rx1d、R95p和R99p则表现为上升趋势,三峡库区持续降水事件的持续时间有所降低,但短期强降水事件发生的频次和强度均有所增加;(3)从极端降水与环流指数的遥相关分析来看,多因子回归分析对极端降水指数的解释程度优于单因子,其中EASMI和SASMI组合为最强解释因子组合。该研究成果可为三峡库区应对极端气候变化和天气灾害预报预警提供科学依据。Analyzing the correlation between large-scale climate circulation and extreme precipitation is of great significance for regional flood and drought warnings and extreme weather management.Previous studies have well revealed the influence of a single climate circulation index,while the influence characteristics of multiple climate circulation indices are still unclear.According to the daily precipitation in 21 meteorological stations in Three Gorges Reservoir Area(TGRA)from 1960 to 2019,eight extreme precipitation indices(CDD,CWD,R10,R20,Rx1d,Rx5d,R95p,and R99p)were constructed in terms of precipitation duration and absoluteness,and Mann-Kendall(M-K)trend test,Spearman correlation analysis,and multiple linear regression(MLR)were used to analyze the spatiotemporal changes during extreme precipitation in the TGRA.Then the correlation between extreme precipitation and climate circulation was revealed in terms of single and multiple factors.The results showed that:①The R10,R20,Rx1d,Rx5d,R95p,and R99p in the TGRA spatially decreased from northwest to southeast from 1960 to 2019,which was similar to the spatial trend of multi-year average precipitation;②the CWD,CDD,R10,and Rx5d generally decreased,while R20,Rx1d,R95p,and R99p increased.The duration of continuous precipitation events in the TGRA shortened,but the frequency and intensity of short-term strong precipitation events increased;③in terms of teleconnection analysis of extreme precipitation and climate circulation index,the multiple factor regression analysis could better explain the extreme precipitation index than the single factor regression analysis.Specifically,the combination of the East Asian Summer Monsoon Index(EASMI)and the South Asian Summer Monsoon Index(SASMI)had the best performance in explaining the extreme precipitation index.This study can provide a scientific basis for coping with extreme climate change and weather disaster prediction and warning in the TGRA.

关 键 词：极端降水 时空变化 遥相关分析 三峡库区 

分 类 号：P426.6[天文地球—大气科学及气象学]